Solar Energy Technology Roadmap of South Africa

[SOLA R E N E R G Y TEC H NOLOG Y ROA D M A P OF SOUT H AF R IC A ] A p r i l 1 4, 20 10

So l a r

E n e r g y Te c h n o l o g y R o a d m a p o f S o u t h A f r i c a

A p r i l 1 4

20 10

T h e S E T R M is t he i n ves t i ga t i o n o f a so la r ener g y te c h n o l o g y r oa d m a p f o r S o u t h A f r i c a, w h i c h ta ke i n t o c o ns i de r a t i o n t he d r a f t ene r g y resea r c h, de ve l o p m e n t an d i n n o va t i o n (ER D & I) st ra te g y d r i v e r s w h i c h i n c l u de u n i v e rsa l ac cess, ec o n o m i c g r o w t h, an d en v i r o n m e n ta l p r o te c t i o n as a f r a m e w o r k. T h e r o a d m a p a ls o h i g h l i g h ts k e y st ra te g i c f o c us a reas, re q u i r e d i n te r v e n t i o ns b y v a r i o us r o l e p l a ye rs an d h o w bes t S o u t h A f r i c a m a y use i ts c o m p a ra t i v e ad v a n ta ge o f so la r i r r a d i a t i o n. T h e S E T R M co v e rs t he f o l l o w i n g: (1) A n ana l ys i s o f t he sta t us o f so la r ene r g y te c h n o l o g i es (glo ba l l y); (2) So u t h A f r i c a n st re n g t hs i n so la r ener g y tec h n o l o g i es; (3) A n ana l y s is o f l i n k a ges w i t h S o u t h A f r i c a n ene r g y an d c l i m a te c ha n ge p o l i c i es/st ra te g y, an d t he c u r r e n t ener g y c r i s i s; (4) D i r e c t i o n f o r ene r g y resea r c h ca pab i l i t y ; (5) A n assess me n t o f t he c o u n t r y ’s c o m p e t i t i v e ness i n so la r ene r g y te c h n o l o g i es; (6) a c l ea r l y a r t i c u l a te d an d peer-re v i e w e d p r i o r i t i z a t i o n p r o cess, c o re tec h n o l o g i es t o be de ve l o p e d o v e r t he ne x t 1 0 y ea rs (sp l i t i n t o a sh o r t, m e d i u m, an d l o n g te r m) w i t h c l ea r l y m e asu ra b l e o b j e c t i v es f o r eac h, sh o u l d t he n be se le c te d, an d t he asso c i a te d r o a d m a ps de ve l o p e d. T h e a t te n da n t reso u r ce

1 F i g u r es | C S I R


r e q u i r e me n ts a ls o need t o be est i m a te d; an d (7) a S W O T ana l ys i s an d asso c ia te d m i t i g a t i n g m easu res.


This is study, which is coordinated by the CSIR, is commissioned by the Department of Science and Technology

Main Authors

Alan Brent (Centre for Renewable and Sustainable Energy Studies, University of Stellenbosch) and Tinus (Graduate School of Technology Management

University of Pretoria)

Members of the Project

Wim Jonker Klunne, Thomas Roos, Steve Szeswuk, Monga Mehlwana, Pumza Zweni(all CSIR), Dieter Holm (ISES),Wikus van Niekerk (CRSES), Johann Basson (Independent)

C S I R r ef er en c e n um b er :

R D SE F S2/02600A l l r i g h t s to th e i n t e l l ec t u a l p r o p er t y an d /o r c o n ten t s o f th i s d o c um en t r em ai n v est ed i n th e C S I R . T h i s d o c um en t i s i n t en d ed so l e l y f o r u se b y th e D ep ar tm en t o f S c i en c e an d T ec h n o l o g y an d m ay n o t b e u sed , i n w h o l e o r i n p ar t , i n th e p r ep ar a t i o n o f sp ec i f i c a t i o n s f o r an y ten d er d o c um en t s o r ca l l s f o r q u o ta t i o n s an d / o r c o u n ter p r o p o sal s f r o m si m i l a r ser v i c e p r o v i d er s w i t h o u t th e ex p r ess w r i t t en p erm i ssi o n o f th e C S I R .B ase l i n e st u d yT ec h n o l o g y r o adm apF easi b i l i t y stu d i esB u si n ess p l anSteam and electricity generationSolar resource collection and conversionGovernmentI ndustry

R esearchI nstitutions

3 E X E C U T I V E S U M M A R Y | C S I R


E X ECUT I V ESU M M A R YT h e c o o r d i n a t i o n an d de v e l o p me n t o f a na t i o na l so l a r ene r g y te c h n o l o g y r oa d ma p (SE T R M), t h r o u g h a m u l t i-sta ke h o l d e r p r o cess, i s t he sec o n d c o m p o n e n t o f a l a r ge r p r o j e c t o f t he D e p a r t m e n t o f S c i e n ce an d Te c h n o l o g y (DS T) t o ena b le an e me r g i n g so la r ene r g y i n d us t r y i n t he c o u n t r y. T h e S E T R M p r i m a r i l y a i m s t o h i g h l i g h t k e y st ra te g i c resea r c h an d de ve l o p me n t (R& D) f o c us a reas, an d t he re q u i r e d i n te r v e n t i o n s b y v a r i o us r o l e p l a y e rs t o ena b l e suc h R & D ; t he g oa l o f t h e S E T R M is n o t t o p r o v i d e i n s i g h t i n te r ms o f w h e r e t he so la r ene r g y sec t o r o f S o u t h A f r i c a sh o u l d be hea d i n g, b u t w h e r e t he na t i o na l s ys te m o f i n n o v a t i o n (NS I) sh o u l d p l a ce i ts e m p has i s t o su p p o r t an d e x pa n d t he e me r g i n g i n d us t r y. T h e S E T R M de ve l o p me n t p r o cess c o ns is te d o f:

• B o t t o m-u p da ta ga t he r i n g t h r o u g h d i r e c t c o ns u l ta t i o n w i t h sta ke h o l d e rs b y ca r r y i n g o u t o ne-o n-o ne i n t e r v i e w s w i t h resea r c he rs i n t he na t i o na l s ys te m o f i n n o v a t i o n (NS I), an d i n d us t r y, an d u t i l i s i n g m a te r i a l o b t a i ne d f r o m v a r i o u s S o u t h A f r i c a n w o r k s h o ps an d t he S o l a r W o r l d C o n g r ess 2009, ab o u t o p p o r t u n i t i es an d c o ns t ra i n ts f a c i n g ac t i v e so la r ene r g y te c h n o l o g i es;

• D e s k t o p resea r c h i n o r de r t o c o l l e c t an d re v i e w re le v a n t na t i o na l an d i n t e r n a t i o na l p u b l i c a t i o ns an d t he o u t p u ts o f s i m i l a r r oa d ma p p i n g e xe r c i ses e lse w h e re;

• A n a l y s i n g t he c o l l e c te d da ta t o assess t he m a r k e t, i n d u s t r y-de v e l o p m e n t an d te c h n o l o g y de ve l o p me n t p o te n t i a l i n S o u t h A f r i c a;

• D r a f t i n g t he r oa d ma p d o c u m e n t, an d tes t i n g i t an d t he ana l y ses be h i n d i t, b y c i r c u l a t i n g i t t o sta ke h o l d e rs i n t he N S I , i n d us t r y an d g o v e r n m e n t, f o r c r i t i q u e an d c o m m e n ts; an d

• F i n a l i s i n g t he r oa d ma p d o c u me n t a f te r a w o r k s h o p en ga ge me n t w i t h d i f f e re n t sta ke h o l d e rs d u r i n g F e b r ua r y 20 10.

T h e S E T R M f o c u ses o n t he ge ne r i c te c h n o l o g y p l a t f o r m s pe r ta i n i n g t o power an d thermal as ene r g y se r v i c es; t hese p l a t f o r m s a re su m ma r i se d be l o w :

System service System market / application System output Generic technology platforms

Power

S i n g u l a r h o useh o l ds S m a l l < 5 k W C o n v e n t i o n a l w i t h o u t t r a c k i n g p h o t o v o l t a i c

M i n i o f f-g r i d f o r sma l l c o m m u n i t i es

M e d i u m

< 500 k W

C o n v e n t i o n a l o r t h i n f i l m w i t h / w i t h o u t t r a c k i n g, o r c o n c en t r a t e d p h o t o v o l t a i c

C o m m e r c i a l b u i l d i n gs / A g r i c u l t u r e sec t o r < 1 M WC o n v e n t i o n a l o r t h i n f i l m w i t h / w i t h o u t t r a c k i n g, o r c o n c en t r a t e d p h o t o v o l t a i c

I n d u s t r y sec t o r

L a r g e

> 1 M WC o n ce n t r a t e d o r t h i n f i l m p h o t o v o l t a i c w i t h t r a c k i n g

C o n ce n t r a t e d (ther ma l) p o w e r

M u n i c i p a l i t i es / c o m m e r c i a l c l us te rs > 1 M WC o n ce n t r a t e d o r t h i n f i l m p h o t o v o l t a i c w i t h t r a c k i n g / pa r ks

C o n ce n t r a t e d (ther ma l) p o w e r

N a t i o n a l g r i d > 1 0 M WC o n ce n t r a t e d o r t h i n f i l m p h o t o v o l t a i c w i t h t r a c k i n g / pa r ks

C o n ce n t r a t e d (ther ma l) p o w e r / pa r ks




Thermal

S i n g u l a r h o useh o l ds / c o m m u n i t i es f o r w a t e r an d space hea t i n g

L o w

< 80º C N o n-t r a c k i n g c o l l e c t o r s

S i n g u l a r h o useh o l ds / c o m m u n i t i es f o r c o o k i n g

< 1 00º C N o n-t r a c k i n g o r m a n ua l t r a c k i n g c o l l e c t o r s

C o m m e r c i a l b u i l d i n gs / A g r i c u l t u r e sec t o r f o r c o o l i n g (adso r p t i o n c h i l l e r s)

60 - 90º C N o n-t r a c k i n g c o l l e c t o r s

C o m m e r c i a l b u i l d i n gs / A g r i c u l t u r e sec t o r f o r c o o l i n g (adso r p t i o n c h i l l e r s, s i n g l e an d d o u b l e ac t i o n)

75 - 1 1 5º C

N o n-t r a c k i n g c o l l e c t o r s

M u n i c i p a l i t i es / c o m m e r c i a l c l us te rs / i n d us t r y sec t o r f o r m u l t i e f f e c t desa l i n a t i o n (ME D)

< 70º C N o n-t r a c k i n g c o l l e c t o r s

M u n i c i p a l i t i es / c o m m e r c i a l c l us te rs / i n d us t r y sec t o r f o r desa l i n a t i o n b y m e m b r a ne d i s t i l l a t i o n

90 - 1 00º C

N o n-t r a c k i n g c o l l e c t o r s

C o m m e r c i a l b u i l d i n gs / A g r i c u l t u r e sec t o r / i n d us t r y sec t o r f o r c o o l i n g (adso r p t i o n c h i l l e rs, s i n g l e an d d o u b l e ac t i o n)

M e d i u m

1 30 - 1 80º C

C o n ce n t r a t e d t he r m a l w i t h t r a c k i n g, spe c i f i c a l l y w i t h a s i m p l e pa ra b o l i c t r o u g h

M u n i c i p a l i t i es / c o m m e r c i a l c l us te rs / i n d us t r y sec t o r f o r desa l i n a t i o n b y m u l t i stage f l as h (MS F) d i s t i l l a t i o n

90 - 1 20º C

N o n-t r a c k i n g c o l l e c t o r s, o r c o n ce n t r a t e d t he r m a l w i t h t r a c k i n g, spe c i f i c a l l y w i t h s i m p l e pa ra b o l i c t r o u g h

I n d u s t r y sec t o r f o r p r o cess hea t < 250º CC o n ce n t r a t e d t he r m a l w i t h t r a c k i n g, spe c i f i c a l l y w i t h pa ra b o l i c t r o u g h an d l i n ea r F r es ne l

I n d u s t r y sec t o r f o r p r o cess hea t

H i g h

< 400º CC o n ce n t r a t e d t he r m a l w i t h t r a c k i n g, spe c i f i c a l l y w i t h a ad va n ce d pa ra b o l i c t r o u g h an d l i n ea r F r es ne l

I n d u s t r y sec t o r f o r t he r m o c he m i s t r y an d f u e l s

> 750º CC o n ce n t r a t e d t he r m a l w i t h t r a c k i n g, spe c i f i c a l l y w i t h a cen t r a l re ce i v e r

S t re n g t h, w ea k n ess, o p p o r t u n i t y an d t h rea t (SW O T) ana l y ses w e r e c o n d u c te d f o r t he d i f f e re n t ap p l i c a t i o n s an d te c h n o l o g i c a l s ys te ms i n t he S o u t h A f r i c a n N S I, as w e l l as a m a r k e t r ea d i n ess ana l y s i s o f t h e d i f f e r e n t te c h n o l o g i c a l s ys te ms based o n c u r r e n t i n te r na t i o na l ad va n ces i n t he te c h n o l o g i ca l s ys te ms, t he i n t e r na t i o na l m a r k e t t re n ds an d d r i v e rs, an d t he S o u t h A f r i c a n m a r k e t p o te n t i a l an d ba r r i e rs t ha t m a y be ad d ressed t h r o u g h R & D . T h e ana l y ses re v ea le d t he R & D re q u i r e m e n ts o f t h e d i f f e re n t te c h n o l o g i es, as w e l l as t he re q u i r e me n ts o f t h ose te c h n o l o g i es t ha t ha ve bee n de m o ns t ra te d, w h i c h nee d t o be c o m me r c i a l i se d i n S o u t h A f r i c a, an d t h ose t ha t a re a l read y c o m m e r c i a l i se d an d ca n t he re f o r e be ac q u i r e d d i re c t l y ; t he re q u i r e m e n ts a re su m m a r i se d i n t he ta b le be l o w. T h o se te c h n o l o g i c a l p l a t f o r m s t ha t a re i n t he de m o ns t ra te d an d c o m m e r c ia l i se d l i f e c y c l e p hase w e re t he n f u r t h e r ana l y sed i n te r ms o f :

• G o v e r n m e n t i n t e ns i t y i n te r ms o f t he re q u i r e m e n t f o r t h ose te c h n o l o g i c a l p l a t f o r m s t ha t w o u l d st i m u l a te ec o n o m i c g r o w t h c o u p l e d w i t h i n d u s t r y de ve l o p me n t an d e m p l o y m e n t c r ea t i o n, t h ose t ha t w o u l d i m p r o v e ene r g y sec u r i t y an d ac cess, an d t h ose t ha t w o u l d ad d ress c l i m a t e c ha n ge;

• I n d u s t r y i n te ns i t y i n te r ms o f t h ose te c h n o l o g i c a l p l a t f o r m s t ha t c o u l d e x pa n d a l o ca l su p p l y c ha i n, an d l ea d t o a g r ea te r e x p o r t p o t e n t i a l o f p r o d u c ts, te c h n o l o g i es an d k n o w l e d ge; an d

• R & D i n t e ns i t y i n te r ms o f a va i l a b l e ca pac i t y an d asso c ia te res o u r ces nee de d t o su p p o r t t he f u r t h e r de ve l o p me n t o f t h e te c h n o l o g i c a l p l a t f o r m s.

T h e ana l y s i s i s su m ma r i sed i n t he f i g u r e be l o w t he ta b le.



√ Denotes the life cycle phase that characterises the technological system internationally

Technological system

R & D(primarily D ST)

Demonstrated(primarily DoE)

Commercialised(private sector)

Possible driver organisations

Power – P hotovoltaic

C o n v e n t i o n a l • R & D f o c us o n

c ha r ac te r i sa t i o n o f se m i c o n d u c t o r s.

• D e v e l o p m e n t o f

ap p r o p r i a t e ed u ca t i o n an d t r a i n i n g p r o g r a m m es.

• E s t a b l i s h R & D f a c i l i t i es

f o r i m p r o v e d an d ne w ge ne r a t i o n st o r a ge tec h n o l o g i es.

• O p t i m i se o p t i ca l s ys te m

tec h n o l o g i es f o r p r o d u c t an d m a n u f a c t u r i n g.

• E x p a ns i o n o f e x i s t i n g

s ys te m des i g n, s i m u l a t i o n an d o p t i m i sa t i o n capa b i l i t i es, i n c l u d i n g pa ne l, st r u c t u r e an d t r ac k i n g s ys te ms.

√

E x i s t i n g i n d us t r y, l o c a l an d g l o b a l.

C o n ce n t r a t e d √

T h i n f i l m • E x pa ns i o n o f f a c i l i t i es

f o r R & D o n l o w c os t an d h i g h e f f i c i e n c y t h i n f i l m p r o d u c t s.

• E x pa ns i o n o f e x i s t i n g

c ha r ac te r i sa t i o n an d tes t i n g capa b i l i t i es.

• R & D t o o p t i m i se

m a n u f a c t u r i n g tec h n o l o g i es.

√

Saso l,

C E F,

T h i n F i l m S o l a r Te c h n o l o g i es,

O t h e r s g l o b a l l y.

Concentrated solar power

Pa ra b o l i c t r o u g h • E x pa ns i o n o f e x i s t i n g

s ys te m des i g n, s i m u l a t i o n an d o p t i m i sa t i o n ca pab i l i t i es, i n c l u d i n g st r u c t u r e an d t r ac k i n g s ys te ms, an d d r y c o o l i n g f o r t he p o w e r b l o c k.




f o r i m p r o v e d an d ne w ge ne r a t i o n abs o r be r an d st o r a ge tec h n o l o g i es.

• O p t i m i se r ece i v e r

s ys te m tec h n o l o g i es f o r p r o d u c t s an d m a n u f a c t u r i n g

√

M i n i n g h o uses an d o t he r c o m pa n i es w i t h l a r ge f a c i l i t i es / p l a n t s.



√ Denotes the life cycle phase that characterises the technological system internationally






C e n t r a l r ece i v e r s • O p t i m i se re ce i v e r

s ys te m tec h n o l o g i es f o r p r o d u c t s an d m a n u f a c t u r i n g.


s ys te m des i g n, s i m u l a t i o n an d o p t i m i sa t i o n ca pab i l i t i es, i n c l u d i n g st r u c t u r e an d he l i o s t a t s ys te ms, an d d r y c o o l i n g f o r t he p o w e r b l o c k.





√

Es k o m, S K A (Meer K a t), so l a r pa r k s.

L i n ea r F r es ne l • A s w i t h pa ra b o l i c

t r o u g h √

I n d us t r i a l p l a n t s, c o m m e r c i a l b u i l d i n gs, o f f-g r i d use rs.

D i s h S t i r l i n g √ R & D i ns t i t u t i o ns, c o m m e r c i a l b u i l d i n gs.

Thermal

N o n-t ra c k i n g c o l l e c t o r s

• N o n e en v i sa ge dS y s te m o p t i m i sa t i o n resear c h p r o j e c t s

√ N e w D o E f r a m e w o r k.

C o n ce n t r a t e d w i t h t r a c k i n g

• A s w i t h pa ra b o l i c

t r o u g h an d l i n ea r F r es ne l w i t h o u t t he p o w e r b l o c k

√

I n d us t r i a l p l a n t s an d ag r i c u l t u r e.

Other

R eso u r ce assess me n t an d m a p p i n g

• R esea r c h f o c us o n

m easu r e m e n t an d da ta ana l y s i s

E s ta b l i s h de d i ca te d reso u r ce assess me n t i ns t i t u t i o n/s √

G o v e r n m e n t,

E s k o m, l a r ge c o m pa n i es.

S t a n da r ds an d test i n g • D e v e l o p m e n t o f q ua l i t y

tes t i n g capa b i l i t i es√

G o v e r n m e n t, m a n u f a c t u r i n g i n d us t r y.

T h e ana l y s i s i n t he f i g u r e g u i d es t he S E T R M i m p l e me n ta t i o n o v e r t he ne x t f i v e y ea rs, w h i l s t t he R & D re q u i r e m e n ts an d t he te c h n o l o g y s ys te ms i n t he R & D l i f e c y c l e p hase o f t he ta b l e g u i d e t he S E T R M i m p l e me n ta t i o n o v e r t he ne x t te n y ea rs.

Next five years – the short term

T h e S E T R M h i g h l i g h ts e i g h t te c h n o l o g i ca l s ys te ms t ha t ha v e c lea r l y bee n de m o ns t ra te d o r c o m m e r c i a l i se d, w h e r e a l o ca l i n d us t r y c o u l d be st i m u l a te d (w i t h t he p o t e n t i a l o f e x p o r t o p p o r t u n i t i es) an d t he o t he r re q u i r e m e n ts o f g o v e r n me n t ca n be m e t, an d t ha t ha ve a m e d i u m t o h i g h R & D i n t e ns i t y :



• P V s ys te ms (con ce n t ra te d an d t h i n f i l m) w i t h st o ra ge f o r l ess t ha n 500 k W p o w e r su p p l y, t y p i c a l l y f o r o f f-g r i d an d c o m m e r c i a l b u i l d i n g ap p l i c a t i o n s;

• P V s ys te ms (con ce n t ra te d an d t h i n f i l m) w i t h o u t s t o ra ge f o r m o r e t ha n 1 M W g r i d-c o n nec te d p o w e r su p p l y ;

• C SP s ys te ms (parab o l i c t r o u g h, l i n ea r F r es ne l an d ce n t ra l re ce i v e r) w i t h o u t s t o ra ge f o r l ess t ha n 1 0 M W g r i d-c o n ne c te d p o w e r su p p l y ;

• C SP s ys te ms (parab o l i c t r o u g h an d ce n t ra l re ce i v e r) w i t h st o ra ge f o r m o r e t ha n 50 M W g r i d-c o n ne c te d p o w e r su p p l y ;

• So l a r hea t i n g s ys te ms (non-t ra c k i n g an d s i m p l e pa ra b o l i c t r o u g h) f o r p r o cess hea t o f l ess t ha n 1 50º C;

• So l a r hea t i n g s ys te ms (parab o l i c t r o u g h an d l i n ea r F r esne l) f o r p r o cess hea t o f l ess t ha n 250º C;

• So l a r hea t i n g s ys te ms (ad va n ce d pa ra b o l i c t r o u g h an d l i n ea r F r es ne l) f o r p r o cess hea t o f f l ess t ha n 400º C; an d

• So l a r hea t i n g s ys te ms (cent ra l re ce i v e r) f o r t h e r m o c he m i s t r y hea t o f m o r e t ha n 750º C.

F u r t h e r m o r e, res o u r ce m a p p i n g i s re q u i r e d i n t he sh o r t te r m an d sta n da r ds an d tes t i n g f a c i l i t i es nee d t o be esta b l i s h e d an d su p p o r te d, n o t o n l y f o r t h e e i g h t p r i o r i t i se d te c h n o l o g i c a l s ys te ms, b u t a ls o f o r t h ose t ha t ha ve a l read y bee n c o m m e r c i a l i se d an d re q u i r e l ess R & D i n t e r v e n t i o ns.

Next ten years – the short to medium term

I n t h e sh o r t t o m e d i u m te r m R & D res o u r ces nee d t o be d i r e c te d o n a c o n t i n ua l bas is t o su p p o r t t he f o u r p r i o r i t i se d an d o t he r te c h n o l o g i c a l s ys te ms t ha t a re i n t he c o m me r c i a l i sa t i o n p hase:

• C o n v e n t i o na l an d c o n ce n t ra te d P V s ys te ms f o r p o w e r ap p l i ca t i o ns: R & D f o c us o n t he c ha ra c te r isa t i o n o f se m i c o n d u c t o r s; de ve l o p me n t o f ap p r o p r i a te ed u ca t i o n an d t ra i n i n g p r o g r a m m es; an d esta b l i s h i n g R & D f a c i l i t i es f o r i m p r o v e d an d ne w ge ne ra t i o n st o ra ge te c h n o l o g i es.

• T h i n f i l m P V s ys te ms f o r p o w e r ap p l i c a t i o n s: E x p a ns i o n o f f a c i l i t i es f o r R & D o n l o w c os t an d h i g h e f f i c i e n c y t h i n f i l m p r o d u c ts; e x pa ns i o n o f e x i s t i n g c ha ra c te r isa t i o n an d tes t i n g ca pa b i l i t i es; an d R & D t o o p t i m i se m a n u f a c t u r i n g te c h n o l o g i es.

• C SP s ys te ms f o r p o w e r an d t he r m a l ap p l i ca t i o ns: O p t i m i se re ce i v e r s ys te m te c h n o l o g i es f o r p r o d u c ts an d m a n u f a c t u r i n g (cent ra l re ce i v e rs); e x pa ns i o n o f e x i s t i n g s ys te m des i g n, s i m u l a t i o n an d o p t i m i sa t i o n ca pa b i l i t i es, i n c l u d i n g r e ce i v e r s t r u c t u r e an d t ra c k i n g s ys te ms, an d d r y an d h y b r i d c o o l i n g i n t he p o w e r b l o c k; de v e l o p m e n t o f ap p r o p r i a te ed u ca t i o n an d t ra i n i n g p r o g r a m m es; an d esta b l i s h i n g R & D f a c i l i t i es f o r i m p r o v e d an d ne w ge ne ra t i o n abs o r be r an d st o ra ge te c h n o l o g i es.

• T h e r m a l ap p l i c a t i o n s: S ys te m o p t i m i sa t i o n resea r c h p r o j e c ts f o r spec i f i c ap p l i ca t i o ns, espec i a l l y f o r p r o cess hea t w h e r e a s i g n i f i c a n t c o n t r i b u t i o n ca n be m a de.

O t h e r aspec ts t o c o ns i d e r i n c l u de: so la r r esea r c h pa r k s; ce n t res o f e x ce l l e n ce; u n i v e rs i t y c ha i rs; spec i f i c o u t-c o n t ra c te d p r o j e c ts b y D S T an d D o E; an d ge ne ra l ed u ca t i o n an d t ra i n i n g p r o g ra m m es.

T h e p r o p ose d f i v e an d te n y ea r ac t i v i t i es w e r e re v i e w e d an d be n c h m a r k e d aga i ns t t he o u t c o mes o f t w o w o r k s h o ps; t he f i r s t a C SP W o r k s h o p he l d o n 1 1 D e ce m be r 2009, an d a sec o n d w o r k s h o p o n 1 9 Fe b r ua r y 20 10 w h e r e sta ke h o l d e rs i n t he so l a r ene r g y f i e l d (go ve r n m e n t, i n d us t r y an d t he resea r c h i n s t i t u t i o ns) he l d a st ra te g i c c o n v e rsa t i o n ab o u t t h e p r o p ose d S E T R M . T h ese w o r k s h o ps a re d o c u me n te d i n sepa ra te re p o r ts.

F r o m an e va l u a t i o n o f t he c o m pa r i s o ns o f t he v a r i o u s o u t c o m es o f t h e p r o p ose d S E T R M an d t he W o r k s h o ps, f i v e de f i n i t i v e so la r te c h n o l o g y s ys te m f o c us a reas ca n be i de n t i f i e d, na me l y :

1 . S o l a r R es o u r ce A s sess me n t;2. P h o t o v o l t a i c S ys te ms;3. C o n ce n t ra te d S o l a r P o w e r;4. I n d u s t r i a l S o l a r H e a t i n g an d C o o l i n g; an d5. N a t i o na l c o o r d i n a t i o n an d c o l l a b o r a t i v e de m o ns t ra t i o n f a c i l i t i es.



F o r p ra c t i c a l i m p l e me n ta t i o n o f t he S E T R M i t i s su g ges te d t ha t a st r u c t u re o r s t r u c t u r es a re c rea te d t o ac c o m m o da te t he v a r i o us ac t i v i t i es o f t h e S E T R M w i t h i n t hese te c h n o l o g y s ys te m f o c u s a reas



A B B R E V I AT I O NS

a-S i A m o r p h o us s i l i c o n

B I P V B u i l d i n g-i n te g r a te d P V

B O S B a l a n ce-o f-S ys te m

B S R B l a c k S u r f a ce R e f l e c ta n ce

C D M C l ea n D e v e l o p m e n t M e c h a n i s m

C d Te C a d m i u m te l l u r i d e

C H P C o m b i n e d hea t an d p o w e r

C I S C o p pe r i n d i u m se le n i d e

C I G S C o p pe r i n d i u m ga l l i u m se le n i d e

C L F R C o m p a c t L i n ea r F r es ne l R e f l e c t o r

C O P C oe f f i c i e n t o f pe r f o r m a n ce

C P C C o m p o u n d Pa ra b o l i c C o l l e c t o r

C P V C o n ce n t ra te d p h o t o v o l ta i c

C R S C e n t ra l re ce i v e r s ys te ms

C R S E S C e n t re f o r R e ne w a b l e an d S us ta i na b le E ne r g y S t u d i es

c-S i C r y s ta l l i n e s i l i c o n

C S I R C o u n c i l f o r S c i e n t i f i c an d I n d us t r i a l R esea r c h

C S P C o n ce n t ra te d S o l a r P o w e r

C S T C o n ce n t ra te d S o l a r T h e r m a l

C T F C l ea n te c h n o l o g y f u n d

D I R D i r e c t so la r ra d i a t i o n

D N I D i r e c t n o r m a l i r r a d ia n ce

D o E D e pa r t m e n t o f E n e r g y

D S D i s h S t i r l i n g

D S C D y e-sens i t i se d so la r ce l l

D S T D e p a r t m e n t o f S c i e n ce an d Te c h n o l o g y

D W H D o m es t i c W a te r H ea t i n g

E R C E ne r g y R esea r c h C e n t re

G H I G l o b a l h o r i z o n t a l i r r a d i a n ce

G S T M G r a d ua te Sc h o o l o f Te c h n o l o g y M a n a ge me n t

H C E H ea t c o l l e c t i n g e le me n ts

H T F H ea t t ra ns fe r f l u i d

H T S T H i g h te m pe ra t u re so la r t he r m a l

H X H ea t e x c ha n ge r

I R E N A I n t e r n a t i o na l R e ne w a b l e E ne r g y A g e n c y

L C Z L o w e r c o n v e c t i v e z o ne

L E C L e v e l i se d e le c t r i c i t y c os t

L F L i n ea r F r es ne l

L F R L i n ea r F r es ne l R e f l e c t o r

-S iμ M i c r o c r y s ta l l i n e S i l i c o n

N C Z N o n-c o n v e c t i v e z o ne

N E R S A N a t i o na l E n e r g y R e g u l a t o r o f S o u t h A f r i c a

N M M U N e l s o n M a n d e l a M e t r o p o l i t a n U n i v e rs i t y

N S I N a t i o na l S ys te m o f I n n o v a t i o n

p C D M P r o g r a m m a t i c C l ea n D e v e l o p me n t M e c h a n i s m

P C M Phase C h a n ge M a t e r i a l s

P C U Po w e r c o n v e rs i o n u n i t

PP A P u r c hase p o w e r ag ree me n t

P T Pa ra b o l i c t r o u g h

P V P h o t o v o l t a i c

R E F I T R e ne w a b l e ene r g y f ee d-i n ta r i f f

R E T R e ne w a b l e ene r g y te c h n o l o g y

R O E U R e m o te l y o pe ra b le e le c t r i ca l u m b i l i c a l

S A D C So u t he r n A f r i c a n D e v e l o p me n t C o m m u n i t y

S A N E R I S o u t h A f r i c a n N a t i o na l E n e r g y R esea r c h I n s t i t u te

S A N E D I S o u t h A f r i c a n N a t i o na l E n e r g y D e v e l o p me n t I n s t i t u te

S E T R M So l a r E n e r g y Te c h n o l o g y R oa d m a p

S H I P S o l a r hea t f o r i n d u s t r i a l p r o cesses

S W H So l a r w a te r hea t i n g

S U S te l l e n b os c h U n i v e rs i t y

T C O T r a ns pa re n t c o n d u c t i v e o x i d es

T F S T T h i n F i l m S o l a r Te c h n o l o g y

T I M T r a ns pa re n t i n s u la t i o n m a te r i a ls

T P V T h e r m o p h o t o v o l t a i c

T R M Te c h n o l o g y R oa d m a p

U C Z U p pe r c o n v e c t i v e z o ne

U C T U n i v e rs i t y o f C a pe T o w n

U F H U n i v e rs i t y o f F o r t H a r e

U P U n i v e rs i t y o f P re t o r i a

W W a t t

W P W a t t pea k

W e W a t t e le c t r i c i t y

W t h W a t t t he r m a l

L T I L a t i t u de t i l t i r r a d i a n ce

1 0 F i g u r es | C S I R


TA B L E OF CONT E NTSE X ECUT I V E S U M M A RY .....................................................................................3

Abbreviations...................................................................................................8

Table of Contents..............................................................................................9

Figures..........................................................................................................10

Tables............................................................................................................11

1. I ntroduction...............................................................................................121.Background...........................................................................122.Focus of this solar energy technology roadmap.......................123. Methodology..........................................................................19

2. Active Solar E nergy Technology S ystems......................................................191.Power applications................................................................19

1.1.Photoelectric systems.....................................................................................201.1.1.Conventional photovoltaic...........................................................................201.1.2.Concentrating photovoltaic..........................................................................201.1.3.Thin film photovoltaic...............................................................................201.1.4.Photovoltaic manufacturing research...............................................................21

1.2.Concentrated solar power systems.......................................................................231.2.1.Parabolic troughs....................................................................................251.2.2.Central receivers.....................................................................................251.2.3.Linear Fresnel.......................................................................................261.2.4.Dish Stirling..........................................................................................261.2.5.CSP manufacturing research........................................................................26

1.3.Non-concentrating solar thermal systems................................................................281.3.1.Solar chimney........................................................................................281.3.2.Solar ponds...........................................................................................28

2.Thermal heating and cooling applications...............................292.1.Non-tracking, improved flat plate collectors.............................................................30

2.1.1.Optical losses........................................................................................302.1.2.Thermal losses.......................................................................................302.1.3.Construction principle...............................................................................302.1.4.Current stage of development........................................................................30

2.2.Evacuated tube collectors................................................................................312.2.1.Direct flow evacuated tube collectors...............................................................312.2.2.Heat pipe evacuated tube collectors.................................................................312.2.3.Current stage of development........................................................................32

2.3.Concentrating flat plate collectors.......................................................................322.3.1.Low concentration...................................................................................322.3.2.High concentration..................................................................................32

2.4.Concentrating collectors with tracking...................................................................322.4.1.Small parabolic trough collectors...................................................................322.4.2.Linear Fresnel collectors............................................................................332.4.3.Solar thermochemistry...............................................................................33

3. International m arket trends and drivers, and cost implications 344.Power applications................................................................34



4.1.PV systems – trends.......................................................................................344.2.PV systems – drivers......................................................................................354.3.CSP systems – trends.....................................................................................354.4.CSP systems – drivers....................................................................................364.5.Solar chimney.............................................................................................394.6.Solar ponds................................................................................................39

5.Thermal heating and cooling applications...............................395.1.General trends and drivers...............................................................................395.2.Trends and drivers for industrial applications...........................................................40

6.The international policy landscape.........................................413. South African M arket Potential and B arriers................................................41

1.Role of active solar systems....................................................422.Power applications................................................................42

2.1.PV systems – market potential............................................................................422.2.PV systems – market barriers.............................................................................452.3.CSP systems – market potential..........................................................................452.4.CSP systems – market barriers...........................................................................462.5.Solar chimney.............................................................................................46

3.Thermal heating and cooling applications...............................463.1.General potential and barriers...........................................................................463.2.Potential for industrial applications......................................................................48

4.Assessing the potential for active solar systems........................484. Strategic A nalysis for Research in South Africa............................................48

1.South African National S ystem of I n novation..........................482.Power applications................................................................49

2.1.PV systems................................................................................................492.2.CSP systems...............................................................................................51

3.Thermal heating and cooling applications...............................525. The S ET R M for South Africa.......................................................................52

1.R & D vision............................................................................522.R & D strategies......................................................................52

2.1.R&D funding..............................................................................................522.2.R&D and other priorities.................................................................................53

3.R & D implementation.............................................................533.1.Short term – next five years...............................................................................533.2.Short to medium term – next ten years...................................................................54

4.Review of the R & D strategies.................................................544.1.Outcomes of the CSP Workshop: 11 December 2009....................................................544.2.Outcomes of the SETRM Workshop: 19 February 2010.................................................54

6. References..................................................................................................55

Appendix A – C S P value chain.........................................................................59

Appendix B –participants of the S ET R M workshop of 19 February 2010............60



FI GU R E S



TA B L E S


1. I NT R O DUCT IO N

1. B ackgroundSo u t h A f r i c a has t he m a j o r c ha l l e n ge o f c l os i n g t he ga p be t w ee n i t s f i r s t (deve l o pe d) an d sec o n d (deve l o p i n g) ec o n o m i es, w h i l e ‘ de c o u p l i n g’ t h e g r o w t h o f t h e ec o n o m y as a w h o l e, na me l y m a i n t a i n i n g t he g r o w t h w i t h de c l i n i n g m a te r i a l t h r o u g h p u t (see F i g u re 1 , an d w i t h asso c i a te d be ne f i t s su c h as i m p r o v i n g t he ca r b o n e m i ss i o ns ba l a n ce o f t he ec o n o m y (Bren t e t a l., 2009). F u r t he r, t o be g l o ba l l y c o m p e t i t i v e, an d t o m a k e t he t ra ns i t i o n t o w a r d s a k n o w l e d ge-base d ec o n o m y, w i l l re q u i r e i n n o v a t i o n f o r sus ta i n a b i l i t y an d asso c ia te d i n n o v a t i v e de v e l o p m e n t s t ra te g ies.

T h e su p p o r t o f ap p r o p r i a te te c h n o l o g y r esea r c h an d de ve l o p m e n t (R& D) is c o r e t o suc h st ra te g i es. T o t h i s en d t he S o u t h A f r i c a n na t i o na l D e pa r t m e n t o f S c i e n ce an d Te c h n o l o g y (DS T) has re c o g n i se d t he nee d t o ena b l e an e me r g i n g so la r ene r g y i n d u s t r y, w h i c h ca n ad d ress t he c ha l l e n ge, an d a ls o c o n t r i b u t e t o ene r g y reso u r ces d i v e rs i f i c a t i o n i n t he c o u n t r y. T h e res p o nse has bee n a na t i o na l p r o j e c t, f a c i l i t a te d b y t he S o u t h A f r i c a n C o u n c i l f o r S c i e n t i f i c an d I n d us t r i a l R esea r c h (CS I R), w i t h a n u m b e r o f c o m p o ne n ts (see F i g u r e 1 .2).

Figure : Representation of “Upstream” and “ Downstream” decoupling (Source: UNE P, 2009)

Figure : Overview of the components of the D ST solar energy project

T h i s st u d y de ve l o ps a na t i o na l so la r ene r g y te c h n o l o g y r oa d ma p (SE T R M) t h r o u g h a m u l t i-s ta ke h o l d e r p r o cess. I t a i m s t o h i g h l i g h t k e y st ra te g i c resea r c h f o c u s a reas, t he re q u i r e d i n te r v e n t i o n s b y v a r i o us r o l e p l a y e rs t o ena b l e suc h resea r c h, an d, i n ge ne ra l, h o w bes t S o u t h A f r i c a m a y esta b l i s h an i n d u s t r y t ha t uses i ts c o m pa r a t i v e

ad v a n ta ge o f so la r i r r a d i a t i o n (see F i g u r e 3); t he S o u t h A f r i c a n so la r res o u r ce i s u p t o o ne-t h i r d be t te r t h a n t ha t o f S pa i n w h e r e m o s t ne w so la r p o w e r sta t i o ns a re c u r re n t l y be i n g b u i l t. T h e r oa d ma p w i l l i n te ra c t w i t h t he o t he r c o m p o ne n ts o f t he o v e ra l l p r o j e c t an d be u p da te d acc o r d i n g l y o v e r t i m e.

Figure : Average daily direct normal irradiation ( D N I ) for Africa and South AfricaSources: N R E L, 2005; Fluri, 2009)

2. Focus of this solar energy technology roadmapSo l a r c o l l e c t i o n te c h n o l o g i es, as pa r t o f so la r ene r g y s ys te ms, ca n be d i v i d e d i n t o t w o b r oa d ca te g o r i es: t h ose t ha t c o l l e c t l i g h t, an d t h ose t ha t c o l l e c t hea t. L i g h t i s use d f o r e le c t r i c i t y ge ne ra t i o n; de t o x i f i c a t i o n, t y p i c a l l y o f w a te r; an d i l l u m i n a t i o n. H e a t i s use d f o r d o m es t i c w a te r hea t i n g (D W H); c o o k i n g; p r o cess hea t, i n c l u d i n g abso r p t i o n c h i l l i n g an d t he r m a l desa l i n a t i o n; e le c t r i c i t y ge ne ra t i o n an d t he r m o c he m i s t r y. A f u r t h e r su b d i v i s i o n i s w h e t he r t he c o l l e c t i o n te c h n o l o g y m a kes use o f t ra c k i n g an d/or c o n ce n t ra t i o n. N o t a l l c o n ce n t ra t i n g te c h n o l o g i es m a k e use o f t ra c k i n g; e xa m p l es a re c o m p o u n d pa ra b o l i c c o l l e c t o r (CPC) t r o u g hs use d i n c o n ce n t ra te d p h o t o v o l ta i c (PV) and de t o x i f i c a t i o n s ys te ms. A l s o, n o t a l l te c h n o l o g i es t ha t t ra c k t he su n e m p l o y c o n ce n t ra t i o n; an e xa m p l e i s n o n-c o n ce n t ra t i n g, t ra c k i n g P V s ys te ms. T h i s i s i l l u s t r a te d i n Ta b l e. 1.

Table : Solar energy collection technologies

Energy used Application Technology system / family

Collection technology Concentrating Tracking

Light E l e c t r i c i t y

P V

M o n o c r ys t a l l i n e B o t h B o t h

T h i n-f i l m N N

M u l t i-j u n c t i o n N N

D y e ce l l D y e ce l l N N

D e t o x i f i c a t i o nP h o t o-ca ta l y s i s

T r a ns pa re n t p h o t o ca ta l y t i c reac t o r s

B o t h N

I l l u m i n a t i o nD a y l i g h t i n g

L i g h t t u bes N N

he l i o s t a t N Y

P h os f o r esce n ce P h os f o r esce n ce N N

O p t i ca l f i b r e O p t i ca l f i b r e Y Y

Heat D W H / l o w te m pe ra t u r e i n d us t r i a l h ea t

F l a t p l a t e F l a t p l a te N N

C P CC o n ce n t r a t e d pa ra b o l i c c o l l e c t o r

Y N

E v a c ua te d t u beD e w a r t u be N N

H e a t p i p e N N

C o o k i n g B o x N N

D i s h Y N

P r o cess / I n d us t r i a l L i n e f o c us Pa ra b o l i c t r o u g h Y Y

Energy used Application Technology system / family

Collection technology Concentrating Tracking

hea t c o n c en t r a t o r s L i n ea r F r es ne l Y Y

E l e c t r i c i t yN o n c o n c en t r a t i n g

S o l a r c h i m ne y N N

S o l a r p o n ds N N

L i n e f o c us c o n c en t r a t i o n

Pa ra b o l i c t r o u g h Y Y

L i n ea r F r es ne l Y Y

P o i n t f o c us c o n c en t r a t i o n

H e l i o s t a t f i e l d Y Y

D i s h Y Y

T h e r m o-c he m i s t r yP o i n t f o c us c o n c en t r a t i o n

H e l i o s t a t f i e l d Y Y

D i s h Y Y

T h e S E T R M spec i f i c a l l y f o c u ses o n ac t i v e so la r ene r g y s ys te ms 1 , an d e x c l u des pass i v e so l a r ene r g y s ys te ms 2. T h e p r i m a r y c lass i f i c a t i o n b r ea k d o w n o f t he ac t i v e so la r s ys te ms a re su m m a r i se d i n Ta b l e2, i n te r ms o f p o w e r an d t he r m a l as ene r g y se r v i c es, an d i n c l u d i n g sca le o r te m pe ra t u r e r a n ges. W h i l e Ta b l e 1 l i s ts a n u m be r o f ene r g y se r v i c es o f l i g h t, t h ose te c h n o l o g y s ys te ms s i g n i f i c a n t l y d i ss i m i l a r t o t h ose o f t he p o w e r an d t he r m a l se r v i c es w e r e e x c l u de d f r o m t h i s s t u d y.

Table : Classification of the active systems that form part of the S ET R M


Power

S i n g u l a r h o useh o l ds

S m a l l

< 5 k W C o n v e n t i o na l w i t h o u t t r a c k i n g p h o t o v o l t a i c

M i n i o f f-g r i d f o r s ma l l c o m m u n i t i es< 200 k W

C o n v e n t i o na l w i t h / w i t h o u t t r a c k i n g, o r c o n ce n t r a t e d p h o t o v o l t a i c

C o m m e r c i a l b u i l d i n gs / A g r i c u l t u r e sec t o r M e d i u m < 1 M WC o n v e n t i o na l, o r t h i n f i l m w i t h / w i t h o u t t r a c k i n g, o r c o n c en t r a t e d p h o t o v o l t a i c

I n d us t r y sec t o r

L a r g e

> 1 M WC o n ce n t r a t e d, o r t h i n f i l m w i t h t r a c k i n g p h o t o v o l t a i c

C o n c e n t r a t e d (ther m a l) p o w e r

M u n i c i pa l i t i es / c o m m e r c i a l c l u s te r s > 1 M WC o n ce n t r a t e d, o r t h i n f i l m w i t h t r a c k i n g p h o t o v o l t a i c / pa r ks

C o n c e n t r a t e d (ther m a l) p o w e r

N a t i o na l g r i d > 1 M WC o n ce n t r a t e d, o r t h i n f i l m w i t h t r a c k i n g p h o t o v o l t a i c / pa r ks

C o n c e n t r a t e d (ther m a l) p o w e r / pa r k s

Thermal S i n g u l a r h o useh o l ds / c o m m u n i t i es f o r w a t e r an d spa ce heat i n g

L o w< 80º C N o n-t r ac k i n g c o l l e c t o r s

S i n g u l a r h o useh o l ds / c o m m u n i t i es f o r c o o k i n g

< 1 00º C N o n-t r ac k i n g c o l l e c t o r s

C o m m e r c i a l b u i l d i n gs / A g r i c u l t u r e sec t o r f o r c o o l i n g (adso r p t i o n c h i l l e r s)

60 - 90º C N o n-t r ac k i n g c o l l e c t o r s

C o m m e r c i a l b u i l d i n gs / A g r i c u l t u r e sec t o r f o r c o o l i n g (adso r p t i o n c h i l l e r s, s i n g l e an d d o u b l e ac t i o n)

75 - 1 1 5 º C

N o n-t r ac k i n g c o l l e c t o r s

M u n i c i pa l i t i es / c o m m e r c i a l c l u s te r s / i n d us t r y sec t o r f o r m u l t i e f f e c t desa l i na t i o n (ME D)

< 70º C N o n-t r ac k i n g c o l l e c t o r s

M u n i c i pa l i t i es / c o m m e r c i a l c l u s te r s / 90 - N o n-t rac k i n g c o l l e c t o r s

1

1

A c t i v e so l a r te c h n o l o g i es a re e m p l o y e d t o c o n v e r t so l a r e ne r g y i n t o usa b l e h ea t o r e l e c t r i c i t y, ca use a i r-m o v e m e n t f o r v e n t i l a t i o n o r c o o l i n g, o r s t o re hea t f o r f u t u r e use. A c t i v e so l a r s ys te ms use e lec t r i ca l o r m e c h a n i c a l eq u i p m e n t, suc h as p u m ps an d f a ns, t o i n c rease t he usa b l e h ea t i n a s ys te m.

2

2

Pass i v e so l a r tec h n o l o g i es c o n v e r t su n l i g h t i n t o usa b l e hea t, ca use a i r-m o v e m e n t f o r v e n t i l a t i o n o r c o o l i n g, o r st o re hea t f o r f u t u r e use, w i t h o u t t he ass is ta n ce o f o t he r ene r g y so u r c es.

i n d us t r y sec t o r f o r desa l i na t i o n b y m e m b r a ne d i s t i l l a t i o n

1 00º C

C o m m e r c i a l b u i l d i n gs / A g r i c u l t u r e sec t o r / i n d us t r y sec t o r f o r c o o l i n g (adso r p t i o n c h i l l e r s, s i n g l e an d d o u b l e ac t i o n)

M e d i u m

1 30 - 1 80º C

C o n ce n t r a t e d t he r m a l w i t h t r a c k i n g, spec i f i c a l l y w i t h a s i m p l e pa ra b o l i c t r o u g h

M u n i c i pa l i t i es / c o m m e r c i a l c l u s te r s / i n d us t r y sec t o r f o r desa l i na t i o n b y m u l t i sta ge f l as h (MSF) d i s t i l l a t i o n

90 - 1 20º C

N o n-t r ac k i n g c o l l e c t o r s, o r c o n c en t r a t e d t he r m a l w i t h t r a c k i n g, spec i f i c a l l y w i t h a s i m p l e pa ra b o l i c t r o u g h

I n d us t r y sec t o r f o r p r o cess hea t < 250º CC o n ce n t r a t e d t he r m a l w i t h t r a c k i n g, spec i f i c a l l y w i t h a s i m p l e pa ra b o l i c t r o u g h an d l i n ea r F r es ne l

I n d us t r y sec t o r f o r p r o cess hea t

H i g h

< 500º CC o n ce n t r a t e d t he r m a l w i t h t r a c k i n g, spec i f i c a l l y w i t h a ad va n ced pa r a b o l i c t r o u g h an d l i nea r F r es ne l

I n d us t r y sec t o r f o r t he r m o c he m i s t r y an d f u e l s

> 750º CC o n ce n t r a t e d t he r m a l w i t h t r a c k i n g, spec i f i c a l l y w i t h a ce n t r a l re ce i v e r

3. MethodologyA te c h n o l o g y r oa d ma p (TR M) is a f l e x i b l e an d p o w e r f u l te c h n i q ue f o r su p p o r t i n g te c h n o l o g y m a na ge me n t an d p l a n n i n g an d ca n be ada p te d t o m a n y st ra te g i c s i t ua t i o n s. T h e f l e x i b i l i t y o f t he m e t h o d m a y be c o ns i d e re d st re n g t h an d a w ea k n ess a rea, i n t ha t a l t h o u g h i t ca n be ap p l i e d i n m a n y c o n te x ts, i t t h e n has t o be c us t o m i z e d i n o r de r t o f i t t h e pa r t i c u l a r ap p l i c a t i o ns. T h e d i v e r se w a y s t o c o ns t r u c t a T R M m a y be d ue t o a l a c k o f c lea r an d ac ce p te d sta n da r ds o r g u i d e l i n es (Phaa l e t a l., 2004); ne v e r t he l ess, e f f e c t i v e r oa d ma ps ha ve bee n de v e l o pe d f o r v a r i o u s sec t o r s, i n c l u d i n g so la r ene r g y sec t o r s (Pr i ce an d K e a r ne y, 1 999; Sa r gea n t an d L u n d y, 2003; A B C S E, 2004; P i t z-Paa l e t a l., 2005; W W G and M M A , 2008).

A T R M o f f e rs a f r a m e w o r k t o i n te g ra te m a r k e t, p r o d u c t, an d te c h n o l o g y e v o l u t i o n; i t i s a p l a n n i n g p r o cess t o he l p i d e n t i f y, se le c t, an d de v e l o p te c h n o l o g y a l te r n a t i v es t o sa t is f y a se t o f p r o d u c t nee ds (Gar c i a an d B r a y, 1 9 97) an d is use d t o c o l l e c t i n f o r m a t i o n f r o m a w i d e v a r i e t y o f so u r ces. W i t h t h i s i n f o r m a t i o n d y na m i c nea r-, m i d-, an d l o n g-te r m p l a ns ca n be de v e l o pe d f o r r esea r c h an d de ve l o p m e n t (R& D) i n v es t m e n ts, as w e l l as ne w p r o d u c t/ser v i c e an d p r o cess de ve l o p me n ts. I n ge ne ra l, r oa d ma ps i de n t i f y te c h n o l o g i es u n de r l y i n g c u r re n t an d p l a n ne d p r o d u c ts an d/or se r v i c es an d h i g h l i g h t t h e k n o w n te c h n o l o g y de ve l o p m e n ts t ha t a re e x pec te d, an d t he e le me n ts t ha t w i l l be nee de d t o su c cess f u l l y de v e l o p t hese i n t o ne w p r o d u c ts an d/or se r v i c es (Pet r i c k an d E c h o l s, 2004). T h i s T R M i n te g ra tes w h a t i s k n o w n a t a l l l e ve ls i n t he so la r ene r g y sec t o r, an d t he asso c ia te na t i o na l s ys te m o f i n n o v a t i o n (NS I), i n t o a f r a m e w o r k t ha t su p p o r t s s t ra te g i c resea r c h i n i t i a t i v es f o r S o u t h A f r i c a.

A T R M i s a nee ds-d r i v e n, an d n o t a so l u t i o ns-d r i v e n, ap p r oa c h (Ind us t r y C a na da, 2008). S u bse q ue n t l y, t he p r o cess o f de ve l o p i n g t h i s S o u t h A f r i c a n so la r ene r g y te c h n o l o g y r oa d ma p (SE T R M) d i d n o t sta r t w i t h an en d-p o i n t assu m p t i o n t ha t t he re w i l l be a ce r ta i n l e ve l o f de p l o y m e n t o f so la r ene r g y s ys te ms at so me p o i n t i n t he f u t u r e. R a t her, t h e nee d an d m a r k e t p o te n t i a l f o r so la r ene r g y resea r c h i n S o u t h A f r i c a ha v e bee n assessed, ta k i n g i n t o acc o u n t c o m pe t i n g o p t i o ns i n t he N S I i n w h i c h t he resea r c h w i l l ta ke p l a ce i n. T o de ve l o p a c re d i b l e an d de f e ns i b l e S E T R M f o r use b y t he S o u t h A f r i c a n g o v e r n me n t an d t he N S I, t o ge t he r w i t h su p p l i e rs an d c us t o m e rs i n t he so la r ene r g y s ys te m v a l u e c ha i ns, t he C R S E S an d t he G S T M ha v e:

• U n d e r ta ke n b o t t o m-u p da ta ga t he r i n g t h r o u g h d i re c t c o ns u l ta t i o n w i t h s ta ke h o l d e rs b y ca r r y i n g o u t o ne-o n-o ne i n t e r v i e w s w i t h resea r c he rs i n t he N S I , an d i n d u s t r y, an d u t i l i s i n g m a te r i a l o b ta i n e d f r o m v a r i o us S o u t h A f r i c a n w o r k s h o ps (for e xa m p l e E d k i n s et a l., 2009 an d C S I R, 2009) an d t he I S E S S o l a r W o r l d C o n g r ess 2009, ab o u t o p p o r t u n i t i es an d c o ns t ra i n ts f a c i n g so la r ene r g y te c h n o l o g i es;

• U n d e r ta ke n des k t o p r esea r c h i n o r de r t o c o l l e c t an d re v i e w re le va n t na t i o na l an d i n te r n a t i o na l p u b l i c a t i o n s an d t he o u t p u ts o f s i m i l a r r oa d ma p p i n g e xe r c i ses e lse w h e r e;

• A n a l y se d t he c o l l e c te d da ta t o assess t he m a r k e t, i n d us t r y-de ve l o p me n t an d te c h n o l o g y resea r c h an d de ve l o p me n t p o te n t i a l i n S o u t h A f r i c a;

• C o m p l e te d a d r a f t r oa d ma p d o c u me n t, an d tes te d i t an d t he ana l y ses be h i n d i t, b y c i r c u l a t i n g t he d o c u m e n t t o sta ke h o l d e rs i n t he N S I, i n d u s t r y an d g o v e r n m e n t, f o r c r i t i q u e an d c o m m e n ts; an d

• F i n a l i se d t he r oa d ma p d o c u me n t a f te r a w o r k s h o p en ga ge me n t w i t h d i f f e re n t s ta ke h o l d e rs, d u r i n g F e b r ua r y 20 10.

I t i s e m p has ise d t ha t t h e o n g o i n g de v e l o p m e n t o f t he S E T R M is d o ne w i t h t he bes t a va i l a b l e da ta a t t h e t i m e as t he o v e ra l l p r o j e c t p r o g r esses, b u t t he N S I w i l l s t i l l ha v e t o ad j us t t o resea r c h suc cesses an d f a i l u r es t o reac h t he v i s i o n an d g oa l s as se t o u t i n t he S E T R M .

2. A CT I V E SOLA R E N E R G Y T EC H NO LOG Y SYST E M S

1. Power applicationsA s i n d i c a te d i n sec t i o n 1 . 1 (and Ta b l es 1 an d 2), p o w e r ap p l i ca t i o ns re f e r t o t h ose te c h n o l o g i ca l s ys te ms t ha t c o n v e r t so la r ra d i a t i o n i n t o e le c t r i c i t y, t o d i f f e re n t i a te t he m f r o m t h ose so la r s ys te ms t ha t, i ns tead, c o n v e r t t h e ra d i a t i o n i n t o use f u l t h e r m a l ene r g y o r t h ose t ha t use t he l i g h t i tse l f f o r ap p l i ca t i o ns su c h as de t o x i f i c a t i o n. T h i s sec t i o n i s su bseq ue n t l y d i v i d e d i n t o t he f o l l o w i n g :

1 . Ph o t o-e le c t r i c s ys te ms t ha t c o n v e r t l i g h t t o e le c t r i c i t y d i r e c t l y ;

2. C o n ce n t ra te d so la r p o w e r (CSP) s ys te ms t ha t c o n ce n t ra te so la r hea t f o r c o n v e rs i o n i n hea t en g i n es t o e le c t r i c i t y ; an d

3. N o n-c o n ce n t ra t i n g so la r t he r m a l p o w e r s ys te ms, na me l y so l a r c h i m n e ys an d so l a r p o n ds.

1.1. Photoelectric systemsPh o t oe le c t r i c o r p h o t o v o l t a i c (PV) de v i c es c o n v e r t su n l i g h t d i r e c t l y i n t o e le c t r i c i t y t h r o u g h t he use o f se m i c o n d u c t o rs. Se m i c o n d u c t o r te c h n o l o g y i s t y p i c a l l y c l ass i f i e d i n t w o g r o u ps, na me l y c r y s ta l l i n e te c h n o l o g y (sin g le c r y s ta l l i n e s i l i c o n, p o l y c r y s ta l l i n e s i l i c o n, r i b b o n s i l i c o n an d I I I-V m a te r i a ls) an d t h i n f i l m te c h n o l o g y (amo r p h o us s i l i c o n, ca d m i u m te l l u r i d e an d c o p pe r-i n d i u m-d i se le n i d e) (van D y k , 2007). C o n ce n t ra t o r

te c h n o l o g y has l a r ge l y b u i l t o n t he se m i c o n d u c t o r te c h n o l o g y, w h i l s t p o l y m e r an d c he m i ca l ce l l s 3a re i n t he i n i t i a l s ta ges o f i n v es t i ga t i o n (van D y k, 2007). T h e p r o d u c t i o n o f P V ce l l s has i n c r eased stead i l y i n t he l as t y ea rs, d r i v e n b y t he p r o g r ess i n de ve l o p me n t o f m a te r i a l s an d p r o cess i n g te c h n o l o g i es; a t o ta l i ns ta l l e d ca pac i t y o f 1 40 000 M W is en v i sa ge d b y 2030 (see sec t i o n 3. 1. 1). I n o r de r t o m a ke P V m o r e c o m pe t i t i v e, a p re v i o us resea r c h-o r i e n te d r oa d ma p (Jäger-W a l d a u, 2004) ha d h i g h l i g h t e d t ha t f u t u re resea r c h e f f o r ts nee d t o f o c u s o n te c h n o l o g y de v e l o p me n ts t ha t w i l l i m p r o v e t he c os t-e f f i c i e n c y r a t i o s o f t he d i f f e r e n t P V te c h n o l o g i es f o r h i g he r c o m p e t i t i v e ness (see F i g u r e 4 an d sec t i o n 3. 1. 1).

Figure : Generations of solar cells – cost versus efficiency (Source: Jäger-Waldau, 2004)

T h r ee P V te c h n o l o g y c o n f i g u r a t i o ns a re su bseq ue n t l y d i s c ussed i n t h i s S E T R M , na me l y c o n v e n t i o na l P V s ys te ms, c o n ce n t ra t i n g P V s ys te ms, an d t h i n f i l m s ys te ms, i n c l u d i n g d y e-sens i t i z e d so la r ce l l s.

1.1.1. Conventional photovoltaicI n c o n v e n t i o na l P V s ys te ms (of te n ca l l e d f l a t p l a t P V te c h n o l o g y) t he se m i c o n d u c t o r ce l l s d i r e c t l y abs o r b t he so la r ra d i a t i o n an d d o n o t u t i l i se an y m i r r o r s o r l e nses t o c o n ce n t ra te t he so la r ra d i a t i o n o n t o t he se m i c o n d u c t o r

3

3

P o l y m e r so l a r ce l l s a re f l e x i b l e a n d c o m e i n m a n y f o r m s i n c l u d i n g o r ga n i c so l a r ce l l s (also ca l l e d p l as t i c so l a r ce l l s), o r o r ga n i c c he m i s t r y p h o t o v o l t a i c ce l l s, t ha t p r o d u ce e le c t r i c i t y f r o m sun l i g h t us i n g p o l y m e rs.

ce l l s. T h e ce l l s a re t y p i ca l l y a r ra n ge d i n a f l a t p l a te c o n f i g u r a t i o n an d b u i l t i n t o an ap p r o p r i a te s t r u c t u r e (see F i g u r e 5). T h e s i ze o f t he pa ne l de pe n ds o n t he pa r t i c u l a r ap p l i ca t i o n an d o u t p u t re q u i r e d. D e p e n d i n g o n t he ap p l i c a t i o n, t he st r u c t u re ca n be f i x e d o r t ra c ke d (sin g l e o r m u l t i a x i s) t o f o l l o w t he su n f o r m a x i m u m so la r ra d i a t i o n abs o r p t i o n. T h e st r u c t u re i s t he n i n te g ra te d i n t o a b r oa de r P V so l a r s ys te m, des i g ne d f o r a spec i f i c ap p l i c a t i o n w i t h i n t he f r a m e w o r k o f Ta b l e 1 . A t y p i c a l c o n v e n t i o na l P V s ys te m c o u l d t h us be st r u c t u r e d i n t o t he f o l l o w i n g su bs ys te ms:

• T h e se m i c o n d u c t o r pa ne l;

• T h e pa ne l s t r u c t u re, w h i c h c o u l d a ls o be a b u i l d i n g i n te g r a te d st r u c t u r e, e.g. P V r o o f t i l es;

• T h e m a x i m u m p o w e r p o i n t t ra c k i n g s ys te m (not f o r a f i x e d s ys te m);

• T h e i n v e r te r an d ad d i t i o na l e le c t r i ca l c o n t r o l s ys te m; an d, i f nee de d

• S t o ra ge, e.g. dee p-c y c l e ba t te r i es.

Figure : Conventional P V flat plate configuration (Source: Abengoa Solar, 2008)

1.1.2. Concentrating photovoltaicC o n ce n t ra t i n g o r c o n ce n t ra te d P V s ys te ms u t i l i se m i r r o r s o r l e nses t o c o n ce n t ra te t he so la r r a d ia t i o n o n t he se m i c o n d u c t o r ce l l s. A s i n d i c a te d i n Ta b l e 2 c o n ce n t ra te d P V s ys te ms a re u t i l i se d f o r m e d i u m t o l a r g e p o w e r o u t p u t. B e c a use o f t h e h i g he r o u t p u t de ma n ds, c o n ce n t ra te d P V s ys te ms a re s i n g l e-o r m u l t i-a x i s t ra c k e d (see F i g u r e 6). F o r l o w c o n ce n t ra t i o n P V, m i r r o r s a re us ua l l y use d. F o r m e d i u m c o n ce n t ra t i o n P V ap p l i c a t i o n s, a va i l a b l e c o m m e r c i a l s ys te ms w o u l d t y p i c a l l y use F res ne l l i n e f o c us l e nses an d f o r h i g h c o n ce n t ra t i o n ap p l i c a t i o ns, F r esne l p o i n t f o c us l e nses (Abe n g oa S o l a r, 2008).

Figure: Single- and multi-axis tracking systems (Source: Abengoa Solar, 2008)

A s ys te m b rea k d o w n o f a t y p i c a l c o n ce n t ra te d P V s ys te m w o u l d t h us i n c l u de t he su bs ys te ms i de n t i f i e d f o r a c o n v e n t i o na l s ys te m (sem i c o n d u c t o r pa ne l, pa ne l s t r u c t u re, m a x i m u m p o w e r p o i n t t ra c k i n g s ys te m, i n v e r te r an d

e le c t r i c a l c o n t r o l s ys te m an d, i f nee de d, st o ra ge), b u t i n ad d i t i o n a ls o an o p t i ca l s ys te m (mi r r o rs o r l e nses) t o c o n ce n t ra te t he so la r r a d ia t i o n (see F i g u r e 7).

Figure : F lat-plate concentrated P V modules (Source: green-planet-solar-energy.com)

1.1.3. Thin film photovoltaicT h i n f i l m P V ce l ls a re m a de b y de p os i t i n g o ne o r m o r e t h i n l a y e rs o f p h o t o v o l t a i c m a te r i a l o n a su bs t ra te (see F i g u r e 8). T h e t h i c k ness ra n ge o f a l a y e r v a r i es f r o m a f e w na n o me te rs t o se ve ra l m i c r o me te rs. T h i n f i l m so l a r ce l l s a re us ua l l y ca te g o r i sed acc o r d i n g t o t he p h o t o v o l t a i c m a te r i a l u sed, suc h as a m o r p h o us s i l i c o n (a-S i), ca d m i u m te l l u r i d e (CdTe), c o p pe r i n d i u m ga l l i u m se le n i d e (CIS o r C I G S), an d d y e-sens i t i se d so la r ce l l s (DSC), a m o n gs t o t h e rs (van D y k, 2007). T h i n f i l m te c h n o l o g y i s n o t y e t as e f f i c i e n t as t ra d i t i o na l se m i c o n d u c t o r te c h n o l o g y (Jäge r-W a l da u, 2004), as is sh o w n i n F i g u r e 9, b u t i ts l i g h t w e i g h t an d p o t e n t i a l l o w c os t m a ke i t i d ea l f o r ce r ta i n ap p l i c a t i o n s. D u e t o i t s h i g h e f f i c i e n c y an d l o w e r m a te r i a l c os t, C I G S so la r ce l l s a re e me r g i n g as o ne o f t he m o s t p r o m i s i n g t h i n f i l m te c h n o l o g i es. T h e d o w n s i de o f t h i s te c h n o l o g y, h o w e v e r, i s t he v e r y c o m p l i c a te d an d ca p i ta l-i n te ns i v e m a n u f a c t u r i n g p r o cess (see sec t i o n 2. 1. 1.4). I m p o r t a n t pe r f o r m a n ce pa ra me te rs f o r t h i n f i l m so la r ce l l s i n c l u de (A l be r ts, 2009): e f f i c i e n c y p o t e n t i a l; sta b i l i t y d u r i n g o pe ra t i o n; v i s ua l ap pea ra n ce; ec o n o m i c l i f e; an d l o w p r o d u c t i o n c os t.

Figure : F lexible a-S i on a polymer substrate (Source: van Dyk, 2007)

Figure : Best research-cell efficiencies (Source: N R E L, 2004)

1.1.4. P hotovoltaic m anufacturing researchJäge r-W a l da u (2004) ha d sh o w n t ha t f o r a l l P V te c h n o l o g i es an d i n a l l de v e l o p me n ts h i g h e f f i c i e n c y, l o w c os t an d, espec ia l l y, p r o d u c i b i l i t y a re i n t e g ra l, h i g h-p r i o r i t y aspec ts. T h ese f i n d i n g s a re su m m a r i se d i n Ta b l es 3 t o 8. T h e l as t t w o c o l u m ns o f t he Ta b l es re f l e c t t he t he n-e x pe c te d rea d i n ess o f t h e r esea r c he d m a n u f a c t u r i n g i ssues f o r p r o d u c t i o n r o l l-o u t, an d t he p r i o r i t y o f t h ese resea r c h ac t i v i t i es t o i m p r o v e t he e f f i c i e n c y, c os t an d p r o d u c i b i l i t y o f P V te c h n o l o g i es.

Table : I nternational research priorities for crystalline / m ulticrystalline silicon P V

I ssue Ready P riority

H i g h-t h r o u g h p u t shee ts y i e l d, r ea r pass i v a t i o n, B S R 2006 1

T h i n w a f e r s (sl i c i n g, p r o cess i n g) 2005 2

L o w-c os t su r f a ce pass i v a t i o n 2007 3

L o w-c os t b u l k pass i v a t i o n 2006 3

H i g h-t h r o u g h p u t p r o cess i n g 2007 3

A l t e r na t i v e en ca ps u l a n t s 2008 4

A t t r a c t i v e g r i d des i g ns 2004 4

I n-l i ne c ha r ac te r i sa t i o n 2004 5

R e c y c l i n g o f m o d u l es an d B O S 20 10 5

Table : I nternational research priorities for I I I -V m aterials4


L o w-c os t subs t r a t e 20 1 0 1

N e w st r u c t u r esη> 40 % 2020 1

H i g h-t h r o u g h p u t de p os i t i o n 20 1 5 2

L o w-c os t c o n c en t r a t o r s 2007 3

T P V 20 10 3

Table : I nternational research priorities for amorphous and thin-film silicon


H i g h-t h r o u g h p u t de p os i t i o n (µ -S i) p r o cess an d eq u i p m e n t 2006 1

T C O l o w-c os t, te x t u r e 2006 1

U n d e r s ta n d i n g o f i n t e r f a ces 20 1 5 1

U n d e r s ta n d i n g o f st r u c t u r e (sho r t an d l o n g r a n ge) 20 1 5 1

F l e x i b l e (plast i c) su bs t r a t es 2008 2

I n-l i ne c ha r ac te r i sa t i o n (un i f o r m i t y) 2006 2

I n s i t u sh u n t de te c t i o n (and re pa i r) 2005 3

Pac k a g i n g (hum i d i t y) 2005 3

E q u i p m e n t sta n da r d i sa t i o n 20 1 5 3

G e ne r a l sta b i l i t y o f de v i c e 20 1 0 4

Pat t e r n i n g tec h n o l o g y 2005 5

Table : I nternational research priorities for film c-S i


L o w-c os t S i-r i b b o n 2007 1

H i g h-t h r o u g h p u t de p os i t i o n r eac t o r 2008 1

C e r a m i c subs t r a t e de v e l o p m e n t 20 1 0 1

E p i t a x i a l ce l l p r o cess (wi t h b u r i e d S i-based r e f l e c t o r) 2008 2

L o w-c os t g r a i n s i ze en ha n ce m e n t m e t h o ds 20 1 0 3

L o w-c os t p r o cess f o r m o n o l i t h i c m o d u l es o n ce r a m i c 20 1 2 3

Table : I nternational research priorities for CdTe and C I S


S u bs t r a t e g l ass spec i f i c a t i o ns 2004 1

H e a l t h an d sa fe t y issues 2005 1

Pac k a g i n g/la m i n a t i o n (Hu m i d i t y) 2005 1

B a c k c o n ta c t 2005 1

Pat t e r n i n g tec h n o l o g y 2005 1

T C O l o w-c os t, te x t u r e 2006 1

F l e x i b l e (plast i c) su bs t r a t es 2008 2

S t o i c h i o m e t r y an d u n i f o r m i t y 20 1 0 2

E q u i p m e n t sta n da r d i sa t i o n 20 1 5 2

U n d e rs ta n d i n g o f i n t e r f a ces 20 1 5 2

R e c y c l i n g o f m o d u l es an d B O S 20 1 5 2

Fa i l u r e de te c t i o n an d r e pa i r 20 1 5 3

4

4

V a r i e t y o f m a t e r i a l s w i t h v e r y h i g h c o n v e rs i o n e f f i c i e n c i es ca te g o r i z e d as G r o u p I I I a n d G r o u p V e le m e n t s i n t he Pe r i o d i c Ta b l e.

N e w de v i ce c o n c ep ts 2020 4

Table : I nternational research priorities for novel ideas to exploit the ultimate efficiency potential of the P V effect


C o l l e c t i o n o f ge ne ra te d ca r r i e r s (li f e t i m e, c har ge sepa ra t i o n m o b i l i t y, d i s t a n ce) 2007 1

M i c r os t r u c t u r e (pro cess i n g, stab i l i t y) 20 10 1

L o w-c os t m a t e r i a l s an d p r o cess i n g n o n-v a c u u m (e.g. p r i n t i n g) 20 1 5 1

S u i t a b l e m a t e r i a l s ba n d ga p en g i n ee r i n g 20 1 5 2

U n d e rs ta n d i n g o f i n t e r f a ces 2020 2

S t a b i l i t y (ox i da t i o n) 20 1 5 3

I n ge ne ra l c o m m o n i ssues a m o n gs t a l l d i f f e re n t ce l l te c h n o l o g i es r e la te d t o m a n u f a c t u r i n g, sca l i n g-u p, re l i a b i l i t y o f m o d u l es an d s ys te ms as w e l l as sta n da r d i sa t i o n o f p r o d u c ts an d tes t i n g p r o ce d u res. F o r t h i n f i l m te c h n o l o g i es t he f o l l o w i n g a re spec i f i c a l l y n o t e d (Jäger-W a l d a u, 2004):

• Substrate: G l ass an d T C O q ua l i t y a re i m p o r t a n t f o r a l l t h i n-f i l m te c h n o l o g i es. T h i s t o p i c i n c l u des i ssues suc h as, l o w i r o n c o n te n t o r p r o pe r ha ze t o m i n i m i se o p t i ca l l oses. A t t he sa me t i m e a l te r na t i v e f l e x i b l e su bs t ra tes suc h as m e ta l o r p l as t i c f o i l s sh o u l d be i n v es t i g a te d i n m o r e de ta i l.

• Equipment: N o sta n da r d eq u i p m e n t i s a va i l a b le. B e ca use o f t he c us t o m m a de eq u i p m e n t t h e ca p i ta l c os t f o r s ta r t-u ps i n t h i n-f i l m m a n u f a c t u r i n g a re r a t h e r h i g h. E s pec i a l l y l a r ge a rea eq u i p m e n t f o r a l l t h i n f i l m P V is nee de d t o, f o r e xa m p l e, i n c r ease t he de p os i t i o n r a te f o r h i g he r t h r o u g h p u t b u t a t t h e sa me t i m e w i t h g o o d m a te r i a l q ua l i t y an d g o o d h o m o ge ne i t y f o r a h i g h y i e l d. T h e r e f o r e, resea r c h an d de v e l o p m e n t o f m a n u f a c t u r i n g p r o cesses an d eq u i p m e n t a re nee de d t o ad d ress ce r ta i n c o m m e r c i a l l i m i t a t i o ns (see F i g u r e 1 0).

• Patterning: H i g h t h r o u g h p u t te c h n o l o g i es a re nee de d an d a l te r na t i v e (e.g. c he m i ca l) m e t h o ds sh o u l d be i n v es t i ga te d. I ss ue c o n ce r n i n g l ase r sc r i b i n g, espec ia l l y o f ta n de m ce l l s w i t h T C O i n te r m e d i a te l a y e rs, an d t he i n te g ra t i o n nee d f u r t h e r resea r c h.

• Stability: S t i l l t o be so r te d o u t f o r a l l t h i n f i l m te c h n o l o g i es. E n ca ps u la t i o n o f t h i n-f i l m so la r ce l l s: A t c u r re n t t h e used te c h n o l o g i es a re n o t r o b us t en o u g h t o i n c rease c o n f i d e n ce. A l t e r n a t i v e an d n o v e l m a te r i a l s nee d m o r e a t te n t i o n.

• Certification: I n o r de r t o g ua ra n tee re l i a b l e an d c o m pa ra b l e l a be l l i n g o f t he d i f f e re n t m o d u l e-t y pes f o r t he c us t o m e r, w e l l de f i n e d tes t i n g sta n da r ds an d m e t h o ds ha v e t o be esta b l i s h e d f o r eac h te c h n o l o g y.

• Quality of materials: F o r a l l P V-s ys te m c o m p o ne n ts a h i g he r q ua l i t y i s des i r a b le t o ensu re h i g he r s ys te m e f f i c i e n c i es. T h e t o p i cs t he re ra n ge f r o m t he base m a te r i a l, e.g. r o l e o f i m p u r i t i es, be t te r u n de rs ta n d i n g o f m e ta l l u r g i ca l i n te r f a ces t o t he re l i a b i l i t y o f e le c t r i ca l c o m p o n e n ts use d i n i n v e r te rs.

• Quality control: M e t h o ds i n s i t u p r o cess m o n i t o r i n g nee de d t o be i m p r o v e d.

Figure : F irst generation diffusion process for thin film processing and com mercial limitations

(Source: Alberts, 2009)

1.2. Concentrated solar power systemsC o n ce n t ra te d S o l a r P o w e r (CSP) s ys te ms use c u r v e d m i r r o r asse m b l i es t o c o n ce n t ra te t he i n c i d e n t so l a r f l u x o n t o an abso r be r, t h e re b y r a is i n g t he te m pe ra t u r e o f a hea t t ra ns f e r f l u i d. T h i s hea t i s t he n c o n v e r te d i n a hea t en g i n e (stea m o r gas t u r b i n e, o r S t i r l i n g en g i n e) i n t o r o ta t i o na l p o w e r d r i v i n g an e le c t r i ca l ge ne ra t o r. A bas i c s ys te m is de p i c te d i n F i g u r e 1 1 , w h e re t he p o r t i o n i n d i c a te d o n t he r i g h t s i de c o m p r i ses te c h n o l o g y f r o m t he c o n v e n t i o na l e le c t r i c i t y ge ne ra t i o n sec t o r.

Figure : A basic parabolic trough steam cycle (Source: Solar M i llennium; solarmillennium.de)

T h e s ys te m ca n be des i g ne d t o c o l l e c t m o r e hea t t ha n re q u i r e d a t t he des i g n p o i n t, an d t h i s e x cess hea t ca n t he n be st o re d i n a t he r m a l st o ra ge s ys te m. H ea t ca n be st o re d m o r e c hea p l y t ha n e le c t r i c i t y, an d t he st o re d hea t ca n t he n be w i t h d r a w n f r o m st o ra ge an d used i n pe r i o d s o f i n s u f f i c i e n t su ns h i n e. T h e hea t t ha t i s re q u i r e d ca n a ls o be m a de u p b y b u r n i n g f u e l (foss i l f u e l h y b r i d i sa t i o n). T h ese so l u t i o ns p r o v i d e a b u f f e r aga i ns t c l o u d y pe r i o d s, e x te n d ge ne ra t i o n t o c o v e r pea k l o a d, an d ena b l e a C SP p l a n t t o ge ne ra te p o w e r a f te r su nse t; an d so a l l o w a l e v e l o f d i s pa t c ha b i l i t y, w h i c h se ts C SP te c h n o l o g y apa r t f r o m o t he r i n t e r m i t t e n t re ne w a b l e ene r g y te c h n o l o g i es su c h as w i n d. T h e i n c l us i o n o f s t o ra ge an d/or h y b r i d i sa t i o n b y t he use o f f o ss i l f u e l s i s w e l l i l l u s t r a te d b y S ta le y et a l. (2009) i n F i g u r e 1 2 (quo te d b y E d k i n s et a l., 2009), w h e r e, b y e xa m p l e, t he sa me c o l l e c t o r f i e l d o f 1 ,089 920 m 2ca n be c o n f i g u r e d i n f o u r d i f f e re n t w a y s:

• W i t h o u t s t o ra ge o r h y b r i d i sa t i o n: T h e f i e l d w i l l d r i v e a 200 M W e l t u r b i n e a t f u l l l o a d f o r 2000 h o u rs a y ea r, na me l y w i t h a ca pac i t y f a c t o r o f 23 %, de l i v e r i n g 400 G W h e a y ea r, b u t w i l l o n l y de l i v e r d u r i n g su ns h i n e h o u rs.

• W i t h 6 h o u rs o f t he r m a l s t o ra ge: I n o r de r t o l o a d so me o f t he c o l l e c te d ene r g y i n st o ra ge l ess i s a va i l a b l e f o r i m m e d i a te use b y t he t u r b i n e, so t he t u r b i n e s i ze dec r eases. I n t h i s case t he f i e l d w i l l d r i v e a 1 00 M W e

t u r b i n e an d c ha r ge 6 h o u rs o f s t o ra ge, res u l t i n g i n t he t u r b i n e de l i v e r i n g at f u l l l o a d f o r 3500 h o u rs a y ea r, na me l y w i t h a ca pac i t y f a c t o r o f 40 %, de l i v e r i n g 350 G W h e a y ear. T h i s i s l ess t ha t o p t i o n 1 , b u t ca n de l i v e r p o w e r f o r m o r e h o u rs a day, an d u p t o 6 h o u rs o u ts i d e o f su ns h i n e h o u rs.

• W i t h 1 5 h o u rs o f t he r m a l s t o ra ge: T h i s ca n be re ga r de d as a m a x i m u m sto ra ge o p t i o n, w h i c h w i l l de l i v e r p o w e r 24 h o u rs a da y d u r i n g su m m e r, an d l ess d u r i n g w i n t e r. T h e so la r f i e l d, w i t h s t o ra ge, w i l l d r i v e a m u c h s ma l l e r 1 7 M W e t u r b i n e a t f u l l l o a d f o r 62 1 9 h o u rs a y ear, na me l y w i t h a ca pa c i t y f a c t o r o f 7 1 % , de l i v e r i n g 1 06 G W h e y ear.

• H y b r i d i sa t i o n us i n g f o ss i l f u e l, n o st o ra ge: T h i s i s s i m i l a r t o o p t i o n 2, b u t t h e sh o r t f a l l i n so l a r ene r g y i s m a de u p f r o m f o ss i l f u e l, i n t h i s case 35 %. H e r e a 1 00 M W e t u r b i n e de l i v e rs p o w e r a t f u l l l o a d f o r 5668 h o u rs a y ear, na me l y w i t h a ca pa c i t y f a c t o r o f 65 %, de l i v e r i n g 567 G W h e a y ear. T h i s i s t he m o s t o f t he f o u r o p t i o n s w i t h t he g r ea tes t v e rsa t i l i t y.

T h e so la r m u l t i p l e i s t he e x i s t i n g f i e l d s i ze d i v i d e d b y t he t he o re t i ca l f i e l d s i ze nee de d t o d r i v e t he c h osen t u r b i n e a t des i g n p o i n t (typ i ca l l y a t so la r n o o n o n t he sp r i n g o r au t u m n eq u i n o x). I n t he ab o v e f o u r cases, t he so la r m u l t i p l es a re 1 .25, 2.5, 1 4.7 an d 1 .25 respec t i v e l y. O p t i o n s 2 t o 4 t he re f o r e ad d ress t he (poten t i a l) d i sa d va n ta ges o f C SP p l a n ts i n te r ms o f i n t e r m i t t e n ce, w h i c h ca n be m i n i m i se d t h r o u g h t he i n c l us i o n o f st o ra ge o r h y b r i d i sa t i o n, na me l y t he i n t e g ra t i o n o f f o ss i l f u e l s as a bac k u p ge ne ra t i o n so u r ce. T h ese o p t i o n s w o u l d p r o v i d e a b u f f e r aga i ns t c l o u d y pe r i o d s, e x te n d ge ne ra t i o n t o c o v e r pea k l o a d, an d ena b le a C SP p l a n t t o ge ne ra te p o w e r a f te r su nse t. S t o ra ge a ls o i n c reases t he p l a n t ’s ca pac i t y f a c t o r an d, i f o p t i m i z e d f o r t he s i ze o f t he p l a n t an d reso u r ce base, m a y i n so me cases re d u ce t he l e v e l i se d c os t o f e le c t r i c i t y (Ed k i n s e t a l., 2009).

I n te r ms o f t he solar resource collection and conversion pa r t o f F i g u r e 1 1 , E d k i n s et a l. (2009) an d M e y e r (2009) i de n t i f y f o u r m a j o r te c h n o l o g i c a l des i g ns a t p resen t, na me l y pa ra b o l i c t r o u g h, ce n t ra l re ce i v e r o r p o w e r t o w e r, L i n ea r F r es ne l re f l e c t o r s (LF Rs), an d D i s h S t i r l i n g. T h e E C O S T A R stu d y (Pi t z-Paa l e t a l., 2005) c o m p a r e d t he a va i l a b i l i t y, c os ts an d te c h n o l o g y r ead i n ess o f e i g h t c o n f i g u r a t i o n s o f t hese te c h n o l o g i es de m o ns t ra te d i n t he f i e l d. F i g u r e 1 3 c o m p a r es t he c os ts g r a p h i c a l l y. E a c h o f t he te c h n o l o g i es a re at d i f f e re n t te c h n o l o g y rea d i n ess l e ve l s an d h o u rs o f da i l y s t o ra ge, b u t a f e w i n d i c a t o rs e me r ge: D i s h S t i r l i n g i s b y f a r t he m o s t e x pe ns i v e, ce n t ra l re ce i v e r s ys te ms (CRS) and pa ra b o l i c t r o u g hs (PT) w i t h R a n k i n e c y c l e (stea m t u r b i n e) p o w e r c o n v e rs i o n c y c l es ha v e essen t i a l l y t he sa me ca p i ta l an d l e ve l i se d e le c t r i c i t y c os ts, an d so la r gas t u r b i n es (in c o m b i ne d c y c l e) an d L i n ea r F r es ne l (LF) w i t h R a n k i n e ha ve t he l o w es t ca p i ta l c os ts, w i t h t he so la r gas t u r b i n e ha v i n g t he l o w es t l e ve l i se d e le c t r i c i t y c os ts.

Figure : D ifferent C S P plant configurations (Source: Staley et al., 2009)

PT HTF

PT DSG

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CRS sat steam

CRS atm air

CRS gas turbine (hybrid)

Dish Stirling(hybrid)

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Dish Stirling (solar)

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0 0.05 0.1 0.15 0.2 0.25 0.3 0.35 0.4

Electricity cost (EURO/kWh)

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ital c

ost (

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Figure: Comparison of capital end energy costs for eight different C S P systems (Source: P itz-Paal et al., 2005)

I n a l e c t u r e se r i es (RE N A C, 2009) p rese n te d i n Jo ha n nesb u r g i n M a r c h 2009 b y t he R e ne w a b l es A c a de m y o f B e r l i n u n de r t he T R E E (Trans fe r R e ne w a b l e E ne r g y an d E f f i c i e n c y) p r o j e c t, t he c o m p a ra t i v e l a n d re q u i r e m e n t f o r ce n t ra l re ce i v e r, pa ra b o l i c t r o u g h an d F res ne l te c h n o l o g i es i s i l l u s t r a te d b y c o m p a r i n g t he l a n d f o o t p r i n t f o r a 1 00 M W p l a n t m a k i n g use o f t he t h ree te c h n o l o g i es i n an i m a ge sh o w n i n F i g u r e 1 4.

Figure : Comparison for three C S P technologies of land requirement for a 100 M W plant (Source: R E NAC, 2009)

1.2.1. P arabolic troughsPa ra b o l i c t r o u g hs (essen t i a l l y t w o-d i m e ns i o na l pa ra b o l as “e x t r u de d” i n t he t h i r d d i m e ns i o n) c o n ce n t ra te t he so la r ra d i a t i o n i n t w o d i m e ns i o ns o n t o a f o ca l l i n e, ac h i e v i n g c o n ce n t ra t i o ns o f be t w ee n 70 an d 90 su ns (RE N A C , 2009). T h e t r o u g hs c o m p r i se spec ia l l y c u r v e d pa ra b o l i c m i r r o r pa ne ls, he l d i n p l a ce b y e i t he r t r usses at ta c he d t o a t o r q ue t u be, o r a space f r a m e b u i l t as a t o r q ue b o x (see F i g u r e 1 5, m a i n p i c t u re). I n e i t h e r case t he asse m b l i es a re f r ee t o r o ta te ab o u t an a x i s pa ra l l e l t o t he f o ca l l i n e, k ee p i n g t he ra d i a t i o n f o c u ssed o n t he f o ca l l i n e as t he su n m o v es t h r o u g h t he s k y (see F i g u r e 1 5, b o t t o m l e f t). Pa ra b o l i c t r o u g hs ca n be a r ra n ge d n o r t h-so u t h t o t ra c k t he su n east-w e s t i n az i m u t h, o r a r ra n ge d east-w e s t an d t ra c k t he su n i n e le va t i o n. F i g u r e 1 6 sh o w s a c o m pa r i s o n o f n o r t h-so u t h an d eas t-w e s t o r i e n ta t i o ns f o r t he w i n t e r an d su m me r so l s t i ces i n A l b u q u e r q ue, U S A . T h e n o r t h-so u t h o r i e n ta t i o n i s m o r e c o m m o n, as ta ke n o v e r t he y ea r t h i s o r i e n ta t i o n r e ce i v es s l i g h t l y m o r e ene r g y t ha n t he east-w e s t o r i e n ta t i o n.

Figure : P arabolic solar resource collector and conversion unit (Source: Abengoa, 2008; green-planet-solar-energy.com)

Figure : Comparison of clear-day aperture irradiance for different fixed and tracking aperture configurations on the sum mer (left) and winter (right) solstices

(Source: Stine and Geyer, 2001)

L y i n g i n t he f o ca l l i n e i s a se r i es o f abso r be rs t h r o u g h w h i c h a hea t t ra ns fe r f l u i d passes an d is hea ted b y t he c o n ce n t ra te d so la r ra d i a t i o n. T h e abs o r be r c o m p r i ses a m e ta l t u be l y i n g i ns i d e a c o n ce n t r i c g l ass t u be, w i t h t he an n u l a r space be t w ee n t he g l ass en v e l o pe an d t he m e ta l t u be e vac ua te d t o su p p ress c o n v e c t i v e hea t l o ss (see F i g u r e 1 5, t o p r i g h t).

T h e hea t t ra ns fe r f l u i d i s e i t h e r a h i g h te m pe ra t u r e t he r m a l o i l o r w a te r/stea m. T h e m a x i m u m te m pe ra t u r e o f t he r m a l o i l i s 400 C. W i t h su pe r hea te d stea m, h i g he r te m pe ra t u res a re p oss i b l e. E N E A i s e x pe r i m e n t i n g w i t h˚ m o l t e n sa l t as a hea t t ra ns f e r f l u i d. D e s p i te t he r i s k o f t h e sa l t f r ee z i n g be t w ee n 1 20 C an d 200 C, t he r es u l ts˚ ˚ ap pea r t o be p os i t i v e.

T h e hea t f r o m t he hea t t ra ns fe r f l u i d i s used t o ra i se stea m i n a se r i es o f hea t e x c ha n ge rs, w h i c h i s t he n use d t o ge ne ra te e le c t r i c i t y i n a stea m t u r b i n e d r i v e n ge ne ra t o r. T h e pa ra b o l i c t r o u g h w i t h h i g h te m pe r a t u re o i l i s re ga r de d as t he m o s t m a t u re C SP s ys te m, as e xa m p l es ha ve bee n i n c o m m e r c i a l se r v i c e s i n ce t he 1 980’s.

1.2.2. Central receiversI n a ce n t ra l re ce i v e r s ys te m, a f i e l d o f f r ees ta n d i n g he l i o s ta ts, o r an a r ra y o f m o v a b l e o r t ra c k i n g m i r r o r s, i s o r i e n te d t o re f l e c t t he so la r ra d i a t i o n c o n ce n t ra t i n g i t o n a re ce i v e r l o ca te d o n t he u p pe r pa r t o f a ce n t ra l t o w e r (see F i g u re 1 7). T h e re ce i v e r t ra ns f e rs r a d ia n t so la r hea t t o t he o pe ra t i n g f l u i d o f a hea t en g i n e (see F i g u r e 1 8). B e ca use he l i o s ta t f i e l ds c o n ce n t ra te t he so l a r f l u x i n t h ree d i m e ns i o ns t o a p o i n t f o c u s, t he y ca n ac h i e ve so la r c o n ce n t ra t i o ns o f 500 t o 1 000, m u c h h i g he r t ha n t h ose ac h i e v a b l e b y l i n e f o c u s s ys te ms (tro u g hs an d F res ne l s ys te ms). B e ca use o f t he h i g he r c o n ce n t ra t i o n s, h i g he r te m pe ra t u r es a re ac h ie va b l e.

Figure : The central receiver system concept and typical heliostat field configuration (bottom), with a pressurised volumetric receiver for solar gas turbine (top)

(Source: Abengoa, 2008; D R L; sollab.eu/dlr.html)

Figure : A basic central receiving steam system (Source: Abengoa, 2008)

T h e hea t t ra ns fe r f l u i d, w h i c h m a y (or m a y n o t) be t he w o r k i n g f l u i d o f t he hea t en g i n e i t se l f, sa t u ra te d (as i n t he case o f PS 1 0 an d PS20 i n Se v i l l e, S pa i n) o r su pe r hea te d stea m (in t he case o f t he B r i g h t S o u r ce an d E S o l a r t o w e rs), ca n be hea ted d i r e c t l y t h r o u g h t u be b o i l e rs b y t he c o n ce n t ra te d so l a r r a d ia t i o n. F o r e xa m p l e, i n t he 1 .5 M W p l a n t a t Jü l i c h, G e r m a n y (by K r a f t a n la ge n M ü n c he n), a i r hea te d t o 700 C i n ce ra m i c v o l u m e t r i c re ce i v e rs˚ is used t o ge ne ra te stea m a t 485 C an d 27 ba r (Ko l l e t a l., 2009). I n t he case o f so la r gas t u r b i n es, c o m p ressed˚ a i r f r o m t he gas t u r b i n e c o m p resso r i s hea te d t o 800 C i n a p r essu r i sed v o l u m e t r i c r e ce i v e r s a r ra n ge d i n se r i es˚ (SO L G A T E, 2005). Te m pe ra t u r es o f 1 000 C a re en v i sa ge d i n f u t u re w o r k. I n t he S O L H Y C O p r o j e c t, a t u be˚ re ce i v e r i s be i n g used t o ra i se a i r te m pe r a t u re t o 800 C, a f te r w h i c h t he c o m b us t i o n o f f u e l ra ises i t f u r t h e r t o t he˚ 950 C o pe ra t i n g c o n d i t i o n.˚

H e l i o s ta t c os ts pe r sq ua re m e t re o f m i r r o r a re l o w e r t ha n f o r pa ra b o l i c t r o u g hs (€150/m 2as o p p osed t o €206/m 2; P i t z-Paa l e t a l., 2005). H o w e v e r, as pe r F i g u r e 1 4, he l i o s ta t f i e l ds re q u i r e m o r e l a n d t ha n pa ra b o l i c t r o u g hs f o r t he sa me d u t y.

1.2.3. L inear FresnelL i n ea r F r esne l re f l e c t o r s (LF Rs) use l o n g r o w s o f nea r l y f l a t, r o ta t i n g m i r r o r s t o re f l e c t l i g h t a t s ta t i o na r y abso r be rs e le va te d ab o v e t he p l a ne o f t h e m i r r o r s (Ed k i ns e t a l., 2009) (see F i g u r e 1 9). D i f f e re n t abso r be rs use e i t h e r a t he r m a l t ra ns fe r f l u i d o r d i r e c t l y ge ne ra te stea m t o p o w e r t u r b i n es (see F i g u r e 1 9). W h i l e n o t as e f f i c i e n t as pa ra b o l i c d i s hes an d t r o u g hs o r ce n t ra l re ce i v e r s, L F R s o f f e r m a n y p o te n t i a l c os t an d st r u c t u r a l ad v a n ta ges (Ed k i ns e t a l., 2009). I n s tea d o f be i n g a s i n g l e, c o n t i n u o us pa ra b o l a w h i c h c rea tes s i g n i f i c a n t w i n d l o a d i n g, t he l i n ea r F r es ne l c o n ce p t re d u ces t he pa ra b o l a t o a se r i es o f f a ce ts, w i t h t he r o ta t i o n a x i s o f eac h at t h e sa me he i g h t. T h e f a ce ts eac h ha v e m u c h l o w e r w i n d res is ta n ce t ha n t he eq u i v a l e n t pa ra b o l a, w h i c h t he re f o re r e q u i r e m u c h l ess i n t he w a y o f s t r u c t u ra l su p p o r t, t h e re b y r e d u c i n g c os t. T h e f o ca l l e n g t h i s a ls o m a de m u c h l o n ge r (seve ra l m e t r es i n s tead o f ab o u t 2 m e t r es f o r t r o u g hs), a l l o w i n g a l a r g e r r a d i us o f c u r v a t u re (im p l y i n g a f l a t t e r m i r r o r) an d a w i d e r o p t i c a l ape r t u r e. T h e l a r ge, f l a t m i r r o r shee ts a re a ls o m o r e eas i l y m a ss-p r o d u ce d.

Figure : L inear F resnel solar resource collector and conversion unit (Source: Liddell, Novatec, and others, in Meyer, 2009)

T h e de v e l o p m e n t o f t he C o m p a c t L i n ea r F r es ne l R e f l e c t o r (C L F R) c o n ce p t ad d r esses t he se l f-shad i n g an d b l o c k i n g p r o b l e m (M i l l s an d M o r r i s o n, 1 9 97), an d p o te n t i a l l y i n c reases t he l a n d-use ad va n ta ge o f L F R s c o m p a r e d t o t he pa ra b o l i c t r o u g h an d ce n t ra l re ce i v e r s ys te ms (see F i g u r e 1 4); e ve n t h o u g h L F R s a re an i n he re n t l y l ess e f f i c i e n t c y c l e re q u i r i n g a l a r ge r c o l l e c t o r f i e l d.

1.2.4. D ish StirlingA so l a r d i s h s ys te m m a k es use o f S t i r l i n g en g i n e te c h n o l o g y (Reade r e t a l., 1 9 89) t o ge ne ra te e le c t r i c i t y. T h e S t i r l i n g d i s h te c h n o l o g y c o n v e r t s t he r m a l ene r g y t o e le c t r i c i t y b y us i n g a m i r r o r a r ray, shape d l i k e a sa te l l i t e d i s h (see F i g u r e 20), t o f o c u s l i g h t ra ys o n t he re ce i v e r en d o f a S t i r l i n g en g i n e; a s i n g l e a rea suspe n de d ab o v e t he b o w l o f m i r r o r s, w h e r e te m pe r a t u res u p t o 750° C hea t a t he r m a l f l u i d o r h y d r o ge n gas w h i c h e x pa n ds. T h e p r essu re c r ea te d b y t he e x pa n d i n g gas d r i v es a p i s t o n, c r a n k sha f t, an d d r i v e sha f t asse m b l y m u c h l i k e t h ose f o u n d i n i n te r n a l c o m b us t i o n en g i n es b u t w i t h o u t i g n i t i n g t he gas. T h e d r i v e sha f t t u r ns a s ma l l e le c t r i c i t y ge ne ra t o r. T h e en t i r e ene r g y c o n v e rs i o n p r o cess ta kes p l a ce w i t h i n a ca n i s te r t he s i ze o f an o i l ba r re l. T h e p r o cess r e q u i r es n o w a te r an d t he en g i n e i s e m i ss i o n-f r ee. I t i s en v i sa ge d t ha t a f i e l d o f d i s h S t i r l i n g s ys te ms m a y be use d as a p o w e r ge ne ra t i n g p l a n t (see F i g u r e 20).

Figure : The configuration of the dish Stirling system (Source: infiniacorp.com, stirlingenegy.com, and others, in Meyer, 2009)

1.2.5. C S P manufacturing researchF o r t he p u r p o se o f de v e l o p i n g t he S E T R M , an d t o c o ns i de r t he m a n u f a c t u r i n g i ssues an d asso c ia te i n t e r na t i o na l resea r c h f o c us a reas (see Ta b l es 9 an d 1 0), C SP s ys te ms a re d i v i d e d i n t o t he f o l l o w i n g te c h n o l o g y su bs ys te ms:

• Collection subsystem, c o ns is t i n g o f a:

o Reflector surface, w h i c h i s t y p i c a l l y m a de o f t h i c k g l ass s i l v e r m i r r o r s f o r m e d i n t o t he shape

o f a pa ra b o l a, i n t he case o f t he pa ra b o l i c t r o u g h o r d i s h S t i r l i n g s ys te ms, o r (near l y) f l a t, f o r t h e ce n t ra l r e ce i v e r s an d L i n ea r F r es ne l s ys te ms. A l t e r n a t i v e l y, m i r r o r s ca n be m a de f r o m t h i n g l ass, p l as t i c f i l m s o r p o l i s he d m e ta l s. N o n e re q u i r e m u c h f u r t h e r resea r c h.

o A n electronic control subsystem an d asso c ia te d m e c h a n i c a l d r i v e su bs ys te m t ha t a re

used t o o r i e n ta te t he re f l e c t o r su r f a ce. T h ese a re w e l l-es ta b l i s he d te c h n o l o g i es.

o A n absorber / receiver, which transfers received heat t o an o pe ra t i n g f l u i d ; f o r e xa m p l e, i n t he case o f t r o u g hs, t h r o u g h a g l ass en v e l o pe. T h e abso r be r i s c oa te d w i t h a se le c t i v e c oa t i n g t o m a x i m i ze ene r g y c o l l e c t i o n an d t o m i n i m i z e hea t l oss; m u c h resea r c h i s o n g o i n g i n t h i s a rea (Ken ne d y, 2002), an d su c h a spec t ra l l y se le c t i v e c oa t i n g has bee n pa te n te d at t he C S I R, an d is be i n g de v e l o pe d f o r so la r ap p l i ca t i o ns. T h e g l ass en v e l o pe hea ts o i l t o ab o v e 400 C. I n t he case˚ o f a ce n t ra l re ce i v e r t he c o n ce n t ra te d ra d i a t i o n m o s t o f te n f a l l s o n a t u be ba n k, t h r o u g h w h i c h f l o w s o ne o f t he f o l l o w i n g: sa t u ra te d w a te r an d stea m, su pe r hea te d stea m, o r m o l t e n sa l t. H e r e t he iss ue is t o ensu re t he t u be ba n k an d t he asso c ia te d w e l d i n g ca n su r v i v e t he r m a l t ra ns ie n ts as w e l l as n o n-u n i f o r m hea t i n g d ue t o t he c o m b i n a t i o n o f m a n y he l i o s ta t f o ca l r e g i o ns, o r “h o t sp o ts”. A l t e r n a t i v es t o t u be ba n ks a re o pe n an d c l ose d v o l u m e t r i c re ce i v e rs an d f a l l i n g pa r t i c l e re ce i v e r s.

T h e U n i t e d S ta tes i s i n v es t i g a t i n g t he l a t te r w h e re san d f a l l s t h r o u g h t he f o ca l sp o t an d is hea te d t o h i g h r e ce i v e r s ha v e bee n de ve l o pe d. I n t he case o f a so la r gas t u r b i n e t he c o n ce n t ra te d su n l i g h t (abo u t 500 su ns) m u s t be f u r t h e r c o n ce n t ra te d i n a c o m p o u n d sec o n da r y c o n ce n t ra t o r (CPC) t o ab o v e 1 ,000 su ns be f o re en te r i n g a c l ose d, p r essu r i sed v o l u m e t r i c re ce i v e r t h r o u g h a q ua r t z w i n d o w. O n l y I s rae l an d G e r m a n y ha ve b u i l t h i g h-f l u x C P C ’s o f t h i s na t u re, an d t he y r e q u i r e h i g h-pe r f o r m a n ce m i r r o r s t ha t ha v e ade q ua te rear-su r f a ce c o o l i n g t o c o n t r o l b o t h m i r r o r te m pe ra t u r e an d te m pe ra t u r e g r a d i e n t; a C P C w i t h a c o n ce n t ra t i o n ra t i o o f 1 6: 1 o f i s u n de r de v e l o p m e n t a t t he C S I R. O n ce t he ra d i a t i o n has passed t h r o u g h t he q ua r t z w i n d o w t he hea t i s abso r be d i n a m e ta l l i c o r ce ra m i c m es h. P ressu r i sed a i r passes t h r o u g h t he m es h an d i s t he re b y hea te d t o t he des i r e d te m pe ra t u r e. C e ra m i c s m a te r i a ls a re be i n g i n v es t i g a te d as t he r e ce i v e r m a te r i a l, i n p r e f e re n ce t o a m e ta l l i c m e sh, be ca use ce ra m i cs ha v e be t te r r es is ta n ce t o h i g h te m pe ra t u r es an d t o w e a t he r i n g (EC, 2004).

o Structure(s) to support the collector and its components are w e l l-es ta b l i s he d te c h n o l o g i es, t y p i c a l l y m a de o f m e ta l an d ce me n t t ha t h o l d t he c o m p o n e n ts i n ac c u ra te a l i g n me n t w h i l e res is t i n g t he e f f e c ts o f t h e w i n d. G l ass-re i n f o r c e d c o n c re te i s be i n g e x p l o re d i n he l i o s ta ts as an a l te r n a t i v e t o stee l t o re d u ce c os ts. T h e re l a t i v e c os ts o f s tee l an d ac t u a t o rs (as w e l l as w i n d l o a d i n g) ha v e l e d d i f f e re n t p l a ye rs t o ad o p t d i f f e re n t he l i o s ta t s i z i n g st ra te g ies: S E N E R, A b e n g o a, G e m aso l a r an d H i m i n (Ch i na) p re f e r l a r ge he l i o s ta ts (120 m 2, 1 20 m 2, 1 1 6 m 2an d 1 00 m 2r espe c t i v e l y), w h i l e eSo l a r, B r i g h t S o u r ce, S A I C an d T o k y o Te c h ha v e p u rs ue d m u c h s ma l l e r he l i o s ta t des i g ns (1. 14 m 2, 7.2 m 2, 1 0 m 2an d 8.5 m 2r espe c t i v e l y). T h e C S I R is de ve l o p i n g a 1 3 m 2ta r ge t-a l i g ne d he l i o s ta t w h i l e t he E s k o m des i g n i s t o be i n t he 1 20 m 2c lass.

• E nergy storage subsystem: R e ce n t p l a n ts st o re m o l t e n sa l t a t a h i g h te m pe r a t u re i n an i ns u l a te d tan k. T h e hea t f r o m t he sa l t ca n be use d a f te r su nse t t o ge ne ra te stea m. M o l t e n sa l t i s a c o m b i n a t i o n o f 60 % so d i u m n i t r a te an d 40 % p o tass i u m n i t r a te, an d is t he o n l y c o m m e r c i a l l y a va i l a b l e t he r m a l st o ra ge o p t i o n f o r l a r ge p l a n ts. I t has e x ce l l e n t hea t t ra ns f e r q ua l i t i es, c ha n ges f r o m so l i d t o l i q u i d a r o u n d 1 20 ° C t o 240° C, i t s o pe ra t i n g te m pe ra t u r es i s be t w ee n 500° C an d 600° C, an d is (cur re n t l y) l o w c os t. H o w e v e r, i t i s o n l y su p p l i e d f r o m C h i l e an d o t he r P hase C ha n ge M a t e r i a ls (PC M s) are be i n g i n v es t i ga te d (Pal g ra v e, 2008; W W G and M M A , 2008). I n ad d i t i o n, t he re a re v e r y f e w su p p l i e rs o f t he p u m ps re q u i r e d f o r m o l t e n sa l t; t h e y ha ve l o n g sha f t s an d m u s t o pe ra te i n a se ve re pe r pe t u a l te m pe r a t u re g r a d ie n t. O t h e r t he r m a l s t o ra ge o p t i o n s a re p re-c o m m e r c i a l sta ge o r s t i l l i n t he l a b o ra t o r y. D L R has suc cess f u l l y e x p l o r e d t he use o f c o n c r e te f o r h i g h te m pe r a t u re o i l pa ra b o l i c t r o u g h p l a n ts. T h e h i g h te m pe ra t u re a i r r e ce i v e r s ys te m a t Jü l i c h, G e r m a n y m a kes use o f a ce ra m i c t he r m o c l i n e s ys te m. L a t e n t hea t s t o ra ge f o r R a n k i n e s ys te ms us i n g n i t r a tes i s p r o m i s i n g i n t ha t s t o ra ge v o l u m e ca n be re d u ce d. R esea r c h i s o n g o i n g t o i n c rease t he e f f e c t i v e t he r m a l c o n d u c t i v i t y an d t he re f o r e t he c ha r ge an d d i s c ha r ge r a tes. T h e r m a l s t o ra ge f o r a so l a r gas t u r b i n e i s st i l l an o pe n q ues t i o n. C S I R i s i n v es t i g a t i n g a h i g h-te m pe ra t u re sens i b l e hea t pe b b l e-be d s ys te m w i t h a v i e w t o h i g h te m pe ra t u r e l a te n t hea t s t o ra ge i n t he f u t u re. G e n e ra l l y, t h e q ues t i o n i s n o t “ w ha t i s t he bes t s t o ra ge ap p r oa c h”, b u t ra t h e r “ w ha t i s t he bes t C SP p l a n t c o n ce p t i n c l u d i n g st o ra ge”. U n l i k e o t he r C SP k e y c o m p o n e n ts t he r m a l s t o ra ge is s t i l l a “s lee p i n g” m a r k e t; v e r y f e w c o m m e r c i a l su p p l i e rs e x i s t an d o p p o r t u n i t i es a re v e r y a t t r a c t i v e f o r m a r k e t en t ra n ts. S t r o n g R & D p r o g r a m m es e x i s t i n t he U S A , S pa i n, F r a n ce, G e r m a n y an d A u s t r a l i a.

• Power cycle subsystem : D i f f e r e n t c o o l i n g s ys te ms a re used as pa r t o f t he c o n v e n t i o na l p o w e r c y c l e. T o re d u ce t he w a te r usage o f t h e p l a n t (mo re t ha n 90 %), resea r c h e f f o r t s f o c us o n d r y-c o o l i n g (US D o E, 2008). U n f o r t u na te l y, d r y c o o l i n g c o mes a t t he c os t o f i n c r eased pa ras i t i c p o w e r an d re d u ce d pe r f o r m a n ce, i n c r eas i n g l e v e l i se d e le c t r i c i t y c os t. T h e so la r gas t u r b i n e, h o w e v e r, re q u i r es n o c o o l i n g w a te r. S o l a r gas t u r b i n es a re be i n g resea r c he d i n G e r m a n y, F r a n ce an d I s rae l. W h e n used i n a c o n v e n t i o na l c o m b i ne d c y c l e, t h e r esu l ta n t p l a n t has o ne-t h i r d t he c o o l i n g re q u i r e m e n t an d o ne an d a ha l f t i m es t he t he r m a l e f f i c i e n c y o f an eq u i v a l e n t so la r R a n k i n e p l a n t. C S I R is i n v es t i ga t i n g t he use o f a n o n-e le c t r i ca l b o t t o m i n g c y c l e (abso r p t i o n c h i l l e r o r t he r m a l desa l i n a t i o n p l a n t) i ns tea d, w h e re t he c o o l i n g w a te r r e q u i r e m e n t d i sa p pea rs. O t h e r e f f o r ts f o c us o n ad va n ce d p o w e r c y c l e i n t e g ra t i o n an d t he re d u c t i o n o f o pe ra t i n g an d m a i n te na n ce c os t.

Table : International research priorities for parabolic trough and central receiver CSPs (Source: US Do E, 2008)

Research effort Barrier addressed by research

Solar field technology

I m p r o v e nea r-te r m c o n c en t r a t o r c o m p o ne n t s an d s ys te m R e l i a b i l i t y an d o pe ra t i n g/ma i n te na n ce c os t

D e v e l o p ad v a n ced c o n ce n t r a t o r R e l i a b i l i t y an d o pe ra t i n g/ma i n te na n ce c os t

E v a l ua t e an d de m o ns t r a t e ad v a n ce d re ce i v e r tec h n o l o g i esPe r f o r m a n ce, o pe r a t i n g/ma i n te na n ce c os t an d tec h n o l o g y r i s k

Thermal energy storage technology

D e m o ns t r a t e i m p r o v e d near-te r m t he r m a l ener g y st o ra geR e l i a b i l i t y, pe r f o r m a n ce, o pe r a t i n g/ m a i n t e na n ce c os t an d tec h n o l o g y r i s k

C o n d u c t t he r m o c l i n e t he r m a l ener g y st o r a ge tes ts A b o v e near-te r m ba r r i e rs an d tec h n o l o g y r i s k

E v a l ua t e m o l t e n sa l t H T F/T ES Pe r f o r m a n ce an d o pe ra t i n g/ma i n t e na n ce c os t

A d v a n ce d H T F de ve l o p m e n ts Pe r f o r m a n ce an d o pe ra t i n g/ma i n t e na n ce c os t

Power cycle development

D e v e l o p d r y an d h y b r i d c o o l i n g s ys te ms Te c h n o l o g y r i s k

D e v e l o p an de m o ns t r a t e ad v a n ce d p o w e r c y c l e i n t e g r a t i o n O p e r a t i n g/ma i n te na n ce c os t

R e d u c e (and q ua n t i f y) o pe ra t i o n an d m a i n t e na n ce c os t T e c h n o l o g y r i s k

System integration

E x pa n d i n d us t r y sup p o r tPe r f o r m a n ce, o pe r a t i n g/ma i n te na n ce c os t an d tec h n o l o g y r i s k

D e v e l o p tes t i n g p r o t o c o l s an d i n d us t r y stan da r ds O p e r a t i n g/ma i n te na n ce c os t an d tec h n o l o g y r i s k

D e v e l o p an d v a l i da t e m o d e l l i n g an d ana l y s i s tec h n i q u es O p e r a t i n g/ma i n te na n ce c os t an d tec h n o l o g y r i s k

Ta b le 9 a ls o h i g h l i g h ts t ha t, i n te r n a t i o na l l y (US D o E, 2008; E U R E C, 2009), m u c h resea r c h i s gea re d t o w a r ds s ys te m i n te g r a t i o n i n o r de r t o ena b le t he c o m m e r c i a l i sa t i o n an d de p l o y m e n t o f t h e C SP s ys te ms. T h i s i s ec h oe d i n t he c u r re n t r esea r c h p r i o r i t i es f o r t h e d i s h S t i r l i n g C SP te c h n o l o g y (see Ta b l e 1 0). P i t z-Paa l e t a l. (2005) est i m a te L E C re d u c t i o n s f o r v a r i o us r esea r c h p r i o r i t y a reas; t he l a r g es t re d u c t i o n s a re asso c ia te d w i t h t he st r u c t u r es an d asse m b l i es o f t he c o n ce n t ra t o r s.

Table: I nternational research priorities for the dish Stirling C S P

Research effort Barrier addressed by research

D ish concentrator

D e v e l o p ad v a n ce d d i s h st r u c t u r e des i g n R e l i a b i l i t y an d o pe r a t i n g/ma i n t e na n ce c os t

D e v e l o p i m p r o v e d az i m u t h d r i v e R e l i a b i l i t y an d tec h n o l o g y r i s k

D e s i g n ne w o p t i ca l e le me n t s R e l i a b i l i t y, o pe ra t i n g/ma i n t e na n ce c os t an d tec h n o l o g y r i s k

Power conversion unit

D e v e l o p ne x t-ge ne r a t i o n P C U des i g nR e l i a b i l i t y, pe r f o r m a n ce, o pe ra t i n g/ m a i n t e na n ce c os t an d tec h n o l o g y r i s k

D e v e l o p ad v a n ce d D I R re ce i v e r R e l i a b i l i t y, pe r f o r m a n ce an d tec h n o l o g y r i s k

System engineering and integration

S y s te m r e l i a b i l i t y i m p r o v e m e n t R e l i a b i l i t y, pe r f o r m a n ce an d tec h n o l o g y r i s k

D e v e l o p s i m u l a t i o n an d des i g n t o o l s O p e r a t i n g/ma i n t e na n ce c os t an d tec h n o l o g y r i s k

D e v e l o p ne x t-ge ne r a t i o n c o n t r o l sPe r f o r m a n ce, o pe ra t i n g/ma i n t e na n ce c os t an d tec h n o l o g y r i s k

A d d r ess B O P issuesR e l i a b i l i t y, pe r f o r m a n ce, o pe ra t i n g/ m a i n t e na n ce c os t an d tec h n o l o g y r i s k

Deployment facilitation (all CS P systems)

Pe r f o r m m a r k e t ana l y s i s an d sup p o r tR e l i a b i l i t y, i n s ta l l e d s ys te ms an d o pe ra t i n g/ma i n te na n ce c os t

S u p p o r t o u t r eac h t o g o v e r n m e n t an d sta ke h o l d e r sR e l i a b i l i t y, i n s ta l l e d s ys te ms an d o pe ra t i n g/ma i n te na n ce c os t

1.3. Non-concentrating solar thermal systems

1.3.1. Solar chimneyT h e so la r c h i m n e y o r u p d r a f t t o w e r c o m b i n es t h ree o l d an d p r o v e n te c h n o l o g i es: t h e c h i m n e y e f f e c t; t he g r ee n h o use e f f e c t; an d t he w i n d t u r b i n e. A i r i s hea ted b y su ns h i n e an d c o n t a i ne d i n a v e r y l a r g e g r ee n h o use-l i k e st r u c t u r e a r o u n d t he base o f a ta l l c h i m n e y, an d t he resu l t i n g c o n v e c t i o n ca uses r i s i n g a i r f l o w t o r i se t h r o u g h t he u p d r a f t t o w e r (see F i g u r e 2 1). T h e a i r c u r re n t f r o m t he g r ee n h o use u p t he c h i m n e y d r i v es t u r b i n es, w h i c h p r o d u ce e le c t r i c i t y. A suc cess f u l resea r c h p r o t o t y pe o pe ra te d i n S pa i n i n t he 1 9 80s, an d m a n y m o de l l i n g st u d i es ha v e bee n p u b l i s h e d as t o o p t i m i z a t i o n, sca le, an d ec o n o m i c f eas i b i l i t y (e.g. V o n B a c ks t r ö m an d G a n n o n, 2000). T h e ge ne ra t i n g ab i l i t y o f a so l a r u p d r a f t p o w e r p l a n t de pe n ds p r i m a r i l y o n t w o f a c t o r s: t he s i ze o f t h e c o l l e c t o r a rea an d c h i m n e y he i g h t. W i t h a l a r ge r c o l l e c t o r a rea, a g r ea te r v o l u m e o f a i r i s w a r m e d t o f l o w u p t he c h i m n e y; c o l l e c t o r a reas as l a r g e as 7 k m i n d i a m e te r ha v e bee n c o ns i d e re d. W i t h a l a r ge r c h i m n e y he i g h t, t he p r essu re d i f f e re n ce i n c r eases t he stac k e f f e c t; c h i m n e ys h i g he r t ha n 1 ,000 m ha v e bee n i n v es t i g a te d (Ho l m a n, 2009). T o c o m p e nsa te f o r t he h i g h c os t (and r i s k) t o c o ns t r u c t a so l i d c h i m n e y st r u c t u re, resea r c h e f f o r ts a re gea re d t o w a r ds n o v e l des i g ns suc h as t he f l o a t i n g so l a r c h i m n e y (see F i g u r e 22). T h e b o d y o f t h e f l o a t i n g so la r c h i m n e y is m a de o f su ccess i v e t o r o i d a l t u bes f i l l e d w i t h l i g h t e r t ha n a i r gas su c h as he l i u m o r n i t r o ge n (Papage o r g i o u, 2008).

Figure: The solar chimney, solar updraft tower or aero power plant (Source: desertec-africa.org)

Figure : The floating solar chimney concept (Source: floatingsolarchimney.gr)

1.3.2. Solar pondsT h e l eas t e x pe ns i v e t y p e o f so la r c o l l e c t o r ap pea rs t o be a l a r ge so la r p o n d (St i ne an d G e ye r, 200 1); t he l o w e r c os t f o r su c h a s ys te m c o m pe nsa tes f o r t he re la t i v e l y l o w e f f i c i e n c i es o f t h ese s ys te ms. H o w e v e r, t he y ha v e bee n c o ns i d e re d p r i m a r i l y f o r l a r ge i n d us t r i a l ap p l i ca t i o ns be ca use t he i r c os t de c r eases c o ns i d e ra b l y w i t h i n c r eases i n s i ze. T h e re a re t w o bas i c t y pes o f so la r p o n ds: t he sha l l o w p o n d an d t he sa l t-g r a d i e n t p o n d. B o t h a re eq u i v a l e n t t o h o r i z o n ta l f l a t-p l a te c o l l e c t o r s, s i n ce t he y a re n o n-c o n ce n t ra t i n g, ac ce p t b o t h d i r e c t an d d i f f u se so la r ene r g y, an d a re l i m i t e d t o l o w te m pe ra t u r e ap p l i c a t i o n s.

A sha l l o w so la r p o n d c o ns is ts o f a g r o u p o f c o l l e c t o rs m a de o f b l a c k p l as t i c l i n e rs l y i n g o n t o p o f i n s u la t i o n t ha t has bee n l a i d o n f l a t g ra de d g r o u n d. A b o v e t he w a te r ba g is a t l eas t o ne t ra ns l u ce n t c o v e r shee t, su p p o r te d b y s i de c u r bs. W h e n t he re i s ade q ua te su ns h i n e, w a te r i s p u m pe d i n t o t he c o l l e c t o r s f r o m an u n de r g r o u n d st o ra ge ta n k. T h e w a te r i ns i d e t he c o l l e c t o r s i s hea ted b y so la r ra d i a t i o n abs o r be d b y t he p o n d l i n e r an d ca n at ta i n te m pe ra t u r es o f u p t o 60º C (140ºF). O n ce hea te d, t he w a te r i n t he c o l l e c t o rs m a y be p u m pe d t o an i n d us t r i a l de ma n d o r a h o t s t o ra ge tan k f o r l a te r use. A t n i g h t o r d u r i n g pe r i o ds o f l o w so la r i r r a d i a n ce, t he w a te r i n t he c o l l e c t o r s m a y be d ra i n e d ba c k i n t o t he u n de r g r o u n d ta n k, t he re b y c o nse r v i n g t he hea t c o l l e c te d. F i g u re 23 sh o w s a sha l l o w p o n d c o l l e c t o r des i g n f o r use i n a l o w-te m pe ra t u r e so la r t he r m a l p o w e r s ys te m. T h e c o l l e c t o r m o d u l es a re 4 m (14 f t) w i d e an d 200 m (656 f t) l o n g. T h e w i d t h i s de te r m i ne d b y t he w i d t h o f c o m me r c i a l l y a va i l a b l e u nsea me d, w e a t he ra b l e p l as t i c shee ts.

Figure : A shallow solar pondcollector (Source: D ickenson et al., 1976)

A n o pe n b o d y o f w a te r abso r bs so la r ene r g y, w h i c h c r ea tes c o n v e c t i o n c u r re n ts. A s t he su n r a ys t ha t pass t h r o u g h t he su r f a ce l a y e r a re abso r be d i n l o w e r l a ye rs, t h i s w a te r i s hea te d an d r i ses t o t he su r f a ce, w h e re hea t i s

t r a ns fe r re d a w a y b y c o n v e c t i o n t o a m b i e n t a i r. O n c e t he w a te r c o o l s, t he de ns i t y i n c r eases an d t he su r f a ce w a te r m o v es d o w n w a r d. T h i s m o v e me n t o f w a te r eq ua l i z es t he te m pe ra t u re t h r o u g h o u t t he b o d y o f w a te r. A sa l t-g r a d i e n t so l a r p o n d e m p l o y s a sa l t c o n ce n t ra t i o n g ra d i e n t t o su p p r ess na t u r a l c o n v e c t i o n. H e a te d w a te r h o l ds m o r e d i ss o l v e d sa l t t ha n d oes c o o l e r w a te r. T h e sa l t y, hea ted w a te r i s a ls o hea v i e r an d t h us r e ma i ns a t t h e b o t t o m o f t he so l a r p o n d. S u n l i g h t pe ne t ra t i n g t h r o u g h t he t o p l a y e rs o f t he p o n d is abs o r be d at t he b o t t o m an d t ra p pe d b y t he n o n-c o n v e c t i n g g r a d i e n t l a y e r, w h i c h ac ts as an e f f e c t i v e t he r m a l i n s u la t o r aga i ns t c o n v e c t i o n.

I n p r a c t i ce, sa l t-g r a d i e n t so la r p o n ds c o ns is t o f t h r ee l a y e rs, o r z o nes (see F i g u r e 24):

• A su r f a ce c o n v e c t i n g z o ne o f l o w-sa l i n i t y w a te r, t y p i ca l l y 0.2-0.4 m (8-1 6 i n.) t h i c k, na me l y an u p pe r c o n v e c t i v e z o ne (UC Z);

• A n o n-c o n v e c t i n g o r sa l i n i t y-g r a d i e n t z o ne (NC Z) be nea t h t he su r f a ce z o ne, i n w h i c h sa l t c o n ce n t ra t i o n i n c reases w i t h de p t h, t y p i c a l l y 1 .0-1 .5 m (3.3-5 f t) t h i c k ; an d

• A st o ra ge z o ne a t t h e b o t t o m o f t he p o n d o f u n i f o r m l y h i g h sa l t c o n ce n t ra t i o n t ha t s t o res hea t an d is t y p i c a l l y 1-3 m (3.3-1 0 f t) t h i c k, na me l y a l o w e r c o n v e c t i v e z o ne (LC Z) (Ku r t e t a l., 2000; V e l m u r u ga n an d S r i t h a r, 2008).

Figure : Variation of salinity, temperature and density with depth (Source: Velmurugan and Srithar, 2008)

F o r u t i l i z a t i o n o f t he hea t s t o re d at t he b o t t o m o f t he p o n d, h o t b r i n e i s d ra w n f r o m t he st o ra ge z o ne (bot t o m l a y e r) o f t he p o n d an d p u m p e d t h r o u g h a hea t e x c ha n ge r an d bac k t o t he b o t t o m o f t he st o ra ge z o ne. F o r p o w e r p r o d u c t i o n ap p l i c a t i o n s w h e r e a R a n k i n e c y c l e i s used, c o n de nse r c o o l i n g w a te r i s d ra w n o f f t he t o p o f t he p o n d an d passed t h r o u g h t he c o n de nse r an d ba c k t o t he su r f a ce, w h e r e i t c o o l s.

A sa l t-g ra d i e n t so la r p o n d ca n p r o v i d e hea t a t te m pe ra t u res i n e x cess o f 90ºC (194ºF). S u c h a p o n d p r o v i d es b u i l t-i n t he r m a l st o ra ge o f su c h l a r ge v o l u m e t ha t hea t ca n be c o l l e c te d i n t he su m me r an d st o re d f o r use d u r i n g t he w i n t e r.

C o ns t r u c t i o n o f ec o n o m i ca l so la r p o n ds re q u i r es t he a va i l a b i l i t y o f i n e x pe ns i v e, f l a t l a n d; access i b i l i t y t o w a te r; an d an i ne x p e ns i v e so u r ce o f sa l t o r b r i n e. A t y p i c a l a r ra n ge me n t f o r t h i s p r o cess i s sh o w n i n F i g u r e 25, an d i t has bee n f o u n d t o be su i ta b l e f o r r u ra l a reas i n de ve l o p i n g c o u n t r i es.

Figure : E lectrical power production concept using salt-gradient ponds

2. Thermal heating and cooling applicationsA s i n d i c a te d i n sec t i o n 1 . 1 (and Ta b l es 1 an d 2), t he r m a l hea t i n g an d c o o l i n g ap p l i c a t i o ns r e f e r t o p r o v i s i o n o r re m o v a l o f hea t, t h e u n i t o f w h i c h i s de g r ees C e l s i us (ºC) o r K e l v i n (K). I n 2006, t he m o s t c o m m o n c o l l e c t o r s i n use w e r e w a te r-based f l a t p l a te c o l l e c t o r s an d e va c ua te d t u be c o l l e c t o rs (ES T I F, 2006), an d is p r o ba b l y s t i l l t r u e i n 20 10. T h ese c o l l e c t o r s ha ve u n de r g o ne a g r ea t dea l o f de v e l o p m e n t o v e r t he l as t f e w de ca des an d a re t y p i c a l l y v e r y e f f i c i e n t, u s i n g se le c t i v e c oa te d abs o r be rs, an d h i g h l y t ra ns m i ss i v e g l ass, so me t i m es i n c o n ne c t i o n w i t h an t i-re f l e c t i v e c oa t i n g s. T h ese c o l l e c t o r s w o r k v e r y e f f e c t i v e l y u p t o 80° C an d a re f r e q ue n t l y used i n so la r hea t f o r i n d u s t r i a l p r o cesses (SH I P) ap p l i c a t i o n s (ES T I F, 2006). Ta b l e 1 1 p r o v i d es a ra n ge o f i n d us t r i a l p r o cesses w i t h t he c o r res p o n d i n g re q u i r e d te m pe r a t u re ra n ges (ES T I F, 2006), w h i l e Ta b l es 1 2 an d 1 3 l i s t desa l i n a t i o n an d c h i l l e r te c h n o l o g i es, w h i c h ca n be d r i v e n b y so la r hea t (RE N A C, 2009). P r o cesses i n t he te m pe ra t u r e r a n ge o f e x i s t i n g c o l l e c t o r s a re u n de r l i n e d i n Ta b l es 1 1 t o 1 3, w h i l e t h ose i n t he ra n ge o f ad va n ce d f l a t p l a te c o l l e c t o r s (up t o 1 20 ° C) are i n i t a l i c s. T h e o t he r p r o cesses a re ab o v e t hese te m pe ra t u re r a n ges an d re q u i r e m o r e ad v a n ce d c o l l e c t o r s.

Table : I ndustrial sectors / processes with the greatest potential for solar thermal uses (Source: EST IF, 2006)

I ndustrial sector P rocess Temperature level °C

F o o d an d be ve r a ges D r y i n g

W as h i n g

PasteurisingBoilingS te r i l i s i n g

H e a t t r ea t me n t

30 – 90

40 – 80

80 – 1 1 0

95 – 1 05

1 40 – 1 50

40 – 60

Te x t i l e i n d us t r y W as h i n g

BleachingD y e i n g

40 –80

60 – 1 00

1 00 – 1 60

C h e m i ca l i n d us t r y BoilingD i s t i l l i n g

V a r i o us c he m i ca l p r o cesses

95 – 1 05

1 1 0 – 300

1 20 - 1 80

A l l sec t o r s pre-heating of boiler feed waterhea t i n g o f p r o d u c t i o n ha l l s

30 – 1 00

30 – 80

Table : Desalination processes using thermal energy (Source: R E NAC, 2009)

P rocessTemp.Level

°C

ThermalEnergy

k W th/ m 3

Electrical energy

k W el/ m 3

B rine / product

Water cost

$ / m 3

P lant cost $ /m 3day Comments

M u l t i-E f f e c t D e sa l i na t i o n (ME D)

<70 2 1 1 .5-2.5 4-9 0.7-1 .0 900-1 700S ma l l e r v o l u m es t ha n M S F

Multi-Stage Flash (MSF)

90-1 20 704 3-4 0.9-1 . 1 1 000-1 500 r o b us t

M e m b r a ne D i s t i l l a t i o n

50-90 ? 0 ? ? ?R e q u i r es c o o l i n g st r ea m

R e v e r se O s m os i s (for c o m pa r i s o n)

- - 4-5 1-4 0.6-1 .2 900-1 500

M a i n t e na n ce i n t e ns i v e

- c he m i c a l s

- s k i l l e d sta f f

Table : Chilling processes using thermal energy (Source: R E NAC, 2009)

P rocessDriving

Temperature°C

CO P Size range Sorbent Comments

Absorption (1 stage) 75 – 1 1 5 0.6-0.75 50 k W – 5 M W L i q u i d

(e.g. L i-B r)Te c h n i ca l l y m a t u r eA b s o r p t i o n (2 stage) 1 30 – 1 80 1-1 .3 50 k W – 5 M W

A d s o r p t i o n 60 – 90 0.3-0.7 70 – 1 050 k WSo l i d (e.g. s i l i c a ge l)

L t d n o o f sup p l i e r s

A s ca n be seen i n Ta b l es 1 1 t o 1 3, S H I P ap p l i ca t i o ns o f te n re q u i r e te m pe ra t u res f r o m 80° C t o 250° C, w h i c h re q u i r e m e d i u m te m pe ra t u r e c o l l e c t o r s, o f w h i c h o n l y f e w a re a va i l a b l e i n t he m a r k e t t o da y an d w h i c h nee d f u r t h e r o p t i m i sa t i o n an d de v e l o p m e n t. T h i s i s w h y t he I n te r na t i o na l E n e r g y A g e n c y 's S o l a r H ea t i n g an d C o o l i n g (IE A-S H C) p r o g r a m m e de v e l o ps an d tes ts d i f f e re n t ca te g o r i es o f m e d i u m te m pe ra t u r e c o l l e c t o r s as pa r t o f t h e i r Tas k 33: n o n-t ra c k i n g, i m p r o v e d f l a t p l a te c o l l e c t o r s; e va c ua te d t u be c o l l e c t o r s; c o n ce n t ra t i n g f l a t p l a te c o l l e c t o r s; an d o t her, m o r e h i g h l y, c o n ce n t ra t i n g c o l l e c t o r s w i t h t ra c k i n g. I n te r ms o f t he l a t te r, h i g he r te m pe ra t u r e ap p l i ca t i o ns a re a ls o p oss i b l e f o r f u r n a ces, gas i f i c a t i o n o r t he r m o c he m i c a l p r o cesses.

2.1. Non-tracking, improved flat plate collectorsF l a t-p l a te c o l l e c t o r s use b o t h bea m an d d i f f u se so la r ra d i a t i o n, d o n o t r e q u i r e t ra c k i n g o f t he su n, an d a re l o w-m a i n te na n ce, i n e x pe ns i v e an d m e c h a n i c a l l y s i m p l e (We iss an d R o m m e l, 2008). T h ese ap p l i ca t i o ns a re t y p i c a l l y asso c i a te d w i t h (re la t i v e l y) l o w te m pe ra t u r e p r o v i s i o n (see Ta b l e 2), e.g. t he c o n v e n t i o na l so la r d o mes t i c w a te r hea te r (D W H) (see F i g u r e 26).

Figure : Conventional solar water heaters in South Africa (Source: csir.co.za /energyfutures)

So l a r ra d i a t i o n en te rs t he c o l l e c t o r t h r o u g h t he t ra ns pa re n t c o v e r an d rea c hes t he abs o r ber. H e r e t he abso r be d ra d i a t i o n i s c o n v e r te d t o t he r m a l ene r g y. A g o o d t he r m a l c o n d u c t i v i t y i s nee de d t o t ra ns fe r t h e c o l l e c te d hea t f r o m t he abs o r be r shee t t o t he abs o r be r p i p es w h e r e t he hea t i s f i n a l l y t ra ns fe r re d t o t he f l u i d. U s u a l l y a w a te r/g l y c o l m i x t u r e w i t h an t i c o r r os i o n ad d i t i v es i s used as t he hea t ca r r y i n g f l u i d. T h e f l u i d a ls o p r o te c ts t he c o l l e c t o r f r o m f r o s t da ma ge. T o i m p r o v e stan da r d f l a t-p l a te c o l l e c t o rs so me o f t he m a i n l osses nee d t o be re d u ce d (see F i g u r e 27). T h ese l osses ca n be c l ass i f i e d i n o p t i c a l an d t he r m a l l o sses. T h e t he r m a l l o sses r a p i d l y i n c r ease w i t h h i g he r te m pe ra t u r es, w h i l e t he o p t i c a l l o sses a re c o ns ta n t.

Figure : M ain losses of a basic flat-plate collector during angular operation (Source: Heß and Rommel, in Weiss and Rommel, 2008)

2.1.1. Optical lossesH i g h q ua l i t y c o v e rs o f l o w-i r o n so la r g l ass ha ve a t ra ns m i ss i o n o f 90 % f o r so la r ra d i a t i o n (nor ma l i r r a d ia t i o n). I f an an t i-re f l e c t i v e c oa t i n g i s used t he t ra ns m i ss i o n ca n be i n c r eased t o 93 t o 96 %. U s u a l l y ab o u t 1 t o 2 % is abso r be d i n t he g l ass p l a ne an d t he res t i s l os t d ue t o re f l e c t i o n. T h e c oa t i n g o f t h e abs o r be r ca n rea c h abs o r p t i o n c oe f f i c i e n ts o f 95 %. T h e o p t i ca l l osses g r o w w i t h i n c reas i n g an g l es o f t h e i n c i d e n t su n l i g h t.

2.1.2. Thermal lossesT h e m a i n t he r m a l l osses at t h e f r o n t a re ca use d b y c o n v e c t i o n. T h e c i r c u l a t i n g a i r be t w ee n abso r be r an d c o v e r t ra nsp o r t s t h e abs o r be d hea t t o t he g l a z i n g. A f t e r hea t c o n d u c t i o n t h r o u g h t he c o v e r t he re i s aga i n c o n v e c t i v e l oss be ca use o f t he a i r t h a t f l o w s a r o u n d t he c o l l e c t o r. T h e h o t abso r be r a ls o r a d ia tes i n f r a re d ra d i a t i o n t o t he c o v e r, f r o m w h e r e t he hea t i s t ra ns fe r re d t o t he en v i r o n me n t. T h e I R-e m i t ta n ce o f a se le c t i v e abs o r be r ca n rea c h d o w n t o 5 %. A t t he ba c ks i d e, t he r m a l l o sses o c c u r a t t he i ns u l a t i o n. T h e hea t c o n d u c t i o n t he re de pe n ds o n t he used m a te r i a l an d ca n be k e p t l o w b y us i n g t he r m a l i n s u la t i o n o f ade q ua te t h i c k ness. F o r a s i n g l e g l a ze d f l a t-p l a te c o l l e c t o r w i t h a se le c t i v e c oa te d abso r be r o n l y ab o u t o ne-se ve n t h o f t h e t o ta l hea t l osses o c c u r a t t he rea r s i de.

2.1.3. Construction principleA d v a n ce d f l a t-p l a te c o l l e c t o r s d i f f e r l i t t l e f r o m stan da r d f l a t-p l a te c o l l e c t o rs. T h e m a i n e le m e n ts a re (see F i g u r e 28):

Figure : B asic flat-plate collector for applications up to 80ºC (Source: Heß and Rommel, in Weiss and Rommel, 2008)

• Transparent cover: T o assu re h i g h t ra ns m i t t a n ce an d h i g h d u ra b i l i t y, c o v e rs o f l o w i r o n, te m pe re d so la r g l ass w i t h an t i r e f l e c t i v e c oa t i n g a re use d. I f a sec o n d o r t h i r d t ra nspa re n t c o v e r i s use d, t he y a re m a de o f an t i-r e f l e c t i v e c oa te d g l ass o r Te f l o n f i l m s. K e y f a c t o r s a re h i g h t ra ns m i ss i v i t y, h i g h te m pe ra t u r e sta b i l i t y, an d l o w hea t e x pa ns i o n.

• Absorber: T h e m o s t c o m m o n m a te r i a l f o r shee t an d abso r be r p i p es i s c o p pe r; h o w e v e r, shee ts o f a l u m i n i u m a re a ls o use d d ue t o t he i r l o w e r c os ts. F o r c o r r os i v e ap p l i c a t i o ns, s ta i n l ess stee l i s a p oss i b l e m a te r i a l. T h e sta te-o f-t he-a r t i s a se le c t i v e c oa t i n g o n t he shee t t o re d u ce t he t he r m a l l o sses d ue t o i n f r a re d ra d i a t i o n. T h e abso r be r p i p e w o r k sh o u l d be des i g ne d t o ens u re h i g h hea t t ra ns fe r. W i t h re ga r d t o sta g na t i o n, t he h y d r a u l i c abso r be r sh o u l d be des i g ne d t o a l l o w a f l u i d e m p t y i n g be ha v i o u r w h e n stea m o c c u rs u n de r s ta g na t i o n c o n d i t i o ns.

• I nsulation: D u e t o t he h i g h te m pe r a t u res m i n e r a l w o o l o r r o c k w o o l i s o f te n use d as i ns u l a t i o n m a te r i a l t o re d u ce t he t he r m a l l osses o n t he ba c ks i d e o f t h e abso r ber. I n so me c o n f i g u r a t i o n s ad d i t i o na l p o l y u r e t ha ne p l a tes a re used be t w ee n t he i n s u la t i o n m a t an d t he rea r pa ne l o f t he c o l l e c t o r.

• Casing: T h e cas i n g ens u res sta b i l i t y an d p r o te c ts t he abs o r be r an d t he i n s u l a t i o n aga i ns t en v i r o n me n ta l i m p a c ts. I t o f t e n c o ns is ts o f a l u m i n i u m, stee l, w o o d o r s y n t h e t i c m a te r i a l. T h e f r a m e pa r ts ca n be b r a ze d, r i v e te d o r g l u e d. S o m e f r a m es a re f o r m e d as a t ra y so t ha t a c o n ne c t i o n i s n o t nee de d be t w ee n t he s i de p l a tes an d rea r pa ne l.

2.1.4. Current stage of developmentW i t h sta n da r d f l a t-p l a te c o l l e c t o r s o pe ra t i o n te m pe ra t u res u p t o 80° C ca n be rea c he d. B e ca use o f i ts h i g h hea t l osses, t he bas i c f l a t-p l a te c o l l e c t o r has t o be i m p r o v e d t o ec o n o m i ca l l y c o v e r t he l o w e r m e d i u m te m pe r a t u re l e v e l u p t o 1 50 ° C.

T o i m p r o v e t he h o t w a te r te m pe ra t u r e ac h i e v a b l e f r o m f l a t p l a te c o l l e c t o r s f r o m m a x i m u m 80° C t o t he 80-1 20 ° C ra n ge, t he t he r m a l l osses o f t he c o l l e c t o r m u s t be re d u ce d w i t h o u t l o s i n g t o o m u c h o p t i ca l e f f i c i e n c y. T h i s w o u l d a l l o w t he m t o pe r f o r m t h ose so la r p r o cess hea t p r o cesses i n i ta l i cs i n Ta b l es 1 1 t o 1 3. T h i s r i se i n ac h i e v a b l e te m pe ra t u re ca n be ac h ie ve d b y t he f o l l o w i n g i m p r o v e m e n ts (ES T I F, 2006, W e i ss an d R o m m e l, 2008):

• M u l t i p l e g l a z i n g w i t h an t i-re f l e c t i v e g l ass;

• F i l l i n g a he r m e t i c a l l y sea le d f l a t p l a te c o l l e c t o r w i t h a n o b l e o r i n e r t gas;

• E v a c ua t i n g a he r m e t i c a l l y sea le d f l a t p l a te c o l l e c t o r; an d

• C o m b i n a t i o n s o f t he ab o v e.

F i g u r e 29 sh o w s t he e f f i c i e n c y c u r v es f o r s i n g l e, d o u b l e an d t r i p l e-g l a ze d c o l l e c t o rs c o v e re d w i t h ne w l y de v e l o pe d an t i-re f l e c t i v e g l a z i n g (“A R-g l ass”). I n ge ne ra l, f o r a l l ap p l i c a t i o n s nee d i n g so la r p r o cess hea t a t l e v e l s u p t o 1 20 ° C, ad va n ce d f l a t p l a te c o l l e c t o rs ha ve ec o n o m i ca l be ne f i t s c o m p a r e d t o c o n ce n t ra t i n g so la r s ys te ms, espec ia l l y t he case f o r c l i m a tes w i t h a h i g h p r o p o r t i o n o f d i f f u se ra d i a t i o n (We iss an d R o m m e l, 2008). T h i s i s pa r t i c u l a r l y ap p l i ca b l e t o i n d us t r i es i n M p u m a l a n ga, K w a Z u l u-N a ta l, E as te r n C a pe o r t he so u t he r n rea c hes o f t h e W es te r n C a pe, f o r e xa m p l e; w h e r e c l o u d c o v e r re d u ces t he d i r e c t n o r m a l i n s o la t i o n (D N I), w h i c h t ra c k i n g c o n ce n t ra t i n g s ys te ms re l y o n e x c l u s i v e l y t o t he e x c l us i o n o f d i f f u se ra d i a t i o n.

Figure : Comparison of the efficiency curves for a standard flat-plate collector (normal solar glass) and the curves for single double and triple- anti-reflective ( A R ) glazed collectors

(G=800 W / m² (Source: Rommel, Fraunhofer I S E, reproduced in EST IF, 2006)

2.2. Evacuated tube collectorsT h e re a re se ve ra l t y pes o f e vac ua te d t u bes i n use f o r so la r c o l l e c t o r s. T h e S y d n e y t u be (also k n o w n as “ t w i n-g l ass t u be” o r “ t he r m o s f l as k t u be”), sh o w n i n F i g u r e 30 is a p o p u l a r c o l l e c t o r t y p e.

Figure : B asic elements of a S ydney tube collector (left and centre), vacuu m error indication (right)

(Source: Heß and Rommel, in Weiss and Rommel, 2008)

T h e d i f f e r e n t t y pes o f e va c ua te d t u be c o l l e c t o r s ha v e s i m i l a r te c h n i c a l a t t r i b u tes:

• A c o l l e c t o r c o ns is ts o f a r o w o f pa ra l l e l g l ass t u bes.

• A v a c u u m (<10-2 Pa) i ns i d e e ve r y s i n g l e t u be g r ea t l y re d u ces c o n d u c t i o n l o sses an d e l i m i n a tes c o n v e c t i o n l osses.

• T h e f o r m o f t he g l ass i s a l w a y s a t u be t o w i t h s ta n d t he st ress o f t h e v a c u u m.

• T h e u p pe r en d o f t he t u bes is c o n nec te d t o a hea de r p i p e.

T h e ge t te r i s an o t he r c o m p o ne n t e va c ua te d t u bes ha ve i n c o m m o n. I t i s used t o m a i n t a i n t he v a c u u m i ns i d e. D u r i n g t he m a n u f a c t u r i n g o f m o s t e va c ua te d t u bes t he ge t te r i s i n d u c t i v e l y e x p osed t o h i g h te m pe ra t u r es. T h i s ca uses t he b o t t o m o f t he e vac ua te d t u be t o be c oa te d w i t h a p u r e l a y e r o f ba r i u m. T h i s ba r i u m l a y e r e l i m i n a tes an y C O, C O 2, N 2, O 2, H 2O an d H 2o u t-gassed f r o m t he e vac ua te d t u be d u r i n g st o ra ge an d o pe ra t i o n. T h e ba r i u m l a y e r a ls o p r o v i d es a c lea r v i s ua l i n d i c a t o r o f t he v a c u u m sta t us. T h e s i l v e r c o l o u r e d ba r i u m l a ye r w i l l t u r n w h i t e i f t he v a c u u m is e ve r l os t. T h i s m a k es i t eas y t o de te r m i n e w h e t he r o r n o t a t u be i s i n g o o d c o n d i t i o n (see F i g u r e 30, o n t he r i g h t).

E v a c ua te d t u be c o l l e c t o r s ca n be c l ass i f i e d i n t w o m a i n g r o u ps:

• D i r e c t f l o w t u bes: T h e f l u i d o f t h e so la r l o o p is a ls o c i r c u l a te d t h r o u g h t he p i p i n g o f t he abso r ber.

• H ea t p i p e t u bes: T h e abso r be d hea t i s t ra ns f e r re d b y us i n g t he hea t p i p e p r i n c i p l e w i t h o u t d i r e c t c o n t a c t t o t he hea t t ra ns fe r f l u i d o f t he so la r l o o p.

2.2.1. D irect flow evacuated tube collectorsI f a s i n g l e e vac ua te d g l ass t u be is use d t he w h o l e i n t e r i o r i s e va c ua te d. F o r t h i s c o n f i g u r a t i o n t he f l a t o r c u r v e d abso r be r as w e l l as f l u i d i n l e t an d f l u i d o u t l e t p i p es a re i ns i d e o f t he v a c u u m. T h e abs o r be r i s c oa te d w i t h a se le c t i v e su r f a ce. S i n g l e e vac ua te d t u bes o f te n ha ve d i a me te rs be t w ee n 70 an d 1 00 m m (see F i g u r e 3 1).

Figure: Sectional drawing of a direct flow pipe with flat absorber and u-tube (left), Letz tube (right)

(Source: Heß and Rommel, in Weiss and Rommel, 2008)

T h e t u bes a re d i v i d e d b y c o n f i g u r a t i o n o f t he f l u i d p i p es. T h e t ra d i t i o na l t y p e i s a c o l l e c t o r w i t h sepa ra te d t u bes f o r f l u i d i n l e t an d f l u i d o u t l e t (ind i ca te d i n F i g u r e 3 1). B es i d es t h i s t y pe, c o l l e c t o rs w i t h c o n ce n t r i c i n l e t an d o u t l e t p i p es a re a ls o m a n u f a c t u r e d (see F i g u r e 3 1, r i g h t). T h i s m ea ns t ha t o n l y t he f l u i d o u t l e t p i p e i s c o n ne c te d t o t he abso r ber. T h e p i p e f o r f l u i d i n l e t i s l o ca te d i ns i d e t he o u t l e t p i p e. T h e f l u i d f l o w s bac k be t w ee n t he o u t e r su r f a ce o f t h e i n ne r p i p e an d t he i n ne r su r f a ce o f t h e o u t e r p i p e. T h e ad v a n ta ge o f t h i s c o ns t r u c t i o n i s r o ta t i o na l s y m m e t r y. T h i s o f f e r s t he p oss i b i l i t y t o o p t i o na l l y o r i e n ta te t he abso r be r b y r o ta t i n g t he w h o l e t u be. I n t h i s w a y, an y des i r e d t i l t an g l e ca n be ac h i e v e d e ve n i f t h e c o l l e c t o r i s m o u n te d h o r i z o n ta l l y. T h e e f f i c i e n c y o f d i r e c t-f l o w s i n g l e g l ass t u bes is q u i t e h i g h, b u t t he y re q u i r e a g o o d g l ass t o m e ta l sea l t ha t w i t h s ta n ds t he d i f f e re n t hea t e x pa ns i o n r a tes o f t h ose m a te r i a ls.

A ne w t y p e o f c o n ce n t r i c p i p e c o n f i g u r a t i o n i s t he L e n z t u be sh o w n i n F i g u r e 3 1. T h e p i p e f o r t he f l u i d i n l e t i s c o p pe r an d t he o u t l e t p i p e i s g l ass. I n ad d i t i o n t o t he r o ta t i o na l s y m m e t r y, n o c o n ne c t i o n be t w ee n g l ass an d m e ta l i s nee de d t o m a i n t a i n t he v a c u u m. T h e abso r be r i s j a m m e d t o t he o u t l e t p i p e. A g ra p h i te f i l m be t w ee n abso r be r an d o u t l e t p i p e i m p r o v es t he hea t t ra ns f er. C u r r e n t l y t he m o s t c o m m o n t y p e is t he S y d n e y t u be c o l l e c t o r sh o w n i n F i g u r e 6. I t c o ns is ts o f t w o g l ass t u bes f u se d t o ge t her. T h e v a c u u m i s l o ca te d be t w ee n t he t w o t u bes. T h e o u ts i d e o f t h e i n ne r t u be is us ua l l y c oa te d w i t h a sp u t te re d c y l i n d r i c a l se le c t i v e abs o r be r (A l-N/ A l). I n s i d e o f t he i n ne r p i p e, t he hea t i s re m o v e d b y c o p pe r u-t u bes, w h i c h a re e m be d de d i n a c y l i n d r i ca l (alu m i n i u m) hea t t ra ns fe r f i n.

B e ca use t he abs o r be r i s ap p l i e d c o m p l e te l y a r o u n d t he t u be, o f te n a re f l e c t o r i s p l a ce d u n de r t he t u be t o a ls o use t he ra d i a t i o n t ha t passes be t w ee n t he pa ra l l e l m o u n t e d t u bes. T h i s ra d i a t i o n i s re f l e c te d t o t he abso r ber. T h e re i s n o pe r m a ne n t c o n ne c t i o n be t w ee n t he r m o s f l as k t u be an d t he hea t c o n d u c t o r o r t he hea de r o f t he c o l l e c t o r. T h i s m ea ns t ha t t u bes da ma ge d d ue t o e x ce p t i o na l r easo ns ca n eas i l y be re p l a ce d.

2.2.2. Heat pipe evacuated tube collectorsT h e m a i n d i f f e re n ce be t w ee n a hea t p i p e t u be an d a d i r e c t f l o w t u be i s t ha t t h e hea t ca r r i e r f l u i d i n s i de o f t he c o p pe r hea t p i p e i s n o t c o n nec te d t o t he so la r l o o p. I n t h i s case t he re a re t w o d i f f e re n t w a y s o f c o n ne c t i o n. T h e “d r y” c o n ne c t i o n i s sh o w n i n F i g u r e 32. H e r e t he hea t has t o be t ra ns f e r re d f r o m t he c o n de nse r t h r o u g h t he m a te r i a l o f t he hea de r t u be. T h i s w a y t he i n s ta l l a t i o n an d re m o va l o f t h e t u bes is m u c h eas ie r t h a n w i t h d i r e c t f l o w n p i p es b r a ze d t o t he hea der. O n t he o t he r ha n d, hea t-c o n d u c t i v e pas te o f t e n has t o be use d an d t h us re q u i r i n g t ha t t he p i p es be i ns ta l l e d p r o f ess i o na l l y.

I n t he case o f a “ w e t” c o n ne c t i o n, t he f l u i d o f t he so la r l o o p d i r e c t l y f l o w s a r o u n d t he c o n de nse r o f t he hea t p i p es. I n t h i s case, n o hea t-c o n d u c t i v e pas te i s nee de d b u t t he e x c ha n ge o f t u bes is m o r e d i f f i c u l t.

Figure : P rinciple of a heatpipe (Source: Heß and Rommel, in Weiss and Rommel, 2008)

A hea t p i p e i s h o l l o w w i t h l o w p r essu re i ns i d e. T h e o b j e c t i v e i s n o t t o i ns u l a te, b u t ra t he r t o a l te r t he sta te o f t h e l i q u i d i n s i de. I n s i d e t he hea t p i p e i s a s ma l l q ua n t i t y o f p u r i f i e d w a te r an d so me spec ia l ad d i t i v es. W h e n t he hea t p i p e i s hea te d ab o v e an ad j us ta b l e te m pe ra t u re t he w a te r v a p o r i zes. T h i s v a p o u r ra p i d l y r i ses t o t he t o p o f t he hea t p i p e (con de nse r) t ra ns fe r r i n g hea t. A s t he hea t i s t ra ns f e r re d t o t he c o n de nser, t h e v a p o u r c o n de nses t o f o r m a l i q u i d an d re t u r ns t o t he b o t t o m o f t he hea t p i p e t o o n ce aga i n re pea t t he p r o cess. T h e c o n de nse r has a m u c h l a r ge r d i a m e te r t h a n t he sha f t t o p r o v i d e a l a r ge su r f a ce o v e r w h i c h hea t ca n be t ra ns f e r re d t o t he hea der. T o ensu re c i r c u l a t i o n, a hea t p i p e c o l l e c t o r has t o be t i l t e d a t a m i n i m u m an g l e o f o pe ra t i o n (abo u t 20°). T h e q ua l i t y o f t h e hea t t ra nsp o r t a ls o ca n be se r i o us l y a f f e c te d i f t h e hea t p i p e c o n ta i ns t o o m u c h c o n de nsab l e gasses. T h e y ca n f o r m a p o c k e t o f a i r i n t he t o p o f t h e hea t p i p e. T h i s has t he e f f e c t o f m o v i n g t he hea t p i p e’s h o t tes t p o i n t d o w n w a r d a wa y f r o m t he c o n de nser.

F r o s t p r o t e c t i o n i s an issue f o r b o t h t y pes o f c o l l e c t o r. O u t d o o r te m pe ra t u res l o w e r t ha n -1 0 ° C o v e r a l o n g pe r i o d o f t i m e ca n ca use f r ee z i n g. T o a v o i d t h i s, a w a te r/g l y c o l m i x t u r e w i t h an t i-c o r r os i o n ad d i t i v es i s use d i n t he so l a r l o o p f o r f r os t p r o te c t i o n.

T h e hea t p i p e p r i n c i p l e o f f e rs t he t he o r e t i c a l p oss i b i l i t y t o a v o i d sta g na t i o n d ue t o t he res t r i c te d m a x i m u m te m pe ra t u r e t ha t t he hea t p i p e ca n rea c h. D e p e n d i n g o n t he f l u i d an d p r essu re use d t he re i s a te m pe ra t u r e a t w h i c h a l l t h e f l u i d w i t h i n t he hea t p i p e i s v a p o r i ze d an d i n s i de t he c o n de nser. I n t h i s case, t he f l u i d i s l ess e f f e c t i v e i n hea t t ra nsp o r ta t i o n. B e ca use o f t h a t t he te m pe ra t u re o f t h e so la r l o o p sh o u l d be k e p t u n de r t he d i s r u p t i o n te m pe ra t u re o f t h e use d g l y c o l, w h i c h m ea ns w o r k i n g te m pe ra t u res be l o w 1 70 ° C. T h e re l i a b l e ha n d l i n g o f t h i s e f f e c t sens i t i v e l y de pe n ds o n t he r i g h t a m o u n t o f f l u i d an d t he r i g h t p r essu re i n s i de o f t he hea t p i p e. A n o t h e r ap p r oa c h t o a v o i d sta g na t i o n i s t o use a m e m o r y m e ta l t o sepa ra te t he f l u i d i n s i de t he hea t p i p e f r o m t he c o n de nse r i f a ce r ta i n te m pe ra t u r e i s rea c he d.

I n d i r e c t f l o w v a c u u m c o l l e c t o rs t he sta g na t i o n te m pe r a t u re ca n rea c h 300° C so t he g l y c o l an d t he c o m p o n e n ts o f t h e so la r l o o p ha ve t o be p r o te c te d sepa ra te l y.

2.2.3. Current stage of developmentE v a c ua te d t u bes ha ve bee n used f o r y ea rs i n G e r m a n y. I n 2006, t he m a i n m a r k e ts w e re C h i na f o l l o w e d b y G e r m a n y, t he U K , I t a l y an d A u s t ra l i a. B e ca use o f t he i n c r eas i n g q ua n t i t y o f v a c u u m t u bes an d i m p r o v e m e n ts i n t he re f l e c t o r s f o r so la r t he r m a l ap p l i c a t i o n s, v a c u u m c o l l e c t o r s a re be c o m i n g l ess e x pe ns i v e.

C u r r e n t l y v a c u u m t u be c o l l e c t o r s a re a sta n da r d c o m p o ne n t o f so la r t h e r m a l s ys te ms w o r k i n g at h i g he r te m pe ra t u r es. T h e y ca n a ls o be use d i n s tead o f s ta n da r d f l a t-p l a te c o l l e c t o r s t o de c r ease t he ne cessa r y c o l l e c t o r a rea.

2.3. Concentrating flat plate collectorsC o n ce n t ra t i n g f l a t p l a te c o l l e c t o r s use a c o m p o u n d pa ra b o l i c c o n ce n t ra t o r (CPC) t o c o n ce n t ra te so la r ra d i a t i o n o n an abs o r ber. B e c a use t he y a re n o t f o c u ss i n g (non-i m a g i n g), t he y a re a na t u r a l ca n d i d a te t o b r i d ge t he ga p be t w ee n t he l o w e r te m pe r a t u re so la r ap p l i c a t i o n f i e l d o f f l a t-p l a te c o l l e c t o rs (T < 80° C) t o t he m u c h h i g he r te m pe ra t u r e ap p l i ca t i o ns f i e l d o f f o c uss i n g c o n ce n t ra t o rs (T > 200° C). T h e r e a re t w o m a i n d o m a i ns o f ap p l i c a t i o n f o r t he C P C-c o n ce p t:

• L a r ge acce p ta n ce an g l e de v i c es (lo w c o n ce n t ra t i o n); an d

• S m a l l acce p ta n ce an g l e de v i c es (hig h c o n ce n t ra t i o n).

2.3.1. Low concentrationL o w c o n ce n t ra t i o n i s w h a t sh o u l d be use d i f a sta t i o na r y c o l l e c t o r (si m i l a r t o a f l a t-p l a te c o l l e c t o r) is t o be de v e l o pe d. T h e c o l l e c t o r sh o w n i n F i g u r e 33 is a spec i f i c case w h e r e t he abs o r be r i s n o l o n ge r f l a t, b u t has a t r i a n g u l a r shape. W i t h i ts l o w v a l u e o f c o n ce n t ra t i o n an d t he use o f a se le c t i v e abs o r ber, t he c o l l e c t o r sh o w n i n F i g u r e 33 be ha v es l i k e a v e r y g o o d f l a t-p l a te c o l l e c t o r an d ac h ie ves h i g h pe r f o r m a n ce.

I f t he c o n ce n t ra t i o n f a c t o r i s i n c r eased an d o t he r m ea ns t o c o n t r o l hea t l o sses a re ad de d, t he res u l t i n g c o l l e c t o r s ha v e a d i s t i n c t l o w e r hea t l oss f a c t o r, ap p r oa c h i n g t ha t o f e va c ua te d t u be c o l l e c t o r s. F i g u re 34(a) sh o w s a c o l l e c t o r w i t h a h i g he r c o n ce n t ra t i o n f a c t o r. C o n v e c t i o n l osses o f t h e c o l l e c t o r ca n be re d u ce d, f o r e xa m p l e, b y us i n g t ra nspa re n t i ns u l a t i o n m a te r i a ls (TI M) as sh o w n i n F i g u r e 34(b). T h i s t y p e o f c o l l e c t o r i s e x pec te d t o pe r f o r m v e r y w e l l i n p r o m i s i n g so la r ap p l i ca t i o ns, suc h as abso r p t i o n c o o l i n g, desa l i n a t i o n an d i n d u s t r i a l p r o cesses, be ca use i t ca n de l i v e r hea t a r o u n d an d ab o v e 1 00 ° C. N o n-e va c ua te d C P C c o l l e c t o r s ca n be m a n u f a c t u r e d a t t he c os t o f g o o d c o n v e n t i o na l f l a t-p l a te c o l l e c t o r s, ca n be m o u n te d an d use d l i k e f l a t-p l a te c o l l e c t o r s, an d de m o ns t ra te t he sa me h i g h l e ve l o f d u r a b i l i t y. A n o t he r c o n f i g u r a t i o n i s t o use e vac ua te d t u bes w i t h C P C c o l l e c t o r s (see F i g u r e 35), w h i c h i n c reases e f f i c i e n c i es.

Figure : Cross section of a non-evacuated C PC collector

Figure : (a): Cross section of a C PC, (b): Collector of (a) with T I M

Figure : Collector that combines evacuated tubes with C PCs (Source: Solarfocus reproduced by EST IF, 2006)

2.3.2. H igh concentrationC P C c o l l e c t o r s, e ve n w i t h m o d es t c o n ce n t ra t i o n ra t i o s, c o u l d be v e r y ta l l an d t he re f o r e t o ta l l y i m p r a c t i c a l. B y c o m p a r i s o n, f o c uss i n g c o n ce n t ra t o r s a re q u i te c o m pa c t, w h i c h use sec o n d-sta ge c o n ce n t ra t o r s t ha t a re o f t he i d ea l N o n-I m a g i n g O p t i cs t y pe. S o me c o l l e c t o r s o n t he m a r k e t t o da y use t h i s c o n ce p t, w h e r e a sec o n d-stage C P C t y pe c o n ce n t ra t o r f u r t h e r c o n ce n t ra tes t he ra d i a t i o n e me r g i n g f r o m a l i n ea r p r i m a r y c o n ce n t ra t o r o f t he F r esne l t y p e.

2.4. Concentrating collectors with trackingC o n ce n t ra t i n g c o l l e c t o r s w i t h t ra c k i n g a re s i m i l a r t o t he C SP s ys te ms as desc r i b e d i n sec t i o n 2. 1.2. F o r suc h ap p l i c a t i o ns, t he p o w e r c y c l e (fo r e le c t r i c i t y ge ne ra t i o n) is re p l a ce d w i t h a d i r e c t ap p l i ca t i o n o f t h e c o l l e c te d hea t; su c h (poten t i a l) ap p l i c a t i o n s a re c o n t i n u o us l y resea r c he d.

2.4.1. S m all parabolic trough collectorsS ma l l e r pa ra b o l i c t r o u g hs ca n o pe ra te at te m pe ra t u res be t w ee n 1 00 ° C an d 250° C. T h e ape r t u r e w i d t h o f t hese s ma l l t r o u g hs r a n ges f r o m 50 c m t o 2.3 m . T h e ad va n ta ge o f t h ese s ma l l t r o u g hs is t ha t t he y a re re la t i v e l y l i g h t w e i g h t an d eas ie r t o ha n d l e. S o me o f t he m ca n e ve n be i ns ta l l e d o n r o o f s.

D u e t o t he c o n ce n t ra t i n g na t u re o f pa ra b o l i c t r o u g h c o l l e c t o r s, t he y a re bes t ap p l i e d i n c l i m a tes t ha t ha ve a h i g h sha re o f d i r e c t so la r r a d ia t i o n. H o w e v e r i n m o de ra te c l i m a tes, su c h as i n C e n t r a l E u r o pe, pa ra b o l i c t r o u g h c o l l e c t o r s ha v e t he sa me ad va n ta ge o v e r f l a t-p l a te o r e va c ua te d t u be c o l l e c t o r s as i n su n n i e r c l i m a tes i f o pe ra t i n g te m pe ra t u r es a re r o u g h l y ab o v e 1 30 ° C. A t l o w e r te m pe r a t u res an d be ca use t he y ca n n o t use t he d i f f u se so la r ra d i a t i o n, t he o v e ra l l so la r ene r g y y i e l d i s st i l l s ma l l e r t h a n t ha t o f an e vac ua te d t u be c o l l e c t o r. A s a l w a ys, ca re f u l s ys te m des i g n t ha t ta kes i n t o acc o u n t t h e c o r re c t o pe ra t i n g te m pe ra t u r es, l o a d c ha ra c te r i s t i cs an d re l i a b l e c l i m a t e da ta i s i m p o r t a n t.

Pa ra b o l i c t r o u g hs ca n be o pe ra te d i n a p ressu r i se d c i r c u i t w h e r e t he hea t t ra ns fe r m e d i u m d oes n o t e va p o r a te i n t he c o l l e c t o r f i e l d (ind i r e c t m o de). T h e y a ls o ca n be o pe ra te d i n a d i re c t s tea m ge ne ra t i n g m o de. I n t he i n d i r e c t m o de, t y p i c a l hea t t ra ns fe r m e d i a a re t he r m a l o i l o r w a te r. I n t he d i r e c t s tea m ge ne ra t i o n m o de, w a te r i s t he bes t so l u t i o n i n re g i o n s w h e r e t he re i s n o da n ge r o f f r ee z i n g. A l t e r n a t i v e hea t t ra ns fe r m e d i a t ha t p r o v i d e f r ee ze p r o t e c t i o n a re c u r re n t l y u n de r i n v es t i g a t i o n.

P oss i b l e f i e l ds o f ap p l i ca t i o n o f s ma l l pa ra b o l i c t r o u g h c o l l e c t o r s a re:

• I n d u s t r i a l p r o cesses w h e r e hea t a t a te m pe ra t u r e h i g he r t ha n ap p r o x i m a te l y 1 00 ° C t o 1 30 ° C (depe n d i n g o n c l i m a t e c o n d i t i o n s) is nee de d. T h e y ca n be use d t o ge ne ra te stea m e i t he r i n d i re c t s tea m ge ne ra t i o n m o de o r us i n g an i n d i r e c t l y f i r e d stea m ge ne ra t o r. T h e stea m ca n be f e d i n t o stea m hea t d i s t r i b u t i o n ne t w o r k s t ha t a re used w i d e l y i n i n d us t r y.

• D r i v i n g abs o r p t i o n c h i l l e rs, w h e t he r s i n g l e o r t he m o s t p r o m i s i n g, d o u b l e-sta ge m a c h i n es. T h ese l as t m e n t i o ne d c h i l l e rs ha v e a h i g he r e f f i c i e n c y t ha n s i n g l e-sta ge abs o r p t i o n c h i l l e rs an d d ue t o t he i r l o w e r o pe ra t i n g te m pe r a t u re a re used f o r m o s t so la r c o o l i n g ap p l i ca t i o ns.

I n o r de r t o en la r ge t he so la r t h e r m a l m a r k e t t o t he te m pe r a t u re ra n ge t ha t i s c ha ra c te r i s t i c f o r s ma l l pa ra b o l i c t r o u g hs, se ve ra l s ma l l-sca le pa ra b o l i c t r o u g h des i g ns a re c u r re n t l y u n de r de ve l o p me n t. O n e c o l l e c t o r f r o m t he G e r m a n c o m p a n y S O L I T E M i s n o w o n t he m a r k e t. F o r a l l o t h e r s ma l l pa ra b o l i c t r o u g h c o l l e c t o rs t he f i r s t tes t resu l ts o f p r o t o t y p e c o l l e c t o r s a re a va i l a b le, b u t t h e y a re n o t y e t r ead y t o en te r t h e m a r k e t.

2.4.2. L inear Fresnel collectorsW h e n sca le d d o w n, t he l i n ea r F r es ne l c o l l e c t o r m ee ts t he spec i a l b o u n da r y c o n d i t i o n s f o r t h e ge ne ra t i o n o f i n d us t r i a l p r o cess hea t:

• T h e c o l l e c t o r ca n be used f o r p r o cesses sta r t i n g w i t h a t he r m a l ca pa c i t y o f a r o u n d 50 k W and u p t o se ve ra l M W .

• T h e c o l l e c t o r i s eas y t o m o u n t o n f l a t r o o f s as a resu l t o f g o o d w e i g h t d i s t r i b u t i o n an d l o w w i n d res is ta n ce. I t a ls o a l l o w s v e r y h i g h su r f a ce c o v e ra ge so t ha t t h e hea t ca n be p r o d u ce d c l ose t o w h e r e i t i s nee de d an d t o w h e r e space is n o t so f r ee l y a va i l a b l e.

Se v e ra l i n d u s t r i a l g r o u ps a re c o m m e r c i a l l y o f f e r i n g l i n ea r c o n ce n t ra t i n g F r esne l c o l l e c t o r s an d a re de v e l o p i n g p r o j e c ts f o r so l a r t he r m a l p o w e r ge ne ra t i o n. T h e G e r m a n c o m p a n y PS E A G o f f e rs a l i n ea r c o n ce n t ra t i n g F r es ne l c o l l e c t o r f o r i n d us t r i a l p r o cess hea t ap p l i ca t i o ns, w h i c h i s i d ea l l y su i te d f o r r o o f t o p i ns ta l l a t i o ns. A t t h i s t i m e, t h r ee s ys te ms ha ve bee n i ns ta l l e d. A p r o t o t y p e i n F r e i b u r g, G e r m a n y t ha t i s be i n g use d f o r de ta i l e d pe r f o r m a n ce m eas u r e me n ts. A sec o n d s ys te m i n B e r ga m o, I t a l y i s p o w e r i n g a N H 3/H2O abs o r p t i o n c h i l l e r (see F i g u r e 36). I n t he l a tes t i ns ta l l a t i o n, a 1 7 6 k W p (352 m ²) c o l l e c t o r w a s i ns ta l l e d o n a r o o f a t t h e U n i v e rs i t y o f Se v i l l e t o p o w e r a d o u b l e e f f e c t H 2O/ L i B r c h i l l e r. F u r t h e r p r o j e c ts a re c u r r e n t l y be i n g de ve l o pe d.

Figure : L inear concentrating F resnel collector in Berga mo, Italy–a demonstration system for solar cooling

(Source: Weiss and Rommel, 2008)

2.4.3. Solar thermochemistrySo l a r t h e r m o c he m i c a l p r o cesses c o n v e r t r a d ia n t ene r g y i n t o c he m i ca l ene r g y, w i t h t he abs o r be d, c o n ce n t ra te d, so la r ra d i a t i o n d r i v i n g an en d o t he r m i c c he m i ca l rea c t i o n (W W G an d M M A , 2008). C o n ce n t ra te d so la r ra d ia t i o n i s used as t he ene r g y so u r ce f o r h i g h te m pe r a t u re p r o cess hea t t o d r i v e c he m i ca l r ea c t i o ns t o w a r ds t he p r o d u c t i o n o f s t o ra b l e an d t ra ns p o r ta b le f u e l s (see F i g u r e 37 - A). T h e “so la r f u e l s” c o m m u n i t y n o w c o n ce n t ra tes l a r g e l y o n: c rea t i n g e i t he r h y d r o ge n o r s y n gas b y e x p os i n g w a te r v a p o u r an d f o ss i l f u e l s t o c o n ce n t ra te d so la r ra d i a t i o n i n t he p r esen ce o f a ca ta l y s t (the f i r s t ap p r oa c h); o r sp l i t t i n g t he w a te r m o l e c u l e i n t o i ts c o ns t i t ue n t o x y g e n an d h y d r o ge n f o r use i n f u e l ce l l s o r o t he r ap p l i c a t i o n s (the sec o n d ap p r oa c h). T h e c lass i c “c he m i ca l hea t p i p e” (see F i g u re 37 – B) ap p r oa c h is n o l o n ge r f o l l o w e d. I n b o t h cases t he so la r h y d r o ge n ec o n o m y i s t he d r i v e r be h i n d t he r esea r c h; t he resea r c h p r o g r a m m e is desc r i b e d i n F i g u r e 38.

Figure : H igh temperature solar thermochemical concepts (Source: Steinfeld and Palumbo, 2001)

T h e c o n ce p t i s t o m o v e f r o m c u r re n t c hea p ca r b o n-r i c h p r o cesses (stea m re f o r m i n g o f m e t ha ne us i n g c o m b us t i o n, gas i f i ca t i o n o f c oa l b y c o m b us t i o n), t h r o u g h ca r b o n-l ea n p r o cesses (so la r s tea m re f o r m i n g o f m e t ha ne, so l a r gas i f i c a t i o n an d re f o r m i n g o f Pe t c o k e) an d ca r b o n-ne u t ra l p r o cesses (so la r p y r o l y s i s o f b i o m ass), t o u l t i m a t e l y e x pe ns i v e b u t ca r b o n-f r ee an d re ne w a b l e sp l i t t i n g o f w a te r (stea m e le c t r o l y s i s, t h e r m o c h e m i ca l w a te r sp l i t t i n g us i n g re ve rs i b l e m e ta l o x i d e, su l p h u r-based o r o t he r r ea c t i o n s). F u e l i s c u r re n t l y e x c l us i v e l y f o ss i l-based, w i t h C O 2c rea te d d u r i n g re f i n i n g o r d u r i n g F i s c he r-T r o ps c h s y n t hes is an d d u r i n g c o m b us t i o n. I n t he f u t u r e i t i s h o pe d f u e l ca n be c o m p l e te l y re ne w a b l e-base d w i t h n o C O 2f o o t p r i n t a t a l l.

Figure : Solar thermal processes for hydrogen production (Source: Sattler, 2007)

T h e s i m p l es t an d c hea pes t ca r b o n-l ea n step o n t h i s pa t h w a y is t he so la r s tea m re f o r m i n g o f m e t ha ne:

C H 4+ H 2O + hea t C O + 3 H→ 2

C O + H 2O + hea t C O→ 2+ H 2

I n t h e p r o cess f o u r H 2 m o l e c u l es w e re re leased w i t h t he c o ns u m p t i o n o f eac h C H 4 m o l e c u l e, an d a s i n g l e C O 2 m o l e c u l e w a s re leased. I n t he a l te r na t i v e c o m b us t i o n-based p r o cess, t he f o l l o w i n g o c c u rs:

C H 4+ 2 O 2 C O→ 2+ 2 H 2O + hea tC H 4+ H 2O + hea t C O + 3 H→ 2

C O + H 2O + hea t C O→ 2+ H 2

F r o m a m ass c o m pa r a t i v e pe rs pe c t i v e, t o p r o d u ce 1 k g o f H 2 b y re g u l a r s tea m m e t ha ne re f o r m i n g, 9.42 k g o f C O 2 i s p r o d u ce d, w h i l e f o r so la r s tea m re f o r m i n g o f m e t ha ne o n l y 5.5 k g o f C O 2 i s p r o d u ce d (Sat t l e r, 2007). T h e so la r stea m re f o r m i n g o f m e t ha ne ra i ses t he ca l o r i f i c v a l u e o f t he o r i g i n a l m e t ha ne b y 26 %, st o r i n g t he so la r hea t c he m i ca l l y. S o l a r stea m m e t ha ne re f o r m i n g has bee n i n v es t i g a te d b y e ve r y m a j o r so la r resea r c h i ns t i t u t i o n: t he W e i z m a n n I n s t i t u te o f S c ie n ce i n I s rae l, t h e D L R i n G e r m a n y, t he Pau l S c he r re r I n s t i t u te i n S w i t ze r l a n d, t he C S I R O i n A u s t r a l i a as w e l l as Japa nese resea r c he rs. T h e m e t ha ne-based p r o cess, w h i c h has u n de r g o ne c o ns i de ra b le de v e l o p m e n t i n A u s t r a l i a, i s an e xa m p l e o f a h y b r i d so la r/f oss i l p r o cess (W W G and M M A , 2008). T h e p r o d u c ts (in t h i s case s y n gas) a re f u e l s w h o se q ua l i t y has bee n u p g r a de d b y so la r ene r g y. T h a t i s, t he ca l o r i f i c v a l u e i s i n c r eased ab o v e t ha t o f t he f o ss i l f u e l b y so la r ene r g y i n p u t eq ua l t o t he en t ha l p y c ha n ge o f t h e rea c t i o n. I n c reased ene r g y c o n t e n t m ea ns e x te n de d f u e l l i f e an d re d u ce d p o l l u t i o n o f t he en v i r o n me n t. T h e re f o r e, t hese f ue l s a re c o ns i d e re d t o be c l ea ne r f u e l s. T h e m i x o f so la r an d f o ss i l ene r g i es c r ea tes a l i n k be t w ee n c u r r e n t f o ss i l f u e l-based te c h n o l o g i es an d f u t u re so la r c he m i ca l te c h n o l o g i es (see F i g u r e 39), i n c l u d i n g t he p r o d u c t i o n o f h y d r o ge n (W W G and M M A , 2008).

Figure : A ustralian C S I R O’s envisaged supply chain for its SolarGasT M technology (Source: det.csiro.au)

U n f o r t u na te l y, S o u t h A f r i c a d oes n o t ha v e s i g n i f i c a n t rese r ves o f m e t ha ne, b u t i t d oes ha ve an ab u n da n ce o f c oa l. I n t he c o n v e n t i o na l K o p p e rs-T o t ze k/Te xac o p r o cess, w i t h s i m i l a r c he m i ca l rea c t i o ns as desc r i b e d ab o v e, 23 k g o f C O 2 i s p r o d u ce d f o r e ve r y 1 k g o f H 2, w h i l e t he so la r gas i f i c a t i o n o f c oa l su g ges ts o n l y 1 1 k g o f C O 2 i s p r o d u ce d pe r k g o f H 2(Sat t l e r, 2007). F r o m t h i s i t ca n be seen t ha t t he i n t r o d u c t i o n o f so la r p r o cesses r e d u ces C O 2e m i ss i o ns b y ha l f f o r b o t h c oa l an d m e t ha ne, an d c o ns u mes ab o u t ha l f t he f ee ds t o c k, f o r t h e sa me y i e l d o f H 2. T h e C S I R is c u r r e n t l y i n v es t i g a t i n g b o t h so la r stea m m e t ha ne re f o r m i n g an d so la r gas i f i c a t i o n o f c oa l.

T h e ca r b o n-f r ee p r o d u c t i o n o f H 2ca n is d o ne i n a n u m be r o f w a y s:

• R e ne w a b l y ge ne ra te d e le c t r i c i t y ca n be used t o e le c t r o l y se w a te r (an e x pe ns i v e ap p r oa c h).

• S tea m a t 800 C ca n be e le c t r o l y se d (usi n g re ne w a b l e e le c t r i c i t y) at t w o-t h i r ds t he e le c t r i c i t y˚ c o ns u m p t i o n i n a so l i d o x i d e f ue l ce l l r u n n i n g i n r e ve rse.

• A m e ta l o x i d e ca n be re d u ce d us i n g c o n ce n t ra te d so la r ra d i a t i o n, an d t he re d u ce d m e ta l (or o x i d e, i n t he case o f f e r r o u s o x i d es) e x p osed t o w a te r v a p o u r. T h e m e ta l o r o x i d e re-o x i d i ses, re leas i n g H 2 i n a ba t c h-w i se p r o cess.

• Se ve ra l su l p h u r-based p r o cesses e x i s t; W es t i n g h o use o r h y b r i d su l p h u r, an d t he S I p r o cess a re t w o e xa m p l es.

T h e D S T-esta b l i s h e d h y d r o ge n h u bs m a y w e l l be d r i v e rs t o de ve l o p t hese t y p es o f p r o cesses i n S o u t h A f r i c a. W h i l e n o t s t r i c t l y t h e r m o c h e m i s t r y, t he so la r s me l t i n g o f sec o n da r y a l u m i n i u m is an o t he r i d ea l ap p l i c a t i o n f o r a c o n ce n t ra t i n g so la r t he r m o c he m i s t r y f a c i l i t y. A c c o r d i n g t o R oe b et a l (200 1), 5 % o f t he e le c t r i c i t y ge ne ra te d i n t he w o r l d i s c o ns u me d i n t he p r o d u c t i o n o f p r i m a r y a l u m i n i u m f r o m ba u x i te. T h e s me l t i n g o f sec o n da r y (or sc ra p) a l u m i n i u m c o ns u mes 1 0 % o f t he ene r g y, an d re leases 1 0 % o f t he e m i ss i o ns, c o m p a r e d t o p r i m a r y a l u m i n i u m. I n W es te r n E u r o pe an d U S A , sec o n da r y a l u m i n i u m p r o d u c t i o n i s ab o u t t w o-t h i r ds t ha t o f p r i m a r y p r o d u c t i o n. Japa n has n o ap p r e c ia b l e p r i m a r y a l u m i n i u m p r o d u c t i o n, o n l y sec o n da r y p r o d u c t i o n. S o u t h A f r i c a, b y c o n t ras t, has o n l y p r i m a r y a l u m i n i u m p r o d u c t i o n; t he sc ra p a l u m i n i u m is e x p o r te d, l a r g e l y t o Japa n.

T h e use o f c o n ce n t ra t i n g so la r i s a g o o d f i t t o s me l t i n g sec o n da r y a l u m i n i u m, as:

• T h e m e l t i n g o f sc ra p is a ba t c h w i se p r o cess, l i k e t he so la r reso u r ce;

• A l u m i n i u m m e l t s a t 660 C, i d ea l f o r so l a r p r o cesses; an d˚• D i f f e r e n t g r a des o f sc ra p a l u m i n i u m (e.g. ae r os pace g r a de 7075) ca n be s me l te d sepa ra te l y.

R o e b et a l. (200 1) p r o d u ce d a r o ta r y k i l n f o r t he s me l t i n g o f sec o n da r y a l u m i n i u m, an d tes te d i t i n t he D L R so la r f u r n a ce i n C o l o g ne.

3. International market trends and drivers, and cost implications

T h e p r o j e c t i o n s a re t ha t so la r ene r g y te c h n o l o g i es w i l l , o v e ra l l, p l a y a s i g n i f i ca n t r o l e i n t he f u t u r e ene r g y su p p l y an d de ma n d l a n dsca pe (RE N 2 1, 2009), espec ia l l y be y o n d 2040 (see F i g u r e 40). T h e c o n t r i b u t i o n o f so l a r t he r m a l ap p l i ca t i o ns m a y re ma i n re l a t i v e l y s ma l l, b u t i t i s e x pe c te d t ha t so la r p o w e r ap p l i ca t i o ns w i l l , e ve n t u a l l y, o v e r ta ke t he c o m b i n e d c o n t r i b u t i o n s o f a l l o t h e r ene r g y r es o u r ces.

Figure : P rojected global primary energy consumption (Source: Weber, 2009)

4. Power applications

4.1. P V systems – trendsT h e so la r P V i n d us t r y c o n t i n ues t o be o ne o f t he f as tes t g r o w i n g i n d u s t r i es. G l o b a l an n ua l p r o d u c t i o n i n c reased nea r l y s i x-f o l d be t w ee n 2004 an d 2008, r ea c h i n g 6.9 G W (RE N2 1, 2009), w i t h ne w l y i ns ta l l e d ca pac i t y, f o r 2008, r ea c h i n g nea r l y 5.5 G W (see F i g u r e 4 1 an d Ta b l e 1 0). A n n u a l p r o d u c t i o n i n 2008 w a s 90 pe r ce n t h i g he r t ha n i n 2007. C h i n a su r passed Japa n t o be c o me t he ne w w o r l d l ea de r i n P V ce l l p r o d u c t i o n (1.8 G W n o t c o u n t i n g Ta i w a n), w i t h G e r m a n y m o v i n g u p t o sec o n d p l a ce (1.3 G W), f o l l o w e d b y Japa n (1.2 G W), Ta i w a n (0.9 G W), an d t he U n i t e d S ta tes (0.4 G W). A l t h o u g h t he U n i t e d S ta tes r a n k e d f i f t h o v e ra l l, i t l e d t he w o r l d i n t h i n-f i l m p r o d u c t i o n (270 M W), f o l l o w e d b y M a l a y s i a (240 M W) and G e r ma n y (220 M W). G l o b a l t h i n-f i l m p r o d u c t i o n i n c r eased 1 20 pe r ce n t i n 2008, t o rea c h 950 M W . N e v e r t h e l ess, s i n g l e c r y s ta l l i n e an d p o l y c r y s ta l l i n e m o d u l es d o m i n a te t he m a r k e t (see F i g u r e 42).

Figure : Global P V-installations (Source: Weber, 2009)

Table : Grid-connected solar P V, 2004 to 2008 ( megawatts) 5

(Source: R E N21, 2009)

Country 2004 2005 2006 2007 2008

Added Added Existing Added Existing Added Existing Added Existing

G e r m a n y 600 860 1 900 900 2800 1 1 00 3900 1 500 5400

S pa i n 1 2 23 50 1 00 1 50 550 700 2600 3300

Japan 270 3 10 1 200 290 1 490 240 1 730 240 1 970

C a l i f o r n i a 47 55 220 70 320 95 480 1 50 730

O t h e r U S A 1 0 1 0 - 30 - 65 - 1 00 -

O t h e r E U 1 0 40 1 30 50 1 80 1 70 350 400 750

S o u t h K o r ea 3 5 1 5 20 35 60 1 00 250 350

O t h e r w o r l d - >20 >30 >50 >80 > 150 >250 >200 >450

C u m u l a t i v e - - 3500 - 5 100 - 7500 - 1 2950

Figure : Development of the global P V-market till 2007(Source: Weber, 2009)

T h e re w e r e m a j o r c ha n ges i n c o m p a n y sha res d u r i n g 2007/2008. Q-C e l l s o f G e r m a n y beca me t he l ea d i n g so la r P V p r o d u ce r w o r l d w i d e i n 2007 an d m a i n t a i ne d t ha t l ea d w i t h 570 M W o f ce l l s p r o d u ce d i n 2008. F i r s t S o l a r d o u b l e d p r o d u c t i o n i n 2008, t o 500 M W , w i t h e x pa n de d m a n u f a c t u r i n g i n G e r m a n y an d ne w m a n u f a c t u r i n g i n

5

5

A l l f i g u r es a re ap p r o x i m a t e an d su b j e c t t o re v i s i o n w i t h f u t u r e d a ta. T h ese f i g u r es d o n o t i n c l u d e es t i m a tes f o r t he a m o u n t o f o f f-g r i d P V i ns ta l l e d an n ua l l y. T h e r e i s a w i d e d i s pa r i t y i n es t i m a tes f o r ad de d P V i n se ve ra l c o u n t r i es f o r t he y ea rs 2006 t o 2008 i n pa r t i c u l ar. P V N e w s (Pro m e t he us I n s t i t u t e) has bee n t he m a i n so u r c e o f P V i ns t a l l a t i o n da ta s i n ce t he o r i g i n a l R e ne w a b l es 2005 G l o b a l S ta t us R e p o r t, b u t da ta f r o m o t he r so u r c es ha ve a ls o bee n c o ns i de re d an d i n c o r p o ra te d. F i g u r es f o r G e r m a n y e x h i b i t e d w i d e d i s pa r i t y f o r 2006 and 2007, b u t es t i m a tes f r o m d i f f e r e n t so u r c es see m t o ha v e c o n v e r ge d f o r 2008. S ys tè mes S o l a i r es g i v es 1 1 00 M W f o r G e r m a n y i n 2007, w h i l e o t he r es t i m a tes g i v e 1 200 t o 1 260 M W . E s t i m a tes f o r S o u t h K o r ea i n 2008 ra n ge f r o m 95 M W t o 270 M W . E s t i m a tes f o r I t a l y i n 2008 ra n ge f r o m 1 75 M W t o 340 M W . S ys tè mes S o l a i r es g i v es 200 M W ad ded i n I t a l y i n 2008. E x p e r t es t i m a tes p u t t o t a l g r i d-t i e d P V i ns t a l l a t i o ns i n 2008 at b e t w ee n 4.5 G W and 5.6 G W, w i t h o n e est i m a te o f o f f-g r i d P V at 0.3 G W. A sma l l pa r t o f t he d i s pa r i t i es a r i se f r o m t ra c k i n g o f f-g r i d v e rs us o n-g r i d i ns t a l l a t i o ns, as p u b l i s he d g l o ba l f i g u r es d o n o t d i s t i n g u i s h be t w ee n t hese t w o, e x ce p t f o r S ys t è mes S o l a i r es f o r t he E U. T h e d i s pa r i t y i n es t i m a tes f o r t o t a l i ns t a l l e d ca pac i t y a ls o i n c l u d es d i f f e re n ces i n h o w e x pe r ts ac c o u n t f o r p r o d u ce d b u t u n i ns t a l l e d ca pa c i t y, i n c l u d i n g p r o j e c t p i pe l i n es an d e x cess i n v e n t o r y. I n 2008 t he re w as an est i m a te d 1 G W o r m o r e o f e x cess i n v e n t o r y t ha t w a s n o t i ns t a l l e d, as p r o d u c t i o n f a r o u ts t r i p pe d i ns ta l l a t i o n, an d d i f f e re n t m e t h o ds o f es t i m a t i n g t h i s m o r e p re c ise l y y i e l d d i f f e r e n t t o t a ls. T h i s i s a ls o t he reaso n t ha t es t i m a tes f o r 2008 m a y be r e v i se d i n f u t u r e y ea rs. S ys t è mes S o l a i r es g i v es 5350 M W c u m u l a t i v e f o r G e r m a n y and 3400 M W c u m u l a t i v e f o r S pa i n i n 2008, an d E U c u m u l a t i v e o f 9500 M W .

M a l a y s i a. S u n te c h o f C h i n a t r i p l e d ce l l p r o d u c t i o n f r o m 1 60 M W i n 2006 t o 500 M W i n 2008, t o t i e f o r sec o n d p l a ce w i t h F i r s t S o l a r. B y t he en d o f 2008, S u n te c h c l a i m e d t o ha ve rea c he d 1 G W p r o d u c t i o n ca pac i t y i n b o t h m o d u l es an d ce l l s, t he h i g hes t ce l l ca pa c i t y o f an y P V c o m p a n y. F o r m e r w o r l d l ea de r S ha r p o f Japa n f e l l t o f o u r t h p l a ce, w i t h 470 M W o f ce l l s p r o d u ce d i n 2008.

T h e g l o ba l P V i n d us t r y en de d 2008 w i t h o v e r 8 G W o f ce l l m a n u f a c t u r i n g ca pac i t y, i n c l u d i n g 1 G W o f t h i n-f i l m ca pac i t y. A n d d u r i n g t he y ea r, t h e so la r P V i n d us t r y an n o u n ce d ad d i t i o na l m a j o r p r o d u c t i o n ca pac i t y e x pa ns i o ns, m a n y o f t h e m f o r t h i n-f i l m te c h n o l o g y. F o r e xa m p l e, M a s d a r P V an n o u n ce d $2 b i l l i o n o f i n v es t m e n ts t o ad d 2 10 M W o f t h i n-f i l m p r o d u c t i o n ca pac i t y. A n d t he re w e r e o v e r 200 c o m p a n i es p r o d u c i n g t h i n-f i l m m o d u l es o r p l a n n i n g t o d o so. H o w e v e r, m a n y o f t h ese p l a ns w e re i n q ues t i o n a f te r t h e 2008 m a r k e t c rash, an d so me ca n ce l l a t i o n s w e re su bseq ue n t l y an n o u n ce d. F o r e xa m p l e, S u n te c h ca n ce l l e d p l a ns t o i n c rease p r o d u c t i o n ca pac i t y (not j us t t h i n-f i l m) b y 0.4 G W d u r i n g 2009. B P an d S he l l ha v e a ls o an n o u n ce d p l a n t c l os u res (RE N 2 1, 2009).

I n d i a e me r ge d i n 2008 as an asp i r i n g p r o d u ce r o f so la r P V. B o t h na t i o na l an d sta te g o v e r n m e n ts an n o u n ce d ne w p o l i c i es t o su p p o r t so l a r P V m a n u f a c t u r i n g i n spec i a l ec o n o m i c z o nes, i n c l u d i n g ca p i ta l i n v es t me n t su bs i d i es o f 20 pe r ce n t. T h ese p o l i c i es l e d t o $ 1 8 b i l l i o n i n ne w so la r P V m a n u f a c t u r i n g i n v es t m e n t p l a ns o r p r o p osa ls b y a n u m be r o f c o m p a n i es (RE N 2 1, 2009).

O v e r a l l t he so la r P V m a r k e ts sh o w e d t h ree c l ea r t re n ds i n 2008. T h e f i r s t w a s t he g r o w i n g at te n t i o n t o b u i l d i n g-i n te g ra te d P V (BIP V), w h i c h i s a s ma l l b u t f as t-g r o w i n g seg me n t o f so me m a r k e ts, w i t h m o r e t ha n 25 M W i ns ta l l e d i n E u r o p e. Se c o n d, t h i n-f i l m so la r P V te c h n o l o g i es be ca me a l a r ge r sha re o f t o ta l i ns ta l l a t i o n s. A n d t h i r d, u t i l i t y-sca le so la r P V p o w e r p l a n ts (de f i ne d as l a r ge r t h a n 200 k W) e me r ge d i n l a r g e n u m b e rs i n 2008. B y t he en d o f 2008, an est i m a te d 1 800 suc h p l a n ts e x i s te d w o r l d w i d e, u p f r o m 1 000 at t he en d o f 2007. A l t o g e t h er, t hese p l a n ts t o ta l l e d o v e r 3 G W, a t r i p l i n g o f e x i s t i n g ca pac i t y f r o m 2007 (RE N 2 1, 2009).

4.2. P V systems – driversA k e y d r i v e r f o r t he p r o m o t i o n o f p h o t o v o l t a i c s ys te ms has bee n t he c ha n ge i n t he p o l i c y l a n dsca pe (see sec t i o n 3.3), an d spec i f i c a l l y t h e i n t r o d u c t i o n o f f ee d-i n ta r i f f sche mes (see F i g u r e 43). D i r e c t P V ene r g y c o n v e rs i o n i s based o n se m i c o n d u c t o r te c h n o l o g y, t he p r i ce o f w h i c h i s e x pe c te d t o f o l l o w a steep l ea r n i n g c u r v e (see F i g u r e 44), so t ha t t he te c h n o l o g i c a l s ys te ms w i l l be c o me c o m pe t i t i v e w i t h e le c t r i c i t y f r o m f o ss i l an d n u c l ea r so u r ces w i t h i n t he ne x t t w o t o t h ree de ca des (see F i g u r e 45); an o t he r d r i v e r f o r P V s ys te ms.

Figure : P hotovoltaic world m arket (2008) (Source: Weber, 2009)

Figure : P r ice learning curve of crystalline S i P V-modules (Source: Weber, 2009)

Figure : Cost trends for U S electricity generation (2006 – 2030) (Source: Cowan and Daim, 2009)

4.3. CS P systems – trendsT w o ne w c o n ce n t ra t i n g so la r (ther m a l) p o w e r (CSP) p l a n ts ca me o n l i n e i n 2008: t he 50 M W A n d as o l- 1 pa ra b o l i c t r o u g h p l a n t i n S pa i n, an d a 5 M W cen t ra l re ce i v e r de m o ns t ra t i o n p l a n t i n C a l i f o r n i a. T h ese f o l l o w e d o n t h r ee ne w pa ra b o l i c t r o u g h p l a n ts d u r i n g 2006/2007; t he f i r s t i n o ne an d a ha l f de ca des (see F i g u re 46). A n u m be r o f ad d i t i o na l p r o j e c ts t ha t ha v e bee n d ue t o c o m e o n l i n e i n 2009, i n c l u de t w o m o r e 50 M W p l a n ts an d

20 M W o f C SP i n te g r a te d w i t h a 450 M W na t u ra l-gas c o m b i ne d-c y c l e p l a n t i n M o r o c c o; t h i s w o u l d be t he f i r s t o pe ra t i o na l p l a n t o f t h i s t y pe. T h e p i p e l i n e o f p r o j e c ts u n de r de v e l o p m e n t o r c o ns t r u c t i o n i n c r eased d ra ma t i ca l l y d u r i n g 2008, t o m o r e t ha n 8 G W b y so me est i m a tes, w i t h o v e r 6 G W u n de r de v e l o p m e n t i n t he U n i t e d S ta tes a l o ne. N e w p r o j e c ts a re u n de r c o n t r a c t i n A r i z o na, C a l i f o r n i a, F l o r i d a, N e v a da, an d N e w M e x i c o i n t he U n i t e d S ta tes an d u n de r de v e l o p m e n t i n A b u D h a b i, A l g e r i a, E g y p t, I s rae l, I t a l y, P o r t u ga l, S pa i n, an d M o r o c c o. A g r o w i n g n u m be r o f t hese f u t u re C SP p l a n ts w i l l i n c l u de t he r m a l s t o ra ge t o a l l o w o pe ra t i o n i n t o t he e ve n i n g h o u rs. F o r e xa m p l e, t he A n d as o l-1 p l a n t i n S pa i n has m o r e t ha n se ve n h o u rs o f f u l l-l o a d t he r m a l st o ra ge ca pa b i l i t y, an d a 280 M W p l a n t i s p l a n ne d i n A r i z o na w i t h s i x h o u rs st o ra ge (RE N 2 1, 2009).

Figure : Development and implementation of the C S P technology (Source: Meyer, 2009)

T h e C SP i n d us t r y sa w m a n y ne w en t ra n ts i n te r ms o f m a n u f a c t u r i n g f a c i l i t i es i n 2008. A c t i v e p r o j e c t de ve l o pe rs g r e w t o i n c l u de A u s r a, B r i g h t S o u r ce E ne r g y, eSo la r, F P L E ne r g y, I n f i n i a, S o pe r g y, an d S t i r l i n g E ne r g y S ys te ms i n t he U n i t e d S ta tes; A b e n g o a S o l a r, A c c i o na, I b e r d r o l a R e n o v a b l es, an d Sene r i n S pa i n; an d S o l a r M i l l e n n i u m i n G e r m a n y. A u s r a a ls o o pe ne d a m a n u f a c t u r i n g f a c i l i t y i n t he

U S sta te o f N e v a da t ha t w i l l be g i n t o p r o d u ce 700 M W pe r y ea r o f C SP c o m p o n e n ts b y m i d-2009.Sc h o t t S o l a r o f G e r m a n y o pe ne d a m a n u fa c t u r i n g p l a n t i n S pa i n an d is c o ns t r u c t i n g a s i m i l a r p l a n t i n N e w M e x i c o t o m a k e re ce i v e r t u bes. R i o G l ass S o l a r o pe ne d a m a n u f a c t u r i n g p l a n t i n S pa i n f o r t r o u g h m i r r o r s, an d F l a be g o f G e r m a n y an n o u n ce d p l a ns t o b u i l d a pa ra b o l i c m i r r o r f a c t o r y i n t he U n i t e d S ta tes (RE N 2 1, 2009). T h ese i n d us t r y t re n ds su p p o r t t h e en v i sa ge d m a r k e t de v e l o p m e n ts; e x pe c te d t o rea c h 20 G W P b y 2020 an d 1 60 G W P b y 2030 (see F i g u r e 47).

Figure : Expected C S P market development (Source: Meyer, 2009)

4.4. CS P systems – driversFee d-i n-ta r i f f s t ha t a re d i r e c te d t o w a r ds C SP te c h n o l o g i es spec i f i c a l l y, ha ve bee n m a j o r d r i v e rs f o r t hese s ys te ms (see Ta b l e 1 5). T h e d r i v e be h i n d t he f ee d-i n-ta r i f f s has bee n t he pe r ce p t i o n t ha t b y i ns ta l l i n g C SP s ys te ms w o u l d (W W G and M M A , 2008): m e e t ra p i d l y g r o w i n g e le c t r i c i t y de ma n d, p r o v i d i n g t he h i g hes t ca pac i t y d u r i n g u t i l i t y pea k l o a ds, na me l y d i v e r s i f y i n g ene r g y su p p l y ; re d u ce t he l o a d o n l o n g d i s ta n ce t ra ns m i ss i o n l i n es; m ee t na t i o na l an d re g i o na l r e ne w a b l e ene r g y p o r t f o l i o sta n da r ds; re d u ce t he de ma n d f o r an d p r i c e p ressu re o n n o n-re ne w a b l e ene r g y res o u r ces; i m p r o v e an d/or m a i n ta i n a i r q ua l i t y ; an d c r ea te ne w j o b s an d ec o n o m i c o p p o r t u n i t y. F u r t h e r m o r e, a l t h o u g h C SP s ys te ms, i n ge ne ra l, c os ts m o r e t o da y t ha n o t he r re ne w a b l e o p t i o n s suc h as w i n d, t he re a re se ve ra l r i s k-re la te d reaso ns f o r l a r g e-sca le u t i l i t i es t o sh o w i n t e res t i n t hese s ys te ms. F o r e xa m p l e (W W G and M M A , 2008):

• T h e r m a l s t o ra ge o r t he h y b r i d i z a t i o n o f C SP s ys te ms w i t h na t u r a l gas a v o i ds t he p r o b l e ms o f so la r i n t e r m i t t e n c y an d a l l o w s t he p l a n t t o d i s pa t c h p o w e r t o t he l i n e w h e n i t i s nee de d.

• T h e p l a c i n g o f C SP p l a n ts ca n re d u ce g r i d c o n ges t i o n an d i n c r ease g r i d r e l i a b i l i t y.

• L a r ge ce n t ra l l y-l o ca te d p o w e r p l a n ts a re t he t y pes o f s ys te ms t ha t t he u t i l i t i es ha v e o pe ra te d f o r y ea rs an d w i t h w h i c h t he y a re m o s t c o m f o r t a b le.

• O n ce t he C SP p l a n t i s b u i l t, i t s ene r g y c os ts a re f i x e d; t h i s s ta n ds i n c o n t ras t t o f o ss i l f u e l l e d p l a n ts t ha t ha ve e x pe r i e n ce d l a r g e f l u c t u a t i o ns i n f u e l p r i c es d u r i n g t he l as t se ve ra l y ea rs.

Table : Feed-in-tariffs that support CSP developments in selected countries (Source: W W G and M M A, 2008)

Country Support measures

S pa i n T h e f ee d-i n ta r i f f r e g u l a t i o ns o f R o y a l D e c r ee 436/2004 ha ve bee n r e f i ne d w i t h t he re ce n t R o y a l D e c r ee 66 1 f r o m 2007. T h e p r i m a r y c han ge w i t h r es pe c t t o R D 436 i s t he de c o u p l i n g f r o m t he m a r k e t r e f e re n ce p r i ce, w h i c h r ose w i t h o i l p r i ce i n c r eases an d au t o m a t i ca l l y i n c r eased r e ne w a b l e ta r i f f s w i t h t he o i l p r i ce. A f i x e d ta r i f f o f 0.269375 E u r o/k W h is g r a n te d f o r C o n ce n t r a t i n g S o l a r P o w e r (CSP) p l a n t s u p t o 50 M W f o r 25 yea rs, i n c r eas i n g y ea r l y w i t h i n f l a t i o n m i n us 1 pe r ce n ta ge p o i n t. T h e C SP tar ge t w as i n c r ease d t o 500 M W b y 20 10.

P o r t u ga l A ne w f ee d-i n ta r i f f f o r so l a r e le c t r i c i t y w as p u b l i s he d i n P o r t u g a l i n 2007, g r a n t i n g 0.27 €/k W h f o r C SP p l a n t s u p t o 1 0 M W an d 0. 16-0.20 €/k W h f o r C SP p l a n t s be y o n d 1 0 M W.

F r a n ce A ne w f ee d-i n ta r i f f f o r so l a r e le c t r i c i t y w as p u b l i s he d i n F r a n ce o n Ju l y 26, 2006, g r a n t i n g 0.30 €/k W h p l us an e x t r a 0.25 €/k W h i f i n t e g r a te d t o a b u i l d i n g. T h i s ta r i f f i s l i m i t e d t o so l a r o n l y i ns ta l l a t i o ns w i t h l ess t ha n 1 2 M W capa c i t y an d l ess t ha n 1 500 h o u r s/yea r o pe r a t i o n. F o r p r o d u c t i o n o v e r t h i s l i m i t t he ta r i f f i s 0.05 €/k W h.

G r ee ce L a w 3468/2006 G e ne ra t i o n O f E l e c t r i c i t y U s i n g R e ne w a b l e E n e r g y S o u r ces A n d H i g h-E f f i c i e n c y C o g e ne ra t i o n O f E l e c t r i c i t y A n d H e a t A n d M i s ce l l a ne o us P r o v i s i o ns (Of f i c i a l G a ze t t e A ’ 1 29) w as p u b l i s he d i n 2006 an d g r a n t s so l a r ener g y e x p l o i t e d i n u n i t s e m p l o y i n g a tec h n o l o g y o t he r t ha n t ha t o f p h o t o v o l t a i cs w i t h an i ns ta l l e d capa c i t y u p t o 5 M W e0.25 €/k W h o n t he m a i n l a n d an d 0.27 €/k W h o n n o n-i n t e r c o n ne c te d is l a n ds.

I s r ae l T h e I s rae l M i n i s t r y o f N a t i o n a l I n f r as t r u c t u r es, w h i c h is r es p o ns i b l e f o r t he ener g y sec t o r, de c i de d i n 2002 t o i n t r o d u ce t o t he I s r ae l e le c t r i c i t y m a r k e t C SP as a st r a t e g i c i n g r e d i e n t, w i t h a m i n i m a l p o w e r u n i t o f 1 00

M W e. I n 2006, I s r ae l P u b l i c U t i l i t i es A u t h o r i t y ’s N e w Fee d-i n I n ce n t i v es F o r S o l a r-D r i v e n I n d e pen de n t P o w e r P r o d u c e r s w e r e p u b l i s he d, be i n g v a l i d as f r o m Se p t e m be r 3, 2006 f o r a 20 y ea r pe r i o d. F o r p l a n t s w i t h i ns ta l l e d ca pac i t y l a r ge r t ha n 20 M W e t he ta r i f f f o r t he so l a r pa r t o n l y is ap p r o x i m a te l y 1 6.3 U S cen ts/k W h (No v 2006). M a x i m u m a l l o w e d f oss i l b a c k-u p is 30 % o f t he ene r g y p r o d u c ed i n t he p l a n t. F o r s ma l l e r p l a n t s be l o w 20 M W i n t he ra n ge o f 1 00 k W t o 20 M W , f o r t he f i r s t 20 y ea r s pe r i o d t he ta r i f f i s ap p r o x i m a t e l y 20.4 U S ce n t s/k W h.

Figure : S cenario of reducing L E C for HT ST electricity using the learning curve approach (Source: W W G and M M A, 2008)

N e v e r t he less, t he l ea r n i n g c u r v e o f C SP s ys te ms see ms t o ha v e a s ma l l e r s l o pe c o m pa re d t o P V (see F i g u r e 48), an d t he i n d u s t r y d r i v e i s f o r c os t re d u c t i o ns t h r o u g h p l a n t sca le-u p (20 %/48 %), v o l u m e p r o d u c t i o n (26 %/28 %) and te c h n o l o g i c a l ad v a n ce (54 %/24 %) (cf. Ta b l e 1 6, F i g u r e 49 an d Ta b l e 1 7).

Table : Characteristics of C S P systems (Source: W W G and M M A, 2008)

Parabolic trough Central receivers D ish Stirling

S i ze 30 – 320 M W * 1 0 – 200 M W * 5 – 25 k W*

O p e r a t i n g te m pe ra t u r e 390º C 565º C 750º C

A n n u a l ca pac i t y f a c t o r** 23 – 50 % * 20 – 77 % * 25 %

Pea k e f f i c i e n c y 20 % (d) 23 % (p) 29.4 % (d)

N e t an n ua l e f f i c i e n c y 1 1 (d’) – 1 6 % * 7 (d’) 20 % * 1 2 – 25 (p) % *

C o m m e r c i a l stat us

T e c h. de v e l o p m e n t r i s k

S t o r a ge a va i l a b l e

H y b r i d des i g ns

C o m m e r c i a l l y

a va i l a b l e

L o w

L i m i t e d

Y es

S ca l e-u p

de m o n s t r a t i o n

M e d i u m

Y es

Y es

P r o t o t y p e

de m o ns t r a t i o n

H i g h

B a t t e r y

Y es

C o s t

$/m 2

$/W

$/W p***

630 – 275*

4.0 – 2.7*

4.0 – 1 .3*

475 – 200*

4.4 – 2.5*

2.4 – 0.9*

3 100 – 320*

1 2.6 – 1 .3*

1 2.6 – 1 . 1*

* V a l ues i n d i ca te c ha n ges o v e r t he 1 997 t o 2030 t i m e f r a me.

** I n c r eases i n ca pac i t y f a c t o r d u e t o t he use o f t he r m a l s t o ra ge.

*** R e m o v es t he e f f e c t o f t he r m a l s t o r a ge (or h y b r i d i z a t i o n f o r D i s h S t i r l i n g).

(p) = p re d i c t e d; (d) = de m o ns t r a te d; (d’) = has bee n de m o ns t r a te d – y ea rs a re p r e d i c t e d v a l ues.

Figure : L E C predictions for parabolic troughs and central receivers (Source: Sargent & Lundy Consulting Group, 2003)

Table : I nstalled and predicted capacities for C S P technologies ( M W e) (Source: Fluri et al., 2008)

CS P system Installed(2008) P redicted(2018)

Pa ra b o l i c t r o u g h 4 1 8 3528

C e n t r a l r ece i v e r s 1 1 1 3 53

L i n ea r F r es ne l 0 477

D i s h S t i r l i n g < 2 800

T h e t y p i c a l c os t b r ea k d o w n o f a C SP s ys te m i s sh o w n i n F i g u r es 50 an d 5 1. M u c h o f t he c u r re n t R & D e f f o r t i s d ue t o a m a r k e t p us h f r o m t he m a te r i a l m a n u f a c t u r i n g sec t o rs, as w e l l as a m a r k e t p u l l f r o m t he C SP m a n u f a c t u r i n g sec t o r f o r s ys te m c o m p o n e n ts. I t i s a t t h i s i n te r f a ce t ha t t he m u c h c os t re d u c t i o ns a re e x pe c te d t o o p t i m i se t he C SP v a l u e c ha i n (see F i g u r e 52 an d A p p e n d i x A).

Figure : Cost breakdown of a typical C S P system (Sargent & Lundy Consulting Group, 2003)

Figure : Comparison of investment breakdown of two 50 M W parabolic trough plants: thermal oil with 3 hours storage (left), direct steam generation no storage (right)

(Source: P itz-Paal et al., 2005)

Figure : S i mplified C S P value chain (Source: Gereffi et al., 2008)

4.5. Solar chimneyT h e c os ts o f d i f f e re n t c o n f i g u r a t i o ns o f t h e c o n v e n t i o na l so la r c h i m n e y ha v e bee n de r i v e d t h r o u g h o p t i m i sa t i o n m o de l s (Pre t o r i u s, 2007). S u c h m o de l s sh o w h i g h v a r i a t i o ns i n resu l t s, w i t h a l e ve l i se d e le c t r i c i t y c os t (LE C) o f be t w ee n 0. 1 an d 0.43 €/k W h (Fl u r i e t a l., 2009). T h e i n v es t m e n t u n ce r ta i n t y o f t h i s te c h n o l o g y t he re f o re re ma i n s h i g h an d l a r ge-sca le de m o ns t ra t i o n i s nee de d be f o re t he i n te r na t i o na l f u t u r e m a r k e t p o te n t i a l (tre n ds an d d r i v e rs) o f t he te c h n o l o g y ca n be esta b l i s he d.

4.6. Solar pondsA s sta te d ab o v e, t h i s te c h n o l o g i ca l s ys te m has t he l o w es t c os t o f a l l t he s ys te ms (St i ne an d G e ye r, 200 1), an d t he te c h n o l o g y has bee n a va i l a b le f o r o v e r t h ree de ca des. H o w e v e r, t h e re q u i r e m e n t f o r l o w-c os t, l a r ge l a n d a reas an d t he a va i l a b i l i t y o f w a te r, as w e l l as t he (rela t i v e l y) l o w p o w e r o u t p u ts, ha v e m a de t he f u r t h e r de v e l o p m e n t an d ap p l i ca t i o n o f t hese s ys te m u na t t r a c t i v e at a g l o ba l l e ve l. C e r ta i n r u r a l ap p l i ca t i o ns, o n t he A f r i c a n c o n t i n e n t, m a y be a p oss i b i l i t y.

5. Thermal heating and cooling applications

5.1. General trends and driversT h e t re n ds an d d r i v e r s i n t he n o n-t ra c k i n g t he r m a l ap p l i c a t i o n s sec t o r a re d o m i n a te d b y t he p o l i c y l a n ds ca pe (RE N 2 1, 2009), w h i c h has ca use d so la r t he r m a l hea t, apa r t f r o m w i n d, t o d o m i n a te t he t o ta l r e ne w a b l e ene r g y p o r t f o l i o (see F i g u r e 53).

Figure : Renewable energy - total capacity in operation and produced energy (2007) (Source: Holm, 2009)

M a n da tes f o r so la r h o t w a te r/hea t i n g an d o t he r f o r ms o f re ne w a b l e h o t w a te r/hea t i n g i n ne w c o ns t r u c t i o n ac ce le ra te d d u r i n g 2008, f o l l o w i n g t he e xa m p l e o f S pa i n, t he f i r s t c o u n t r y t o m a n d a te so la r w a te r hea t i n g at b o t h na t i o na l an d l o ca l l e ve l s. A w i d e v a r i e t y o f o t he r p o l i c y ad d i t i o n s an d c ha n ges f o r re ne w a b l e hea t i n g a ls o o c c u r r e d d u r i n g 2007/2008. E x a m p l es a re as f o l l o w s (RE N 2 1, 2009):

• C h i na has an o b l i g a t i o n t ha t n o e le c t r i c i t y ca n be use d t o p r o d u ce h o t w a te r.

• S y r i a m a n da te d b u i l d i n g des i g ns su i ta b le f o r so l a r h o t w a te r.

• N e w D e l h i m a n da te d so la r h o t w a te r f o r a w i d e v a r i e t y o f ne w i n s t i t u t i o na l, c o r p o r a te, an d res i d e n t i a l b u i l d i n gs.

• I n G e r m a n y, t he sta te o f B a d e n-W ü r t t e m be r g enac te d t he c o u n t r y ’s f i r s t re ne w a b l e hea t i n g l a w re q u i r i n g t ha t a l l ne w b u i l d i n gs p r o d u ce 20 pe r ce n t o f t he i r w a te r an d space hea t i n g re q u i r e m e n ts w i t h re ne w a b l es; e x i s t i n g b u i l d i n gs ha ve t w o y ea rs t o m a ke t he t ra ns i t i o n t o 1 0 pe r ce n t. A t t he f e de ra l l e ve l i n G e r m a n y, a ne w m i n i m u m re q u i r e m e n t f o r b o t h h o t w a te r an d space hea t i n g su p p l y f r o m re ne w a b l es (inc l u d i n g so la r, b i o gas, b i o m ass, an d g r o u n d-so u r ce hea t p u m ps) i n ne w b u i l d i n gs en te re d i n t o f o r ce a t t he sta r t o f 2009, an d p u b l i c f u n d s f o r c o n v e r t i n g e x i s t i n g b u i l d i n gs w e r e i n c reased t o €500 m i l l i o n ($650 m i l l i o n).

• N o r w a y re q u i r es re ne w a b l e h o t w a te r hea t i n g i n p u b l i c b u i l d i n gs g r ea te r t ha n 500 sq ua re m e te rs.

• T h e U n i t e d S ta tes e x te n de d a f e de ra l 30 pe r ce n t ta x c r e d i t t h a t ap p l i es t o so la r h o t w a te r t h r o u g h 20 1 6 an d e l i m i n a te d a $2000 ca p f o r res i d e n t i a l so la r h o t w a te r. T h e sta te o f H a w a i i w i l l re q u i r e so la r h o t w a te r i n a l l ne w s i n g l e-f a m i l y h o mes c o ns t r u c te d sta r t i n g i n 20 10.

• C a na da ad o p te d a 25 pe r ce n t i n v es t m e n t su bs i d y.

• I r e l a n d sta r te d t o p r o v i d e g r a n ts f o r h o m es an d p u b l i c an d c o m m e r c i a l b u i l d i n gs.

• L u x e m b o u r g be ga n t o p r o v i d e 40 t o 50 pe r ce n t su bs i d i es f o r so la r an d ge o t he r m a l.

• M e x i c o an d a n u m be r o f o t he r c o u n t r i es de v e l o pe d ne w te c h n i ca l s ta n da r ds. M e x i c o a ls o esta b l i s he d a “g ree n m o r t g a ge” p r o g r a m t o f i n a n ce ne w so la r h o t w a te r i ns ta l l a t i o n s an d o t he r w a te r an d ene r g y c o nse r va t i o n m eas u res.

• M o r o c c o l o w e r e d V A T o n so la r h o t w a te r s ys te ms an d p l a n ne d t o enac t m a n da tes i n 2009.

• Po l a n d esta b l i s he d an o b l i g a t i o n f o r u t i l i t i es t o p u r c hase re ne w a b l e hea t i n ad d i t i o n t o t he e le c t r i c i t y f ee d-i n ta r i f f .

Figure : I nstalled capacity per 1000 inhabitants (k Wth /a) (Source: Holm, 2009)

F i g u r e 54 su m ma r i ses so me o f t he k e y m a r k e t de v e l o p m e n ts i n te r ms o f so la r w a te r hea t i n g (Ho l m, 2009). O n e d r i v e r f o r t he u p ta k e o f so la r w a te r hea t i n g i n de ve l o p i n g c o u n t r i es has bee n t he C l ea n D e v e l o p m e n t M e c h a n i s m (CD M) o f t he K y o t o P r o t o c o l, an d espec i a l l y p r o g r a m m a t i c C D M , w h i c h i s ap p r o p r i a te w h e r e a l a r g e n u m b e r o f s ma l l u n i ts a re ge o g r a p h i c a l l y d i s pe rse d an d o c c u r o v e r a pe r i o d o f t i m e (Abe l, 2009); M e x i c o has t he f i r s t re g i s te re d p C D M g l o ba l l y, an d T u n i s i a an d V i e t na m are i n t he p r o cess o f v a l i d a t i n g p C D M s f o r so la r w a te r hea te r i ns ta l l a t i o n s. S u c h f u n d i n g o p p o r t u n i t i es ca n su p p o r t e x i s t i n g su bs i d y sche mes t o f i n a n ce so l a r w a te r hea te r i ns ta l l a t i o n s. H o w e v e r, p r o m o t i n g re ne w a b l e hea t i n g t h r o u g h f i n a n c i a l i n ce n t i v es ta ke n f r o m t he p u b l i c b u d ge t be c o mes m o r e an d m o r e d i f f i c u l t as t he m a r k e t v o l u m es i n c r ease (Ho l m, 2009). T h e d r i v e r t h e n f o r p r o m o t i n g a so la r w a te r hea t i n g i n d us t r y has bee n e m p l o y m e n t c r ea t i o n; base d o n da ta c o l l e c te d f r o m de ta i l e d c o u n t r y r e p o r t s, t h e j o bs c r ea te d b y t he p r o d u c t i o n, i ns ta l l a t i o n an d m a i n te na n ce o f so la r t he r m a l u n i t s i s es t i m a te d t o be 200,000 w o r l d w i d e (Ho l m, 2009). N e v e r t h e l ess, t he k e y t o suc cess f u l r o l l o u t re ma i ns t he c os t e f f i c i e n c y o f so la r w a te r hea te r u n i ts (Pear l, 2009), as w e l l as ca pac i t y b u i l d i n g (see F i g u r e 55). T h e l a t te r i s e x pe c te d t o ta ke u p t o 5 y ea rs t o esta b l i s h, w i t h i n te l l i g e n t f i n a n c i n g sc he mes (Ho l m, 2009).

Figure : E lements for the successful implementation of a S W H program me (Source: Holm, 2009)

Ve r y l i t t l e p o l i c y has bee n i n t r o d u ce d i n te r na t i o na l l y t o ad d r ess space c o o l i n g, a l t h o u g h t h i s i s l i k e l y t o f o l l o w t he space hea t i n g t re n ds an d d r i v e r s, espec i a l l y i n t he w a r m e r c l i m a tes an d w i t h p r e d i c t i o ns o f c l i m a t e c ha n ge. L a r ge c o m m e r c i a l an d p u b l i c b u i l d i n gs ha ve a l rea d y seen t he i ns ta l l a t i o n o f so la r c o l l e c t o r s f o r c o o l i n g (Ho l m, 2009). S i m i l a r l y, a l t h o u g h p o l i c y has n o t d r i v e n so la r res o u r ce ap p l i c a t i o n i n t he ag r i c u l t u r a l an d i n d us t r y sec t o r s, t h ese sec t o r s ha ve seen t he be ne f i ts o f c o ns i d e r i n g an d ap p l y i n g t he res o u r ce. F o r e xa m p l e (Ho l m, 2009): space hea t i n g f o r f a c t o r i es; stea m ge ne ra t i o n f o r p r o d u c t i o n p r o cesses; d r y i n g ap p l i c a t i o n s; an d desa l i na t i o n.

A l ea r n i n g f a c t o r o f 20 % pe r d o u b l i n g o f ca pa c i t y a t t h e c o u n t r y l e v e l i s sta te d (IE A, 2009). T h e E u r o pea n S o l a r T h e r m a l Te c h n o l o g y P l a t f o r m is e ve n m o r e o p t i m i s t i c, sta t i n g t ha t o v e r t he l as t de ca de, i n v es t m e n t c os t re d u c t i o n s o f a r o u n d 20 % ha v e bee n o bse r ve d f o r eac h 50 % i n c r ease i n t he t o ta l i ns ta l l e d ca pac i t y o f so la r w a te r hea te rs (ES T TP, 2009). C o m b i-s ys te ms (co m b i ne d so la r t he r m a l s ys te ms f o r d o m es t i c w a te r hea t i n g an d space hea t i n g) i n pa r t i c u l a r ha v e be ne f i t e d f r o m t hese c os t r e d u c t i o ns, an d ha ve i n c r eased t he i r m a r k e t sha re. F u r t h e r R D & D i n v es t me n t ca n he l p t o d r i v e t hese c os ts d o w n f u r t h e r (see F i g u r e 56). C o s t r e d u c t i o n s a re e x pec te d t o ste m f r o m:

• D i r e c t b u i l d i n g i n t e g r a t i o n (façade an d r o o f) o f c o l l e c t o rs;

• I m p r o v e d m a n u f a c t u r i n g p r o cesses; an d

• N e w ad va n ce d m a te r i a ls, su c h as p o l y m e rs f o r c o l l e c t o r s.

F u r t h e r m o r e, c os t re d u c t i o n p o te n t i a l ca n be seen i n i n c reas i n g p r o d u c t i v i t y b y t he m ass p r o d u c t i o n o f sta n da r d i se d (ki t) s ys te ms, w h i c h re d u ce t he nee d f o r o n-s i te i n s ta l l a t i o n an d m a i n te na n ce w o r k s.

Figure : Development of specific costs and installed capacity for small solar thermal systems (forced circulation) in central E urope

(Source: I T W, University Stuttgart, quoted in ESTT P, 2009)

A d v a n ce d ap p l i c a t i o ns, suc h as so la r c o o l i n g an d a i r c o n d i t i o n i n g, i n d us t r i a l ap p l i ca t i o ns an d desa l i n a t i o n/wa te r t rea t m e n t, a re i n t he ea r l y s ta ges o f de v e l o p me n t, w i t h o n l y a f e w h u n d re d o f f i r s t ge ne ra t i o n s ys te ms i n o pe ra t i o n. C o ns i d e ra b le c os t re d u c t i o ns ca n be ac h i e ve d i f R & D e f f o r t s a re i n c r eased o v e r t he ne x t f e w y ea rs (see F i g u r e 57).

Figure : I ndication of the current state of deployment of solar thermal applications from development to application in the m ass m arket

(Source: A E E I NT EC quoted in ESTT P, 2009)

E S T T P (2009) assu me t ha t te c h n o l o g i ca l p r o g r ess an d ec o n o m i es o f sca le w i l l l ea d t o a r o u n d a 60 % re d u c t i o n i n c os ts b y 2030. Ta b l e 1 8 sh o w s a ra n ge o f p r i ces f o r hea t ge ne ra te d b y a so la r t he r m a l s ys te m, c o m p a r e d t o t he c u r r e n t p r i ce o f gas an d e le c t r i c i t y f o r t he en d user, an d t he p r i ce p r o j e c te d f o r 2030. I n f l a t i o n i s n o t ta ke n i n t o c o ns i de ra t i o n.

Table : P rices to generate heat by solar thermal systems (Source: ESTT P, 2009)

Cost in €-cent per k W h

Today 2030

Central Europe Southern Europe Central Europe Southern Europe

S o l a r T h e r m a l 7 – 1 6 5 – 1 2 3 – 6 2 – 4

N a t u r a l gas 8.5 – 29 1 7 – 58

E l e c t r i c i t y 7 – 33 1 4 – 66

T h e c os ts o f so la r hea t i n c l u de a l l ta xes, i n s ta l l a t i o n an d m a i n te na n ce. T h e sp read is w i d e, be ca use t he t o ta l c os ts v a r y st r o n g l y, de pe n d i n g o n f a c t o r s suc h as:

• Q u a l i t y o f p r o d u c ts an d i n s ta l l a t i o n;

• Ease o f i n s ta l l a t i o n;

• A v a i l a b l e so la r ra d i a t i o n (lat i t u de, n u m be r o f su n n y h o u rs, o r i e n ta t i o n an d t i l t i n g o f t he c o l l e c t o r s);

• A m b i e n t te m pe ra t u re; an d

• Pa t te r ns o f use de te r m i n i n g t he hea t l o a d.

5.2. Trends and drivers for industrial applicationsA l t h o u g h t he res i d e n t i a l sec t o r o f f e r s a h u ge p o te n t i a l f o r so la r t he r m a l ap p l i ca t i o ns, t he i n d us t r i a l sec t o r sh o u l d n o t be i g n o re d. T h e f i n d i n gs o f t h e E u r o p ea n S o l a r T h e r m a l I n d u s t r y Fe de ra t i o n (ES T I F, 2006) w e r e:

• I n O E C D c o u n t r i es, i n d u s t r y acc o u n ts f o r 30 % o f ene r g y c o ns u m p t i o n;

• I n t he E U , t w o-t h i r ds o f t h i s 30 % c o ns i s ts o f hea t ra t he r t h a n e le c t r i ca l ene r g y; an d

• A b o u t 50 % o f t he i n d us t r i a l hea t de ma n d l i es be l o w 250° C, a l a r g e p r o p o r t i o n o f w h i c h ca n be su p p l i e d b y c u r re n t o r c l ose-t o-m a r k e t so la r t h e r m a l te c h n o l o g i es.

T h ese f i n d i n g s w e re ec h oe d b y W e i ss an d R o m m e l (2008). A n o t he r r e p o r t (Vann o n i e t a l, 2008), w h i c h f u r t h e r desc r i b es i n d us t r i a l hea t de ma n d i n te m pe ra t u r e ra n ges:

• B e l o w 400° C: 57 % ;

• B e l o w 1 00 ° C: 30 %; an d

• B e l o w 250° C (in se ve ra l i n d u s t r i a l sec t o r s): 60 % o f t he t o ta l f i g u r e.

F i g u r e 58 sh o w s o f i n d us t r i a l hea t de ma n d sha re b r o k e n d o w n b y te m pe ra t u re l e v e l an d i n d u s t r i a l sec t o r f o r 32 E u r o pea n c o u n t r i es: E U 25 + B u l g a r i a, R o m a n i a, T u r k e y, C r oa t i a, I c e la n d, N o r w a y an d S w i t ze r l a n d, w h i l e F i g u r e 59 sh o w s a s i m i l a r b r ea k d o w n f o r t h e I b e r i a n Pen i ns u la.

Figure : S hare of industrial heat demand by temperature level and industrial sector (Source: Vannoni et al., 2008)

Figure : S h are of industrial heat demand by temperature level for some industrial sectors which require low temperature heat

(Source: P OS H I P, 2001)

Va n n o n i e t a l. (2008) c o n c l u de t ha t t h e k e y sec t o rs a re f o o d (inc l u d i n g w i n e an d be v e ra ge), te x t i l e, t ra nsp o r t eq u i p m e n t, m e ta l an d p l as t i c t rea t me n t, an d c he m i ca l. T h e a reas o f ap p l i c a t i o n w i t h t he m o s t su i ta b le i n d u s t r i a l p r o cesses i n c l u de c l ean i n g, d r y i n g, e va p o r a t i o n an d d i s t i l l a t i o n, b l a n c h i n g, pas te u r i sa t i o n, ste r i l i sa t i o n, c o o k i n g, m e l t i n g, pa i n t i n g, an d su r f a ce t rea t me n t. T h e y g o o n t o sa y t ha t space hea t i n g an d c o o l i n g o f f a c t o r y b u i l d i n gs sh o u l d be i n c l u de d a m o n g t he m o s t p r o m i s i n g ap p l i c a t i o n s. I n t hese sec t o rs, so la r t he r m a l hea t c o u l d be f r u i t f u l l y use d, as t he hea t de ma n d is re ma r k a b l e an d m o r e o r l ess c o n t i n u o us t h r o u g h o u t t h e y ea r; an d t he te m pe ra t u r e l e v e l re q u i r e d b y so me o f t he p r o cesses i s c o m pa t i b l e w i t h t he e f f i c i e n t o pe ra t i o n o f so la r t he r m a l c o l l e c t o r s.

Table : I ndustrial heat demand and solar process heat potential for selected countries and for E U25

(Vannoni et al, 2008)

Country I ndustrial heat demand

Solar process heat potential:

Solar process heat / I nd. heat

Potential in terms of

Potential in terms of

low & medium temperature demand

capacity collector area

P J /year P J /year % G W th M io m 2

A u s t r i a 1 3 7 5.4 3.9 3 4.3

S pa i n 493* 1 7.0 3.4 5.5 – 7 8 – 1 0

P o r t u ga l 90* 4.0 4.4 1 .3 – 1 .7 1 .9 – 2.5

I t a l y 857 3 1.8 3.7 1 0 1 4.3

N e t he r l a n ds 46 1 .95 3.2 0.5 – 0.7 0.8 – 1

E U 25 6,88 1 258.2 3.8 1 00 – 1 25 1 43 – 1 80

Va n n o n i e t a l. (2008) sta te t ha t ab o u t 90 o pe ra t i n g so la r t he r m a l p l a n ts f o r p r o cess hea t e x i s t w o r l d w i d e, w i t h a t o ta l ca pac i t y o f ab o u t 25 M W t h (35,000 m ²). T h i s i s a v e r y s ma l l f r a c t i o n (0.02 %) o f t he t o ta l so la r t h e r m a l ca pac i t y i n s ta l l e d w o r l d w i d e, w h i c h eq ua ls 1 1 8 G W t h (most l y d o mes t i c so la r w a te r hea t i n g, p o o l hea t i n g an d space hea t i n g). F i g u r es 60 an d 6 1 sh o w t he d i s t r i b u t i o n o f ca pa c i t y b y i n d us t r y an d c o u n t r y, respec t i v e l y. T h e l o w f i g u r e o f 0.02 % o f t he i ns ta l l e d so la r t h e r m a l ca pa c i t y f o r i n d us t r i a l p r o cess hea t c o m p a re d t o d o m es t i c w a te r hea t i n g sh o w s a g r ea t o p p o r t u n i t y f o r i m p r o v e me n t.

Figure : Solar industrial process heat plants - distribution by industry sector (Source: Vannoni et al., 2008)

Figure : Solar industrial process heat plants - distribution by country (Source: Vannoni et al., 2008)

T h e t re n ds i n h i g h te m pe ra t u re, c o n ce n t ra te d t he r m a l w i t h t ra c k i n g ap p l i ca t i o ns has l a r g e l y bee n t h r o u g h c o m b i ne d hea t an d p o w e r (CHP) s ys te ms t ha t a re l o ca te d at i n d us t r i a l an d v e r y l a r ge c o m m e r c i a l f a c i l i t i es; t hese s ys te ms ge ne ra te b o t h p o w e r an d stea m. T h e stea m is used o n s i te (or nea r b y) f o r p r o cess hea t o r space c o n d i t i o n i n g, an d t he p o w e r m a y be use d o n s i te o r so l d t o t he g r i d (E A C, 2009). T h ese p l a n ts ca n ha v e v e r y h i g h e f f i c i e n c y (45 % t o 80 %) be ca use m u c h o f t he hea t i s use d an d n o t w a s te d. I n 2006, C H P s ys te ms ge ne ra te d ab o u t 322 te ra w a t t h o u rs (T W h) o f e le c t r i c i t y i n t he U n i t e d S ta tes, acc o u n t i n g f o r 7.9 % o f ne t ge ne ra t i o n t ha t y ea r (E A C, 2009). Se ve ra l st u d i es ha v e est i m a te d t ha t t h e a m o u n t o f p o w e r f r o m C H P c o u l d be i n c reased b y m o r e t ha n 50 % (Sh i p le y et a l., 2009). H o w e ve r, l i t t l e i n f o r m a t i o n i s a va i l a b le i n te r ms o f n o n-re ne w a b l e reso u r ce usage, f o r p r o cess hea t, w h i c h ca n be re p la ce d o v e r t i m e, b u t p r o j e c t i o ns a re l a r ge q ua n t i t i es (Roos, 2009). N e v e r t h e less, rea l i z i n g t h i s p o t e n t i a l w i l l r e q u i r e t he o v e r c o m i n g o f a v a r i e t y o f ba r r i e rs, ra n g i n g f r o m h os t-s i te re l u c ta n ce t o ge t i n t o t he p o w e r b us i ness, f l u c t u a t i o n s i n n o n-re ne w a b l e f u e l an d e le c t r i c i t y p r i c es o v e r t i m e, an d p r o b l e m s w i t h en v i r o n m e n ta l re g u l a t i o n s an d i n te r c o n ne c t i o n re q u i r e m e n ts i n so me se r v i c e a reas an d j u r i s d i c t i o n s (E A C, 2009). T h e f u t u re t re n ds an d d r i v e r s, an d c os t i m p l i c a t i o ns, a re su bseq ue n t l y v a g ue.

Figure : F ive thermochemical routes for the production of solar hydrogen (Source: Steinfeld, 2005)

A n u m b e r o f so la r t he r m o c he m i c a l p r o cesses a re be i n g i n v es t i g a te d; m o s t n o t a b l y t he p r o d u c t i o n o f h y d r o ge n as a c l ea n l i q u i d f u e l (see F i g u r e 62). E c o n o m i c assess me n ts (Ste i n f e l d, 2005) ha v e i n d i c a te d t ha t t h e so la r t he r m o c he m i c a l p r o d u c t i o n o f h y d r o ge n ca n be c o m p e t i t i v e w i t h t he e le c t r o l y s i s o f w a te r us i n g so l a r-ge ne ra te d e le c t r i c i t y, an d, u n de r ce r ta i n c o n d i t i o ns, m i g h t be c o m e c o m p e t i t i v e w i t h c o n v e n t i o na l f o ss i l-f u e l-based p r o cesses at t he t he n (2005) f u e l p r i c es, e ve n be f o r e t he ap p l i c a t i o n o f c re d i t f o r C O 2m i t i g a t i o n an d p o l l u t i o n a v o i d a n ce. H o w e v e r, t h e re a re (st i l l) m u c h u n ce r ta i n t i es i n t he v i a b l e e f f i c i e n c i es an d i n v es t me n t c os ts o f t he v a r i o u s c o m p o n e n ts d ue t o t he i r ea r l y sta ge o f de v e l o p me n t an d t he i r ec o n o m y o f sca le; f u r t h e r de v e l o p me n t an d l a r ge-sca le de m o ns t ra t i o n a re w a r r a n te d (Ste i n f e l d, 2005). A l s o, t he m a r k e t p r o j e c t i o ns o f a h y d r o ge n ec o n o m y a re st i l l m u c h de ba te d (N A C, 2004) and i t i s d i f f i c u l t a t t h i s s ta ge t o asce r ta i n t he m a r k e t p u l l t ha t w i l l d r i v e d o w n t he c os ts o f t h ese te c h n o l o g i ca l s ys te ms.

6. The international policy landscapeR E N 2 1 (2009) p r o v i d es a de ta i l e d o v e r v i e w o f h o w t he i n te r na t i o na l p o l i c y l a n dsca pe has t ra ns f o r m e d (so la r) p o w e r an d t he r m a l ap p l i c a t i o n s i n ge ne ra l. O f spec i f i c i m p o r ta n ce is t he f o r m a t i o n o f t he I n te r na t i o na l R e ne w a b l e E ne r g y A g e n c y (IR E N A) d u r i n g 2009. B y A p r i l 2009, 78 c o u n t r i es ha d s i g ne d t he sta t u te o f t h e I R E N A . M e m b e rs i n c l u de m o s t c o u n t r i es o f t he E u r o p ea n U n i o n an d m a n y de ve l o p i n g c o u n t r i es, f r o m A f r i c a t o A s i a-Pac i f i c t o L a t i n A m e r i c a, i n c l u d i n g A r g e n t i na, C h i l e, G h a na, I n d i a, M o r o c c o, t he P h i l i p p i n es, Se ne ga l, S o u t h K o r ea, an d T u n i s i a (see a ls o F i g u r e 63). I R E N A w i l l p r o v i d e ad v i c e an d su p p o r t t o g o v e r n m e n ts w o r l d w i d e o n re ne w a b l e ene r g y p o l i c y, ca pac i t y b u i l d i n g, an d te c h n o l o g y t ra ns fe r. I R E N A w i l l a ls o i m p r o v e t he f l o w o f f i n a n c i n g an d k n o w-h o w an d c o l l a b o r a te w i t h e x i s t i n g r e ne w a b l e ene r g y o r ga n i za t i o ns. I R E N A ’s g oa l i s u l t i m a te l y t o i n c r ease t he sha re o f re ne w a b l e ene r g y w o r l d w i d e. S u c h a de d i c a te d m u l t i l a te ra l age n c y f o r re ne w a b l es has bee n c o ns p i c u o us l y absen t f r o m t he i n te r na t i o na l l a n dsca pe, an d I R E N A ’s f o u n d i n g re f l e c ts a g r o w i n g c o nse ns us a m o n g g o v e r n me n ts a r o u n d t he w o r l d o n t he nee d t o ac t i v e l y su p p o r t t h e e x pa ns i o n o f re ne w a b l e ene r g y.

Figure : S hares and targets for renewable energies (Source: Holm, 2009)

3. SOUT H A F R I C A N M A R K E T P OT E NT I A L A N D B A R R I E R S

T h e p o te n t i a l o f, an d ba r r i e rs f o r, re ne w a b l e ene r g y i n t he S o u t he r n A f r i c a n D e v e l o p me n t C o m m u n i t y (SA D C) re g i o n has bee n i n v es t i g a te d f o r o v e r a de ca de (DBS A an d I S E S, 1 999). A t t he t u r n o f t h e ce n t u r y t he re w e re n o sus ta i na b l e i n ce n t i v es o r su bs i d y sc he mes t o en c o u r a ge l a r g e-sca le r e ne w a b l e ene r g y s ys te ms i n t he r e g i o n. R e ne w a b l e ene r g y te c h n o l o g i es (RETs) ha d t o c o m p e te f o r m a r k e t sha re base d o n ene r g y c os ts t ha t d o n o t i n c l u de an y e x te r n a l i t i es; t h e y re q u i r e d n i c he m a r k e ts t o de l i v e r v i a b l e r e t u r ns o n i n v es t m e n t.

T h e d r i v e r be h i n d t he R E T m a r k e t i n S A D C had ge ne ra l l y bee n de ce n t ra l i se d p o w e r su p p l y (DBS A an d I S E S, 1 9 99). T h e o n l y e x ce p t i o ns w e r e g r i d c o n ne c te d s ma l l h y d r o an d b i o mass-base d e le c t r i c i t y p r o d u ce rs. I n S A D C, w i t h i ts l o w l e v e l s o f pe r ca p i ta ac cess t o n o n-b i o m ass base d ene r g y ca r r i e rs an d pa r t i c u l a r l y e le c t r i c i t y, R E T S ha d bee n i m p l e me n te d as a l eas t c os t te c h n o l o g y i n su p p l y i n g ene r g y t o r u r a l, re m o te an d p o o r sec t o r s o f t h e p o p u l a t i o n, o r t o su p p l y essen t i a l e le c t r i c i t y t o i s o la te d a reas f o r te le c o m m u n i ca t i o n o r m e d i ca l ap p l i c a t i o n s. C o ns i d e r i n g t he l a r ge l y r u r a l na t u r e o f t he re g i o n ’s p o p u l a t i o ns t hese w e r e pe r ce i v e d as s i g n i f i c a n t m a r k e t seg me n ts, an d a ls o spec i f i c a l l y f o r S o u t h A f r i c a (Meh l w a na, 200 1).

S i n ce t he n, h o w e v e r, t h ree m a j o r a reas o f c o n ce r n ha ve bee n ra i sed t ha t a f f e c t t h e ab i l i t y o f S o u t h A f r i c a t o su p p l y m o r e ene r g y t o i t s g r o w i n g p o p u l a t i o n an d ec o n o m y, an d w h i c h w i l l (or sh o u l d) i n f l u e n ce dec i s i o n-m a k i n g (Ban ks an d S c hä f f l e r, 2006):

1 . T h e c u r r e n t h i g h re l i a n ce o n f o ss i l f u e l s i s u ns us ta i na b le i n t he l o n ge r te r m:

• O i l i s r u n n i n g a f i n i t e reso u r ce. M a n y st u d i es su g ges t t h a t w e ha v e rea c he d t he pea k o f p oss i b l e p r o d u c t i o n (ASP O, 2007), an d t he re ha ve a l rea d y bee n s i g n i f i c a n t p r i ce f l u c t ua t i o ns (Tav i v e t a l., 2008).

• A l t h o u g h t he re a re a m p l e rese r ves o f c oa l t o l as t a ce n t u r y o r m o r e a t c u r re n t ra tes, t h i s f u e l w i l l e ve n t u a l l y be c o m e m o r e sca r ce an d m o r e e x pe ns i v e (Tav i v e t a l., 2008), w i t h d i m i n i s h i n g re t u r ns o n ca p i ta l an d ene r g y i n v es te d f o r re c o v e r y o f l ess access i b l e de p os i ts, f o r e xa m p l e t h r o u g h u n de r g r o u n d gas i f i c a t i o n (Zie le n i e w s k i an d B r e n t, 2008).

• L a r ge f l u c t ua t i o ns i n ene r g y p r i ces f o r i n d us t r y an d h o useh o l d s ha v e h u ge ec o n o m i c an d so c i a l c o nse q ue n ces.

• W e sh o u l d n o t s i m p l y b u r n a l l o u r h y d r o-ca r b o n res o u r ces, w h i c h m a y be o f f a r g r ea te r v a l u e an d v a r i e d ap p l i ca t i o n t o o u r c h i l d r e n, an d o u r g r a n d c h i l d r e n.

2. F oss i l f u e l use has a s i g n i f i c a n t ne ga t i v e i m pa c t o n t he l o ca l en v i r o n m e n t. E v e r y M W h o f e le c t r i c i t y ge ne ra te d i n S o u t h A f r i c a re q u i r es an a ve ra ge o f 1 270 l i t r es o f w a te r (near l y 5 000 l i t r es pe r ca p i ta pe r y ea r). C oa l an d b i o m ass b u r ne d i n h o m es an d i n d us t r y ca use p o l l u t i o n, w h i c h a f f e c ts b o t h hea l t h an d

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v e ge ta t i o n. C o a l m i n i n g l ea ds t o en v i r o n m e n ta l de g ra da t i o n w i t h s i g n i f i c a n t c os t i m p l i c a t i o ns t o r e me d i a te m i n i n g a reas (du P less is an d B r e n t, 2006).

3. F oss i l f u e l s a re a l l ca r b o n-based, an d as c u r re n t l y used, t he y resu l t i n t he e m i ss i o n o f g r ee n h o use gas e m i ss i o n i n t o t he a t m os p he re. S o u t h A f r i c a e m i t s i n t he o r de r o f 400 m i l l i o n t o n nes o f ca r b o n d i o x i d e eq u i v a l e n t g r een h o use gases pe r y ear, o r 8.6 1 t o n nes/cap i ta, an d is o ne t he t o p 20 g ree n h o use gas e m i t te rs i n t he w o r l d (Bren t e t a l., 2009). I n t he t o p t h i r t y ec o n o m i es, S o u t h A f r i c a has t he t h i r d h i g hes t C O 2 i n t e ns i t y a f te r R uss ia an d C h i n a (see F i g u r e 64).

Figure : Comparative CO 2intensity of South Africa (Source: Roos, 2009)

Figure : Comparative electricity intensity of South Africa (Source: Roos, 2009)

T h i s i s l a r g e l y be ca use o f t h ree f a c t o r s:

• So u t h A f r i c a has a v e r y h i g h e le c t r i c i t y i n te ns i t y (2n dh i g hes t o f t o p 30 ec o n o m i es, see F i g u r e 65).

• So u t h A f r i c a n e le c t r i c i t y i s 90 % c oa l based. T h e b u r n i n g o f c oa l p r o d u ces nea r l y p u r e l y C O 2, w h i l e t he c o m b us t i o n o f na t u r a l gas resu l t s i n b o t h C O 2an d w a te r.

• C oa l i s b u r n t i n R a n k i n e c y c l e p o w e r sta t i o ns a t ab o u t 35 % e f f i c i e n c y. N a t u r a l gas is b u r n t i n c o m b i ne d c y c l e p o w e r sta t i o ns at be t w ee n 50 an d 60 % e f f i c i e n c y.

T h ese f a c t o r s t r i g ge re d a na t i o na l e f f o r t t o i n v es t i ga te l o n g te r m m i t i g a t i o n scena r i os f o r t he c o u n t r y (SBT, 2007a), an d a ls o spec i f i c scena r i os f o r c lea ne r ene r g y (Ha w an d H u g h es, 2007; Ta v i v e t a l., 2008). W i n k l e r e t a l. (2007) ha v e su bse q ue n t l y es t i m a te d t he t he o r e t i ca l p o te n t i a l f o r r e ne w a b l e ene r g y at ab o u t 280 000 G W h as o p p osed t o t he ta r ge t o f t he na t i o na l D e p a r t m e n t o f M i n e r a l s an d E ne r g y o f 1 0 000 G W h b y 20 1 3 (D M E, 2003), w h i c h i s c u r r e n t l y be i n g re v i se d. N e v e r t h e less, M a r q u a r d et a l. (2008) ha v e ca l c u l a te d t ha t R E Ts c o u l d rea l i s t i ca l l y m a k e u p 1 5 % t he ene r g y m i x f o r S o u t h A f r i c a b y 2020. T h e b u l k o f t h i s p o te n t i a l l i es w i t h so la r ene r g y, a l t h o u g h i t i s re c o g n i se d t ha t a su bs ta n t i a l c o n t r i b u t i o ns a re (st i l l) r e q u i r e d b y sc ie n ce (see F i g u r e 66) be y o n d i de n t i f i c a t i o n o f t h i s reso u r ce i n te r ms o f (SBT, 2007b):

• N e w te c h n o l o g y, na me l y i n v es t i n g i n te c h n o l o g i es f o r t he f u t u r e;

• Peo p l e-o r i e n te d m e as u res, na me l y i n ce n t i v i se d be ha v i o u r c ha n ge; an d

• T h e t ra ns i t i o n t o a l o w-ca r b o n ec o n o m y b y re de f i n i n g S o u t h A f r i c a’s c o m p e t i t i v e ad v a n ta ge.

Figure : Strategic options to get from growth without constraints to the required by science (Source: S B T, 2007b)

1. Role of active solar systemsA ‘ p r o g r ess i v e re ne w a b l e sce na r i o’ f o r S o u t h A f r i c a has sh o w n t he l a r ges t sh i f t t o be i n t he e le c t r i c i t y su p p l y sec t o r (see F i g u r es 67 an d 68). T o m ee t e le c t r i c i t y de ma n ds, t he c u r re n t m o de l s p r o j e c t t h a t w i t h i n t he ne x t t w o de ca des ac t i v e so la r s ys te ms c o u l d c o n t r i b u t e as m u c h t o t he p o w e r m i x as w i n d ene r g y (see F i g u r e 69). T h e r m a l ap p l i ca t i o ns a re m o s t l y m o d e l l e d as de ma n d s i d e ene r g y e f f i c i e n c y m e as u res, b u t B a n ks an d Sc hä f f l e r (2006) ha v e p r e d i c te d a stea d y, b u t s ma l l, g r o w t h i n t he so la r w a te r hea t i n g, w h i c h i n c l u des p r o cess hea t, as ene r g y su p p l y m a r k e ts (see F i g u r e 67). N e v e r t h e less,

S o u t h A f r i c a has seen re ce n t m a r k e t de ve l o p me n ts t ha t w i l l d r i v e t he i m p l e me n ta t i o n o f ac t i v e so la r ene r g y s ys te ms, e ve n w i t h i n a n u m b e r o f c o ns t ra i n t s t ha t ha ve bee n i de n t i f i e d p r i m a r i l y pe r ta i n i n g t o g o v e r na n ce issues (Seb i t os i an d P i l l a y, 2008). F o r e xa m p l e, t he e v i d e n ce o f u n c o o r d i n a te d an d at t i m es c o n f l i c t i n g ap p r oa c hes b y v a r i o u s a r ms o f g o v e r n me n t.

Figure : F inal energy supply by resource (Source: Banks and Schäffler, 2006)

Figure : Percentage contributions of renewable energies (Source: Banks and Schäffler, 2006)

Figure : P rogressive renewable scenario – meeting electricity energy demand


2.1. P V systems – market potentialT h e re a re se ve ra l i m p o r ta n t reaso ns w h y P V s ys te ms a re e x pe c te d t o p l a y a h i g h l y s i g n i f i c a n t r o l e i n S o u t h A f r i c a (Ban ks an d S c hä f f l e r, 2006):

• Ease o f use: P V m o d u l es r e p rese n t o ne o f t he eas ies t w a y s t o i m p l e me n t r e ne w a b l e ene r g y. T h e p o w e r so u r ce i t se l f i s e x t re m e l y r o b us t, re q u i r es n o m a i n te na n ce apa r t f r o m o c cas i o na l c lea n i n g, an d is o ne o f t he f e w p r o d u c ts i n t he w o r l d t ha t re g u l a r l y ca r r i es a 20-y ea r w a r r a n t y. I t i s r e la t i v e l y s i m p l e t o i ns ta l l t h o usan ds o f g r i d-i n te g ra te d s ys te ms o n d o mes t i c an d c o m m e r c i a l b u i l d i n g r o o f t o p s. P V te c h n o l o g y i s a ls o e x t r e me l y w e l l su i te d t o o f f-g r i d ap p l i c a t i o n s.

• E l e c t r i c i t y i s ge ne ra te d at p o i n t o f use: P V s ys te ms ca n be i n s ta l l e d a l m os t an y w h e re, an d ca n be rea d i l y i n t e g ra te d i n t o t he g r i d d i s t r i b u t i o n s ys te m. T h e y re p r esen t an o p p o r t u n i t y f o r i n d i v i d ua ls, c o m m e r c i a l en te r p r i ses an d o t he r pa r t i es t o ta ke ste ps a t t he i r o w n p r e m i ses t o c o n t r i b u te d i r e c t l y t o a m o r e sus ta i n a b l e ene r g y f u t u r e.

• Te c h n o l o g i es a re ra p i d l y be i n g de v e l o pe d t ha t a l l o w t he i n te g ra t i o n o f P V ce l l s o r m o d u l es i n t o d ua l-p u r p ose c o v e r i n gs an d f a b r i cs suc h as: r o o f t i l es an d r o o f i n g m e m b r a nes f o r f l a t r o o f s, d u r a b le b u i l d i n g c l a d d i n g, an d n o i se ba r r i e rs o n h i g h w a ys, a m o n gs t o t h e rs.

• T h e reso u r ce i s w e l l d i s t r i b u t e d an d i t i s re la t i v e l y eas y t o est i m a te h o w m u c h ene r g y w i l l be p r o d u ce d at pa r t i c u l a r l o ca t i o ns.

• T h e l o n g te r m m a r g i n a l c os t o f e le c t r i c i t y ge ne ra te d b y f o ss i l f u e l reso u r ces i s e x pe c te d t o i n c r ease an d t ha t t h e c os ts o f P V s ys te ms w i l l be c o me f a v o u r a b l e.

I n te r ms o f t he l a t te r, an d i n t he i n te r i m, t he r e ne w a b l e ene r g y f ee d-i n ta r i f f (REF I T) t ha t t he N a t i o na l E n e r g y R e g u l a t o r o f S o u t h A f r i c a (NE RS A, 2009) has i n t r o d u ce d is c u r re n t l y d r i v i n g t he m a r k e t p o t e n t i a l s f o r P V s ys te ms. C u r r e n t l y i t i s ap p r o v e d t ha t l a r g e sca le g r i d c o n ne c te d P V s ys te ms ( 1 M W g r o u n d/bu i l d i n g m o u n te d)≥ w i l l r e ce i v e a f ee d-i n ta r i f f o f 3.94 R/k W h. T h e p re v i o us l y su g ges te d f ee d-i n ta r i f f f o r c o n ce n t ra te d P V s ys te ms w i t h o u t st o ra ge, o f 5.48 R/k W h, has bee n re m o v e d d ue t o pe r ce i v e d h i g h ec o n o m i c c os ts (NE RS A, 2009); he re i n l a y s an o p p o r t u n i t y f o r t he resea r c h c o m m u n i t y. O t h e r i ss ues pe r ta i n i n g t o t he R E F I T a re asso c i a te d w i t h t he p u r c hase p o w e r ag ree me n ts (PP As). T h e c o nseq ue n ce has bee n m u c h i n te res t f r o m t he p r i v a te sec t o r, w h i c h a l read y sees n u me r o u s m a n u f a c t u re rs, d i s t r i b u t o r s an d re ta i l e rs o f so la r P V s ys te ms (see Ta b l e 20). I t i s en v i sa ge d t ha t t he g r o w i n g p r i v a te sec t o r w i l l p r o v i d e f u r t he r resea r c h f u n d i n g o p p o r t u n i t i es i n t he c o u n t r y, spec i f i c a l l y t o ass is t ap p l i c a t i o n s an d i m p l e me n ta t i o n s; l a r ge-sca le c o m m e r c ia l c os t c o m pa r i s o ns ha v e bee n a l read y bee n i n v es t i g a te d (Flu r i e t a l., 2008).

Table: M ajor manufacturers, distributors and retailers of solar energy components (Source: Adapted from CS I R, 2009)

Company Description of PV-related business

Te nes o lR & D , p r o d u c t des i g n, m a n u f a c t u r e o f P V m o d u l es an d spec i a l c o m p o ne n t s i n c l u d i n g i n v e r t e r s, c o n t r o l s ys te ms an d sup p o r t u n i t s. T h e c o m p a n y p r o d u c ed P V m o d u l es l o ca l l y, t he f i r s t t o m a n u f a c t u r e P V pa ne l s i n A f r i ca.

Se t S o l a rP r o v i d es t r a i n i n g, s ys te ms des i g n so l a r m o d u l e c us t o m i sa t i o n, so l a r c o m p o ne n t s, i ns ta l l a t i o ns, m a i n t e na n ce an d r e pa i r.

S o l a r W o r l d M a i n l y se l l m o d u l es w i t h a ca pac i t y o f 50 t o 80 W f o r S H S o r te le p h o ne t r a ns m i ss i o n t o w e r s.

L u m e n t e c h A n i n v e r t e r m a n u f a c t u r e r w h i c h has a r o u n d te n y ea r s o f e x pe r i e n ce i n t he so l a r i n d us t r y i n S o u t h A f r i c a.

S o l a r-Fa b r i k S pe c i a l i ses i n g r i d-c o n ne c t e d s ys te ms an d i s t ha t t he m a r k e t i s p r e d o m i n a n t l y o pe n t o sta n d-a l o n e s ys te ms.

C u r r e n t A u t o m a t i o n W h o l esa l e su p p l i e rs an d i m p o r t e r o f s ys te m c o n t r o l s an d o t he r c o m p o ne n t s.

G l o b a l W a r m i n g S t o r e W h o l esa l e su p p l i e r an d i m p o r t e r o f so l a r pa ne l s an d s ys te m c o m p o ne n t s. A s se m b l es S o l a r H o m e S ys te ms.

S o l a r G a t e w a y A f r i ca S pe c i a l i ses i n des i g n, sa les an d i ns ta l l a t i o ns o f so l a r s ys te ms an d o t he r ene r g y sa v i n g an d e f f i c i e n t p r o d u c t s.

S o l a r W o r l d A f r i ca P r o v i d e so l u t i o ns f o r so l a r s ys te ms an d p r o d u c t s sa les an d en g i n ee r i n g su p p o r t.

S o l E ne r g y A f r i ca D e s i g ns, m a n u f a c t u r e rs, i m p o r t s an d d i s t r i b u t es t h r o u g h o u t t he A f r i c a n c o n t i n e n t.

C m a c P o w e r S o l u t i o ns I ns ta l l a t i o n o f S H S an d sup p l y i n g P V e le c t r i c i t y t o h o l i da y h o m es an d sa f a r i l o d ges.

O m n i s o l a r M a i n l y de l i v e r s P V s ys te ms t o f a r m s, sc h o o l s an d c l i n i c s.

G e ne r g y C o m p a n y de v e l o ps an d sou r ces ener g y e f f i c i e n t p r o d u c t s.

E z y L i g h t A s se m b l e r an d sup p l i e r o f a l t e r na t i v e l i g h t i n g so l u t i o ns i n c l u d i n g P V, t h r o u g h L E D s ys te ms.

L o r m a r k D e s i g n an d de ve l o p m e n t so l u t i o n w h e r e so f t w a r e, e l ec t r o n i c s an d o r m e c ha n i ca l so l u t i o ns a re re q u i r e d.

B e f o r e t he i n t r o d u c t i o n o f R E F I T, i n te r na t i o na l de v e l o p m e n t age n c i es ha d bee n at t he f o r e f r o n t o f p r o v i d i n g de v e l o p m e n t f i n a n ce f o r so la r P V s (CS I R, 2009). F o r e xa m p l e, m o s t o f t he ea r l i e r ap p r oa c hes i n P V e le c t r i f i c a t i o n o f sc h o o l s an d c l i n i cs i n r u r a l pa r ts o f S o u t h A f r i c a w e re m a de p oss i b l e b y ge ne r o us f i n a n ce f r o m E U an d U S A i ns t i t u t i o ns. W h i l e t hese i n s t i t u t i o ns a re st i l l p r o v i d i n g f u n d i n g so u r ce f o r resea r c h an d de v e l o p m e n t, t he f u n d i n g m o da l i t i es ha ve c ha n ge d. T h e o r ga n i sa t i o ns p r o v i d e, a m o n gs t o t h e r t h i n gs, so f t l o a ns f o r r e ne w a b l e ene r g y p r o j e c ts, as w e l l as f a c i l i t a t i n g te c h n o l o g y t ra ns f e r (see Ta b l e 2 1).

T h e C S I R (2009) f u r t h e r o u t l i n es a n u m be r o f g o v e r n me n t de pa r t m e n ts an d re la te d i m p l e me n ta t i o n b o d i es t ha t m a y f a c i l i t a te P V-re la te d resea r c h i n S o u t h A f r i c a. F o r e xa m p l e, a t p r ese n t S A N E R I , t o be c o me S A N E D I i n t he na t i o na l D e p a r t m e n t o f E n e r g y, an d t he D e pa r t m e n t o f S c i e n ce an d Te c h n o l o g y, su p p o r t aca de m i c resea r c h pe r ta i n i n g t o P V s ys te ms t h r o u g h t he C e n t re f o r R e ne w a b l e an d S us ta i n a b l e E ne r g y S t u d i es (CRS ES), p r i m a r i l y t h r o u g h t he a l l o ca t i o n o f b u rsa r i es at v a r i o u s S o u t h A f r i c a n i n s t i t u t i o ns.

Table : M ajor international interests in solar energy in South Africa (Source: Adapted from CS I R, 2009)

I nstitution Function Examples of relevant programmes

G E F I n t e r na t i o na l c o o pe ra t i o n an d f i n a n ce ac t i o ns t o ad d r ess b i o d i v e r s i t y l o ss, c l i m a t e c ha n ge, de g r a da t i o n o f i n t e r na t i o na l w a t e r s, an d o z o ne de p l e t i o n.

P r o v i d e d g r a n t f i na n c i n g i n c o n j u n c t i o n w i t h t he U N D P an d o t h e r s f o r 23 o f f-g r i d so l a r P V p r o j e c t s i n 20 c o u n t r i es w i t h f o u r m o r e p r o j e c ts i n de v e l o p m e n t. T h ese a re p r i m a r i l y a i m e d at st i m u l a t i n g an d ach i e v i n g c o m m e r c i a l i z a t i o n o f so l a r P V s ys te ms f o r r u r a l h o useh o l ds o r “so l a r h o m e s ys te ms”. T h ese ac c o u n t f o r ab o u t U S$2 10 m i l l i o n o f G E F a l l o ca t i o n, an d ab o u t $ 1.4 b i l l i o n i n t o t a l p r o j e c t c os ts.

U N D P G l o ba l de v e l o p m e n t ne t w o r k, ad v o ca t i n g f o r c ha n ge an d c o n ne c t i n g c o u n t r i es t o k n o w l e d ge, e x pe r i e n ce an d reso u r ces t o he l p pe o p l e b u i l d a be t t e r l i f e.

C a m p a i g ns o n an i n t e r na t i o na l l e v e l f o r t he es ta b l i s h m e n t o f r e ne w a b l e ener g y so u r ces.

I S E S S u p p o r t s i t s m e m b e rs i n t he ad v a n ce m e n t o f r e ne w a b l e ener g y tec h n o l o g y, i m p l e m e n ta t i o n an d ed u ca t i o n a l l o v e r t he w o r l d.

T h e p o te n t i a l so l u t i o ns t ha t re ne w a b l e ene r g y res o u r ces can p r o v i d e i n so l v i n g t he g l o ba l ene r g y c r i s i s are c o n t i n u a l l y i n v es t i ga te d.

G T Z A n i n te r na t i o na l c o o pe r a t i o n i ns t i t u t i o n f o r sus ta i na b l e de v e l o p m e n t w i t h w o r l d w i d e o pe ra t i o ns an d sup p o r t s t he G e r m a n g o ve r n m e n t. I t a i m s t o ac h i e v e v i a b l e, f o r w a r d-l o o k i n g so l u t i o ns f o r p o l i t i c a l, ec o n o m i c, ec o l o g i c a l a n d soc i a l d e v e l o p m e n t i n a g l o ba l i se d w o r l d.

S u p p o r t s re ne w a b l e ener g y an d ene r g y e f f i c i e n c y p r o g r a m m es i n de v e l o p i n g c o u n t r i es. F u n d s v a r i o us st u d i es o n re ne w a b l e ene r g y p l a t f o r m s as w e l l as su p p o r t i n g re ne w a b l e p o l i c y i m p l e m e n t a t i o n, an d asso c i a t e d p r o g r a m m es.

R E E E P C a t a l y se t he m a r k e t f o r r e ne w a b l e ener g y an d ene r g y e f f i c i e n c y, w i t h a p r i m a r y f o c us o n e me r g i n g m a r k e t s an d de ve l o p i n g c o u n t r i es.

I n i t i a t es an d f u n ds p r o j e c t s; ta r ge te d i n te r v e n t i o ns f o r de v e l o p i n g t he m a r k e t f o r sus ta i na b l e ener g y.

E U T h e E u r o p ea n U n i o n ac ts i n a w i d e ra n ge o f p o l i c y a reas, ec o n o m i c, soc i a l, r e g u l a t o r y an d f i na n c i a l. W h e r e i t s ac t i o n is be ne f i c i a l t o t he m e m b e r sta tes an d i t s pa r t ne rs t h us a i d i n g i n t e r na t i o na l de v e l o p m e n t.

T h e 24 t hE u r o pea n P h o t o v o l t a i c S o l a r E n e r g y C o n f e r e n ce w i l l b e t he m o s t i m p o r t a n t i n t e r na t i o n a l C o n f e re n ce i n t he f i e l d o f p h o t o v o l t a i cs. I n S o u t h A f r i c a, t he E U f u n de d m a n y o f t he so l a r P V e le c t r i f i c a t i o n i n r u r a l sc h o o l s an d c l i n i cs.

2.2. P V systems – market barriersB a n k s an d S c hä f f l e r (2006) ha v e i n d i c a te d t ha t i n t he m e d i u m te r m, t he m a i n l i m i t a t i o n i s l i k e l y t o be t he ab i l i t y o f g l o ba l (and l o ca l) i n d u s t r y t o su p p l y t he m a te r i a ls an d c o m p o ne n ts re q u i r e d t o m a n u f a c t u re ce l l s o n t he sca le de ma n de d o f a g r o w i n g m a r k e t. C u r r e n t te c h n i ca l de v e l o p m e n ts a re, h o w e v e r, ac h i e v i n g a re d u c t i o n i n m a te r i a l usage. T h e C S I R (2009) desc r i b es a n u m be r o f ad d i t i o na l ba r r i e rs f o r P V m a r k e t pe ne t ra t i o n i n S o u t h A f r i c a. F o r e xa m p l e:

• T h e re q u i r e m e n ts f o r ca p i ta l an d te c h n o l o g i ca l so p h i s t i c a t i o n a re i d e n t i f i e d as c r i t i ca l ba r r i e rs, w i t h asso c ia te d h i g h f i n a n c i n g c os ts t ha t w e i g h o n t he c o m pe t i t i v e p os i t i o n o f so la r P V s ys te ms.

• T h e de ma n d f o r so la r P V s ys te ms i n S o u t h A f r i c a ha v e bee n re ga r de d as l o w o r t o o d i f f u se t o j us t i f y l a r g e-sca le l o ca l p r o d u c t i o n. A l t h o u g h p r o d u c t i o n o f P V s ys te ms is i n c r eas i n g, i t i s st i l l n o t l a r g e en o u g h t o ac h i e ve ec o n o m i es o f sca le an d ra p i d l y d r i v e d o w n p r o d u c t i o n c os ts i n S o u t h A f r i c a. W i t h l i m i t e d p r o d u c t i o n an d sa les, m a r k e t i n g an d t ra nsa c t i o n c os t a re t he re f o re h i g h an d be y o n d t he spen d i n g p o w e r o f m a n y h o useh o l ds, e ve n w i t h su bs i d i es. T h e de ma n d f o r so l a r P V s ys te ms is re la t i v e l y i n e las t i c an d l i m i t e d t o a v a r i e t y o f n i c he ap p l i c a t i o n s.

• Q u a l i t y p r o b l e ms d ue t o a l a c k o f s ta n da r d i sa t i o n an d q ua l i t y c o n t r o l ha v e re ta r d e d t he P V m a r k e t i n S o u t h A f r i c a. S ys te ms ca n be i m p r o pe r l y asse m b l e d o r i n s ta l l e d, t he re b y resu l t i n g t o de g ra d i n g, o r p o o r pe r f o r m a n ce, an d he n ce t he l o ss o f c o n f i d e n ce an d c re d i b i l i t y i n t he te c h n o l o g y an d t he d i s t r i b u t o r s. Se r v i c e an d re pa i r ca pa b i l i t i es a re l a c k i n g i n so me cases.

• A l a r ge n u m b e r o f P V p r o j e c ts ha v e f a i l e d be ca use o f l i m i t a t i o ns i n l o ca l ca pac i t y, f r o m g o v e r n me n t de pa r t m e n ts, i m p l e me n t i n g age n c i es, t o i n s ta l l a t i o n an d o pe ra t i n g c o m p a n i es. H o w e v e r, m a n y suc cess f u l cases ha v e sh o w n t ha t t h i s i ssue c o u l d be eas i l y ad d r essed i f ap p r o p r i a te m e as u res a re ta ke n ea r l y d u r i n g t he p l a n n i n g an d i m p l e me n ta t i o n p hases o f P V p r o j e c ts. A l s o i d e n t i f i e d i s t he l a c k o f i n he re n t k n o w l e d ge base i n m a r k e ts r e ga r d i n g rea l i s t i c P V o p t i o ns, o n t he l e v e l o f t he v e n d o r an d t he en d-user.

M a n y o f t hese ba r r i e rs m a y be o v e r c o m e t h r o u g h de d i c a te d resea r c h e f f o r t s. F o r e xa m p l e, Jäge r-W a l da u (2004) h i g h l i g h ts t ha t resea r c h i n i t i a t i v es a re ne cessa r y t o ad d ress t he ba r r i e rs t o t h i n f i l m

P V s ys te m i n te r ms o f p o o r i m a ge, r e la t i v e l y l o w e f f i c i e n c ies, e x pec te d l i f e t i m e, sa fe t y r e q u i r e m e n ts o f so me m a te r i a ls i n p r o d u c t i o n an d t he a va i l a b i l i t y o f m a te r i a ls, an d t he c os t o f p r o d u c t i o n eq u i p m e n t. F u r t h e r m o r e, resea r c h ce n t res m a y f a c i l i t a te s ta n da r d i sa t i o n an d q ua l i t y c o n t r o l s, w h i l s t m a n a ge me n t-o r i e n te d resea r c h m a y ad d ress te c h n o l o g y t ra ns fe r c ha l l e n ges an d p r o j e c t f a i l u r es.

2.3. CS P systems – market potentialA s w i t h P V s ys te ms, t he c o n t r i b u t i o n o f C SP s ys te ms t o t he S o u t h A f r i c a n m a r k e t i s n o t l i m i t e d b y reso u r ce a va i l a b i l i t y. F u r t h e r m o r e, t he m a te r i a l s use d t o c o ns t r u c t C SP p l a n ts a re (mos t l y) read i l y a va i l a b l e an d l a n d use is n o t a s i g n i f i c a n t c o ns t ra i n t. G i v e n t ha t t he r m a l st o ra ge is an o p t i o n i n C SP s ys te ms, t he y ca n a ls o m o r e r ead i l y m a t c h t he su p p l y/de ma n d nee ds o f t he na t i o na l g r i d (Ban ks an d S c hä f f l e r, 2006). I t i s f o r t h ese reaso ns t ha t t he R E F I T p l a ces m u c h e m p has is o n C SP s ys te ms, as f o l l o w s (NE RS A , 2009):

• Pa ra b o l i c t r o u g h w i t h o u t s t o ra ge – R 3. 14; a p r e v i o u s v e rs i o n o f R E F I T d i d i n c l u de 6 h o u rs o f s t o ra ge at R 2. 10.

• C e n t ra l re ce i v e r s w i t h 6 h o u rs o f s t o ra ge – R 2.3 1.

T h e re b y t he g o v e r n me n t a i ms t o c rea te a su f f i c i e n t m a r k e t t h a t m a y d r i v e t he C SP i n d us t r y t o w a r ds g r ea te r c o m m e r c i a l i sa t i o n an d e ve n t ua l l y d r i v e t he p r i ce o f e le c t r i c i t y f r o m C SP s ys te ms l o w en o u g h t o m a k e t he m c o m p e t i t i v e w i t h c o n v e n t i o na l ge ne ra t i o n so u r ces (Ed k i n s e t a l., 2009). C SP l ea r n i n g c u r v es a re t h o u g h t t o be an y w h e r e i n t he ra n ges o f 5-32 %, f o r pa ra b o l i c t r o u g h s ys te ms, an d 2-20 %, f o r ce n t ra l re ce i v e r s ys te ms (Wi n k l e r e t a l., 2007; W i n k l e r e t a l. 2009). A s t he te c h n o l o g y m a t u r es o n a g l o ba l sca le, c os t re d u c t i o ns a re t h o u g h t t o c o me f r o m p r o d u c t i o n c ha n ges (pro cess i n n o v a t i o ns, l ea r n i n g e f f e c ts an d sca l i n g e f f e c ts), p r o d u c t c ha n ges (inn o va t i o n, des i g n sta n da r ds an d re des i g n) an d c ha n ges i n i n p u t p r i ces (Ed k i n s e t a l., 2009). M o d e l s (Ma r q ua r d et a l., 2008) ha ve su bseq ue n t l y i n d i c a te d t ha t t he l e v e l i se d e le c t r i c i t y c os t (LE C) f r o m C SP s ys te ms m a y be c o m pe t i t i v e w i t h t he c o n v e n t i o na l c oa l s ys te ms b y 2045 an d w i t h n u c l ea r b y 2026 (see F i g u r e 70). H o w e ve r, t he u n ce r ta i n t i es o f t h e c os ts a re st i l l h i g h w

Figure : P rojections of the L E Cs from coal, nuclear and C S P systems in South Africa (Source: M arquard et al., 2008)

I n t h e l o n g-te r m, p os t-2030, t he l a r ge-sca le r o l l o u t o f C SP is e x pe c te d t o ac h i e v e c os t sa v i n gs f o r t h e S o u t h A f r i c a n e le c t r i c i t y ge ne ra t i o n sec t o r (Ed k i n s et a l., 2009). U n t i l t he n, h o w e v e r, t he ad d i t i o na l c os t t o t he e le c t r i c i t y s ys te m is est i m a te a t R 2.5 b i l l i o n f o r 20 10-20 1 5, R 8 b i l l i o n f o r 20 16-2020 an d R 23 b i l l i o n f o r 202 1-2030 (see Ta b l e 22). T h e m o de l s o f t h e l o n g-te r m m i t i g a t i o n scena r i os (SBT, 2007), w h i c h i n c o r p o r a tes te c h n o l o g y l ea r n i n g ra tes f o r C SP s ys te ms, i n d i ca te t ha t t he i n c re me n ta l i n v es t m e n t c os ts t o ac h i e v e t he r o l l o u t o f C SP s ys te ms o n t he sca le en v i s i o ne d f o r t h e sce na r i os w o u l d be R 3.9 b i l l i o n pe r y ea r f o r t he ‘S ta r t’ (2010-20 1 5) pe r i o d; r i s i n g t o R 4.4-4.9 b i l l i o n pe r y ea r f o r t h e ‘S ca le U p ’ (2016-2030) pe r i o d; an d f u r t h e r r i s i n g t o ab o u t R 1 3 b i l l i o n pe r y ea r f o r t h e ‘ R o l l o u t’ (203 1-2050) pe r i o d (Ed k i n s e t a l., 2009; W i n k l e r e t a l., 2009; H a w an d H u g h es, 2007). E d k i n s et a l. (2009) ha v e ca l c u l a te d h o w p o te n t i a l c ha n ges i n t he R E F I T m a y a f f e c t t h e an n ua l i n c re me n ta l c os t t he re o f (see F i g u r e 7 1). W i t h a re d u c t i o n i n t he ta r i f f b y 1 5 % pe r y ea r, i n l i n e w i t h t he est i m a te d l ea r n i n g ra te o f C SP s ys te ms, f r o m 20 14 o n w a r ds, a f te r t h e f i r s t C SP p l a n ts ha ve bee n c o ns t r u c te d, t he an n ua l c os t o f R E F I T w o u l d pea k a r o u n d R 30 b i l l i o n i n 2020. H o w e v e r, C SP te c h n o l o g i es m a y e x pe r i e n ce h i g he r te c h n o l o g y l ea r n i n g ra tes i f a l o ca l C SP c o m p o n e n t su p p l y i n d us t r y i s de ve l o pe d (Ed k i n s et a l., 2009).

T h i s w o u l d res u l t i n r e d u ce d u p f r o n t i n v es t me n t c os ts f o r C SP p l a n t c o ns t r u c t i o n s, w h i c h i n t u r n m a y re d u ce t he L E C (see F i g u r e 70). I f i n v es t me n t c os t re d u c t i o ns o f 5 % pe r y ea r ca n be ac h i e ve d d ue t o l o ca l p r o d u c t i o n, i n ad d i t i o n t o g l o ba l te c h n o l o g y l ea r n i n g f o r C SP s ys te ms, t he n i n c re me n ta l i n v es t m e n t c os ts f o r t he l a r g e-sca le r o l l o u t o f C SP is est i m a te d (Ed k i ns et a l., 2009) t o be m u c h l o w e r (see Ta b l e 22).

Table : S cenarios for large-scale rollout of C S P in South Africa

Start Scale-up R ollout

2010-2015 2016-2020 2021-2030 2031-2050

C O 2-eq e m i ss i o ns a v o i d e d 20 M t

(4 M t/y r)

1 40 M t

(28 M t/y r)

370 M t

(38 M t/y r)

3270 M t

(165 M t/y r)

S ha re o f e le c t r i c i t y sec t o r

(insta l l e d ge ne ra t i n g ca pac i t y)4 %

(2 G W) b y 20 1 5

1 3 %

(7 G W) b y 2020

27 %

(24 G W) b y 2030

55 %

(100 G W) b y 2050

I n c r e m e n t a l c os t t o e l ec t r i c i t y ge ne ra t i o n s ys te m a 2.5

(0.4/yr)

8

(1.6/yr)

23

(2.3/yr)

-2

(-0. 1. y r)

I n c r e m e n t a l i n v es t m e n t c os t o f C SP r o l l o u t a

W i t h tec h n o l o g y l ea r n i n g b 23.5

(3.9/yr)

24.6

(4.9/yr)

44

(4.4/yr)

266

(13/yr)

W i t h tec h n o l o g y l ea r n i n g b an d l o ca l p r o d u c t i o n c

22.9

(3.8/yr)

1 9.4

(3.9/yr)

20

(2/yr)

87

(4.3/yr)

a B i l l i o n R a n ds i n 2008b L e a r n i n g ra t i o i s 1 5 % an d 20 % r e d u c t i o n pe r d o u b l i n g o f de p l o y m e n t f o r pa r a b o l i c t r o u g h an d ce n t r a l re ce i v e r s res pe c t i v e l y.C L o c a l p r o d u c t i o n o f C SP c o m p o ne n t s i s assu m e d t o r e d u ce C SP i n v es t m e n t c os t s a t a r a te o f 5 % pe r y ear.

Figure : Estimated annual costs of R E F I T, reduced by 5%, 10% and 15% after the first C S P plants are built in 2014, in support of the large-scale rollout of C S P

2.4. CS P systems – market barriersA w o r k s h o p f a c i l i t a te d b y t he E ne r g y R esea r c h C e n t r e (ER C) h i g h l i g h te d t ha t a so l a r i n d u s t r y de ve l o p m e n t p r o g r a m m e c o u l d l ea d t o l a r g e-sca le e m p l o y m e n t c rea t i o n an d p oss i b l e f o r e i g n ea r n i n g s t h r o u g h t he e x p o r t o f t he te c h n o l o g y, espec i a l l y i f S o u t h A f r i c a w e r e t o be c o m e a m a r k e t l ea de r i n t he l ess de v e l o pe d ce n t ra l re ce i v e r an d l i n ea r F r esne l te c h n o l o g i es (Ed k i ns e t a l., 2009). I t w a s f u r t h e r n o te d t ha t t h e w e l l-es ta b l i s he d au t o m o t i v e m a n u f a c t u r i n g i n d us t r y c o u l d p oss i b l y e v o l v e t o su p p l y t he C SP i n d us t r y; i f 5.9 e m p l o y m e n t o p p o r t u n i t i es a re e x pe c te d f o r eac h M W o f C SP ge ne ra t i o n ca pac i t y c o ns t r u c te d t he n t he l a r ge-sca le r o l l o u t o f C SP m a y resu l t i n c rea t i n g o v e r 600,000 e m p l o y e d p os i t i o n s. H o w e v e r, t he sa me w o r k s h o p ra i sed a n u m b e r o f i ssues f a c i n g t he l a r ge-sca le r o l l o u t o f C SP i n S o u t h A f r i c a. T h e l a r ges t ba r r i e r i s f i n a n c i a l su p p o r t, w i t h t he o t he rs g r o u pe d i n t o te c h n o l o g i c a l (inn o va te), i n f r as t r u c t u re (ope ra te), i n d us t r y-r e la te d (manu f a c t u re) an d l e ga l/reg u l a t o r y (reg u l a te) iss ues (see Ta b l e 23).

Table : M ain barriers facing the large-scale rollout of C S P in South Africa (Source: Adapted from Edkins et al., 2009)

Start2010-2015

Scale-up2016-2020

Rollout2021-2050

I n n o v a t e I m p o r t tec h n o l o g y

T h e r m a l st o ra ge tec h n o l o g y

E s k o m c o o pe ra t i o n

S o u t h A f r i ca n spe c i f i c tec h n o l o g y

W a t er-sa v i n g tec h n o l o g y

A d o p t / m a n u f a c t u r e R i s k y i n v es t me n t:

‘ Tes t P l a n t’ b r a n d i n g – n o m a r k e t o u t l o o k

L a c k i n g s k i l l s f o r l o c a l c o n t e n t

O p e r a te / m a i n t a i n I n i t i a l g r i d e x pa ns i o n M a ss i v e g r i d e x pa ns i o n

L a c k i n g s k i l l s

G r i d-w i d e st o ra ge

W a t er-st r ess

R e g u l a te R E F I T u n tes te d R E F I T e x p i r y u n k n o w n S A PP da y-ahead m a r k e t

F i n a n ce V e n t u r e cap i t a l an d g r a n t s f r o m c l i m a te c han ge f u n ds, e.g. W o r l d B a n k an d o t he r C l ea n Te c h n o l o g y F u n ds

I n v es t m e n t f a c i l i t a t i o n; N A M A c r e d i t i n g f r o m c l i m a t e c ha n ge f u n d s an d l o a ns

E q u i t y, m e z z an i ne, de b t, i n s u ra n ce an d ca r b o n-based

S t a k e h o l de r i n t e r es ts R E F I T es ta b l i s he d G r o w i n g so l a r i n d us t r y de v e l o p m e n t p r o g r a m m e

F u t u r e e m p l o y m e n t an d e x p o r t s

S t a k e h o l de r c o n c e r ns R E F I T u n tes te d E s k o m as e l ec t r i c i t y d i s t r i b u t o r E n v i r o n m e n t a l I m p a c t A s sess me n ts – w a t e r

So m e o f t hese ba r r i e rs ca n be ad d r essed b y c o n ce r te d r esea r c h e f f o r ts. F o r e xa m p l e (Ed k i ns et a l., 2009):

• T o sta r t l a r ge-sca le r o l l o u t o f C SP, S o u t h A f r i c a w o u l d ha v e t o i n v es t i n i m p o r t i n g t he re q u i r e d te c h n o l o g y, i n pa r t i c u l a r pa ra b o l i c t r o u g h te c h n o l o g i es: Te c h n o l o g y t ra ns f e r i ss ues an d c ha l l e n ges nee d t o be i n v es t i ga te d.

• T h e r m a l s t o ra ge te c h n o l o g y, su c h as m o te l sa l t s t o ra ge, w o u l d a ls o ha v e t o be ac q u i r e d, an d i m p o r t i n g suc h te c h n o l o g y m a y p r o v e c os t l y : N e w st o ra ge te c h n o l o g i es nee d t o be resea r c he d an d de v e l o pe d.

• S m a l l e r-sca le ap p l i c a t i o n s o f C SP f o r o f f-g r i d c o m m u n i t i es o r r o o f t o p s a re r e q u i r e d: Feas i b i l i t y s t u d i es an d de m o ns t ra t i o n f a c i l i t i es nee d t o be de ve l o pe d.

• E x i s t i n g h y b r i d s ys te ms a re n o t ap p r o p r i a te f o r S o u t h A f r i c a, s i n ce t hese s ys te ms re l y p r i m a r i l y o n na t u r a l gas: C oa l w o u l d a ls o ha ve t o be i n v es t i g a te d f o r c o u n t r y-spec i f i c C SP des i g ns as a su i ta b le ba c k u p f u e l.

• T h e a va i l a b i l i t y o f w a te r reso u r ces: C h a n ges i n a va i l a b i l i t y d ue t o c l i m a te c ha n ge nee ds t o be i n v es t i ga te d as w e l l as n o v e l w a te r res o u r ce m a na ge me n t p r a c t i ces; e x i s t i n g d r y c o o l i n g te c h n o l o g y e x pe r t i se nee d t o be e x pa n de d i n t he c o u n t r y.

• I n f r as t r u c t u r e ba r r i e r s: I n te g r a te d p l a n n i n g st u d i es nee d t o be o n g o i n g, an d espec i a l l y pe r ta i n i n g t o t ra ns m i ss i o n an d st o ra ge o n t he na t i o na l g r i d, e.g. t h r o u g h t he p r o m o t i o n o f e le c t r i c v e h i c l es o r m o r e p u m p-st o ra ge sc he mes.

• G o v e r na n ce ba r r i e rs: R e g u l a t o r y ba r r i e r s, su c h as t he E n v i r o n me n ta l I m p a c t A s sess me n t p r o cess, nee d t o be i n v es t i g a te d, as w e l l as de v e l o p i n g t he N S I t o e x pa n d t he e x i s t i n g m a n u f a c t u r i n g sec t o r t o acc o m m o da te a C SP i n d us t r y i n S o u t h A f r i c a.

I n a l l cases f i n a n c i a l su p p o r t f o r t hese resea r c h e f f o r ts a re ne cessa r y f o r C SP de v e l o pe rs t o p r e pa re f eas i b i l i t y st u d i es. F o r t he S ta r t p hase o f l a r ge-sca le C SP r o l l o u t i n S o u t h A f r i c a (2010-20 15) f i n a n c i n g c o u l d c o m e f r o m c o m m e r c i a l i n v es t o rs an d de v e l o p m e n t f i n a n ce rs, su c h as t he I n d us t r i a l D e v e l o p me n t C o r p o r a t i o n (Ma ia, 2009). H o w e ve r, t he c u r re n t g l o ba l ec o n o m i c c l i m a te p r esen ts d i f f i c u l t i es f o r C SP de v e l o pe rs t o access f i n a n ce, e ve n w i t h t he R E F I T i n p l a ce (Ed k i ns e t a l., 2009), an d p u b l i c f i n a n c i n g m e c h a n i s ms a re t he re f o r e (st i l l) re q u i r e d. T h ese w o u l d i n c l u de R & D su p p o r t an d g r a n ts f r o m c l i m a t e c ha n ge f u n ds, suc h as t he C l ea n Te c h n o l o g y F u n d o f t he W o r l d B a n k (2009), an d t he C l ea n Te c h n o l o g y F u n d I n v es t m e n t P l a n o f t h e G o v e r n me n t o f S o u t h A f r i c a (2009).

2.5. Solar chimneyT h e so la r c h i m n e y te c h n o l o g y has bee n t he f o c u s o f s i g n i f i c a n t resea r c h e f f o r t s i n S o u t h A f r i c a (Flu r i e t a l., 2008). H o w e ve r, as is re p o r te d i n t he i n t e r na t i o na l l i t e ra t u r e (see sec t i o n 3. 1.5), t he i n v es t m e n t c os ts a re h i g h l y

SWH market scenario

0

10 000 000

20 000 000

30 000 000

40 000 000

50 000 000

60 000 000

1995

1997

1999

2001

2003

2005

2007

2009

2011

2013

2015

2017

2019

2021

2023

2025

m²

Total population

A.Total collector area installed,high growth

Middle

B Total collector area installed lower growth

SWH equival of el geyser escalated 1,03/a

SWH equival of el geyser escalated 1,08/a

u n ce r ta i n, an d l a r g e-sca le de m o ns t ra t i o n i s r e q u i r e d o f t h e te c h n o l o g y t o de te r m i ne t he t r u e m a r k e t p o te n t i a l. S u bse q ue n t l y, a t p r ese n t t h e re i s l i t t l e S o u t h A f r i c a n su p p o r t, i n t he p u b l i c an d p r i v a te sec t o r s, f o r t hese s ys te ms.

3. Thermal heating and cooling applications

3.1. General potential and barriersT h e l as t ha l f-de ca de has seen m a n y i n v es t i g a t i o n s o f t he p o te n t i a l m a r k e t f o r so l a r w a te r hea t i n g (Ho l m, 2005). T h ese st u d ies a l l h i g h l i g h t t he s i g n i f i c a n t p o te n t i a l o f so la r w a te r hea t i n g i n S o u t h A f r i c a, w i t h a n u m b e r o f sce na r i os t ha t ha v e bee n en v i sa ge d (see F i g u r e 72).

Figure : Scenario of maximu m S W H m arket penetration in South Africa (Source: Banks and Schäffler, 2006)

H o w e ve r, t he m a r k e t pe ne t ra t i o n has bee n re la t i v e l y p o o r; w i t h a c u r r e n t es t i m a te d i n s ta l l e d ca pac i t y o f j us t u n de r 1 G W t h, o r a r o u n d 3.5 k W t h/1000 i n ha b i ta n ts f o r g l a ze d s ys te ms an d 9 k W t h/100 i n ha b i t a n ts f o r u n g l a ze d s ys te ms, S o u t h A f r i c a d oes n o t f a l l i n t he u p pe r ca te g o r i es o f c o u n t r i es (We iss et a l., 2009). T h i s i n d i c a tes sc o pe f o r m u c h m o r e de ve l o p m e n t, a l b e i t i n t he f a ce o f a n u m b e r o f c ha l l e n ges, as desc r i be d i n t he base l i n e st u d y o f t he na t i o na l p r o j e c t, t ha t nee d t o be ad d ressed t h r o u g h resea r c h:

• A w a re ness, p r o m o t i o n an d i n f o r m a t i o n: I n n o v a t i v e w a y s a re r e q u i r e d t o de m o ns t ra te an d p r o v e t he be ne f i t s o f t h ese te c h n o l o g i c a l s ys te ms t o so c i e t y a t l a r g e.

• C o s t an d c o m pe t i t i v e ness: I n n o v a t i o n i s re q u i r e d i n t he m a n u f a c t u r i n g su p p l y c ha i n t o d r i v e d o w n c os ts.

• F i na n c i a l: N e w m o d e l s a re re q u i r e d t o su p p o r t t he i n t r o d u c t i o n o f t he te c h n o l o g i es ac r oss a l l m a r k e t seg me n ts.

• Te c h n i c a l: R & D f a c i l i t i es a re r e q u i r e d t o su p p o r t s ta n da r ds c o m p l i a n ce.

• C a pa c i t y an d q ua l i t y assu ra n ce: Q u a l i t y m a na ge me n t an d m a i n te na n ce st r u c t u res a re re q u i r e d t o su p p o r t t he S W H i n d us t r y.

• Po l i c y an d re g u l a t i o n.

I n te r ms o f t he l a t te r, t h e D e pa r t m e n t o f E n e r g y (DoE, 2009) re ce n t l y re leased a d r a f t st ra te g i c f r a m e w o r k an d i m p l e me n ta t i o n p l a n t ha t a i m s t o ac h ie ve acce le ra te d de l i v e r y o f so la r w a te r hea t i n g i n S o u t h A f r i c a t h r o u g h (Yaw, 2009):

• A m a r k e t f o c u se d an d nee ds d r i v e n st ra te g y t o ensu re m a x i m u m ta ke-u p an d de p l o y m e n t o f so l a r w a te r hea t i n g i n t he c o u n t r y.

• Seg me n ta t i o n o f t he t o ta l r es i de n t i a l m a r k e t i n t o d i s c re te sec t o r s an d ‘ needs c l us te rs ’, p l us a c o m me r c i a l/i n d us t r i a l m a r k e t.

• A ‘ f i t f o r p u r p o se’ l i m i t e d ra n ge o f p r o v e n te c h n o l o g y, s ys te ms an d su p p l y a r ra n ge me n ts t o m ee t t he p r e c i se nee ds o f eac h m a r k e t sec t o r.

• B u s i n ess m o d e l/s an d f u n d i n g m e t h o ds t o ensu re u n i v e rsa l a ccess t o a l l h o m es i n S o u t h A f r i c a o n a s l i d i n g sca le bas is w i t h u p pe r i n c o m e h o use h o l d e rs c o n t r i b u t i n g s i g n i f i c a n t l y t o t he c os t t h r o u g h t o i n d i g e n t h o mes re ce i v i n g a “ v i r t ua l f r ee” S W H s ys te m. T h i s i s v i e w e d as a ‘ p u b l i c access’ t o essen t i a l se r v i c e an d m a r k e t c r ea t i o n p r o g r a m m e, s i n ce l o w e r i n c o m e h o use h o l d s (>75 % o f t o ta l S A h o use h o l d s) a re c u r re n t l y u n-se r ve d.

• E na b l i n g t he p r o g r a m m e t h r o u g h i n s t i t u t i o na l de l i v e r y m o de l s t o ens u re ec o n o m i es o f sca le, c l ea r l ea de rs h i p an d acc o u n t a b i l i t y f o r resu l ts.

• I n s t i t u t i o na l de l i v e r y m o d e l s t ha t i n te g ra te an d l e ve ra ge a ra n ge o f f i n a n c i a l, o r ga n i sa t i o na l, p u b l i c an d p r i v a te sec t o r ac t i v i t i es t o c rea te a c o-o r d i n a te d an d f o c u se d de l i v e r y o pe ra t i o n. D e p l o y m e n t o f a ra n ge o f i n c o me st rea ms, t ra i n i n g an d ne w b us i n ess i n ce n t i v es, s k i l l s t ra i n i n g ce n t res, S A B S, ta x i n ce n t i v es, p r i v a te sec t o r su p p l y an d i ns ta l l a t i o n, a m o n gs t o t h e rs.

• R e-en g i n ee re d su p p l y c ha i ns, d r i v i n g c os ts d o w n an d e f f i c i e n c ies u p a t e ve r y sta ge. A ne w, sta n d a l o ne an d c o m p e t i t i v e l y r es o u r ce d na t i o na l S W H p r o g r a m m e o pe ra t i n g o n a m a r k e t sec t o r ta r ge te d ‘ r o l l o u t’ bas is s i m i l a r t o e le c t r i f i ca t i o n, t o re m o v e de l i v e r y c o ns t ra i n ts.

• D e p l o y i n g l a r g e v o l u m e b u y i n g o f spec i f i e d S W H S ys te ms a t d i s c o u n t an d st r i n ge n t c o m p e t i t i v e ten de r i n g an d c o n t r a c t ua l a r ra n ge me n ts w i t h p r i v a te sec t o r i n s ta l l a t i o n su b-c o n t r a c t o rs.

• C a pa c i t y b u i l d i n g an d l i v e l i h o o d/j o b c rea t i o n w i t h de d i ca te d s k i l l s t ra i n i n g an d ac c re d i ta t i o n.

• E na b l i n g a sus ta i n a b l e S o u t h A f r i c a n l o w c os t, h i g h v o l u m e, S W H s ys te m m a n u f a c t u r i n g an d i ns ta l l a t i o n i n d us t r y w i t h i n a de f i n e d t i m e pe r i o d a f te r t he c o m m e n ce me n t o f t h e na t i o na l p r o g r a m m e.

T h i s so l u t i o n des i g n, as c o m pa re d t o ba r r i e r/pr o b l e m so l v i n g, ap p r oa c h is en v i sa ge d t o ad d r ess t he ab o v e me n t i o ne d c ha l l e n ges an d i n i t i a te a se l f-d r i v e n m a r k e t i n a sh o r t t i m e f r a m e; t he o v e r a l l ta r ge t i s t he de l i v e r y o f 1 m i l l i o n so la r w a te r hea te rs b y 20 14 an d 5 m i l l i o n b y 2020 (see Ta b les 24 an d 25).

Table : Composite m arket-based targets for solar water heating in South Africa (Source: Afrane Okese, 2009)

Residential market targets By 2014 By 2020 Potential %

U p p e r i n c o m e ge yse r r e p l a ce m e n t 2 10 000 560 000 1 200 000 47

M i d/ l o w i n c o m e ge yse r re p l a ce me n t 450 000 1 750 000 3 000 000 58

N o n ge yse r de l i v e r y 340 000 2 690 000 6 600 000 4 1

1 000 000 5 000 000 1 0 800 000 46

Table : S W H impact goals after the delivery of 1 million units ( Source: Afrane Okese, 2009)

Residential market targets

Reducing electricity demand (M W)

Universal access

Offset rising electricity cost

Accelerated service delivery

Renewable energy targets

(G Wh /annum)

Climate change (‘000 tons)

U p p e r i n c o m e ge yse r s

1 30C o m p l e te l y eq u i t a b l e ac r oss t he m a r k e t s. P l us f r ees g r i d capa c i t y

< 60 % o f w a t e r hea t i n g c os ts

252 6 1 2

M i d/ l o w i n c o m e ge yse r s

279< 70 % o f w a t e r hea t i n g c os ts

M a j o r i m p a c t 540 1 248

N o n ge yse r de l i v e r y 2 1 1< 80 % o f w a t e r hea t i n g c os ts

M a j o r i m p a c t 408 842

620 1 200 2703

T h e ad d i t i o na l g oa ls o f t he na t i o na l st ra te g i c f r a m e w o r k an d i m p l e me n ta t i o n p l a n i n c l u de:

• 1 ,49 1,000 t o ns o v e r t he 5 y ea rs t h r o u g h, p r i m a r i l y, t he C D M ;

• N a t i o na l c os t be ne f i t o u t c o mes R 1 2.8 b i l l i o n (exc l u d i n g ne w b u i l d);

• L o c a l m a n u f a c t u r i n g ca pac i t y de ve l o p me n t, l ea d i n g t o e x p o r t; an d

Total Energy

Non-specified (Other)3.55%

Residential18.58%

Commerce and Public Services7.35%

Agriculture2.67%

Transport Sector26.51%

Industry Sector41.34%

Electricity

Non-specified (Other)12.26%

Residential17.24%

Commerce and Public Services12.64%

Agriculture2.57%

Transport Sector2.59%

Industry Sector52.70%

Total energy in Industrial sector

Textile and Leather0.17%

Wood and Wood Products

0.10% Construction

1.49%

Paper Pulp and Print

0.78%

Food and Tobacco0.34%

Mining and Quarrying18.46%

Non-specified (Industry)25.28%

Iron and Steel27.56%

Chemical and Petrochemical

12.79%

Non-Ferrous Metals6.05%

Non-Metallic Minerals6.75%

Transport Equipment

0.03%

Machinery0.21% Electricity

Machinery0.04%

Transport Equipment

0.08%

Non-Metallic Minerals2.30%

Non-Ferrous Metals16.49% Chemical and

Petrochemical8.92%

Iron and Steel18.88%

Non-specified (Industry)22.42%

Mining and Quarrying27.88%

Food and Tobacco0.67% Paper Pulp

and Print1.55%

Construction0.05%

Wood and Wood Products

0.26%

Textile and Leather0.46%

• E m p l o y m e n t c rea t i o n – te m p o r a r y an d pe r m a ne n t – t h r o u g h S H W se r v i c e, s k i l l s an d l i v e l i h o o d l e ga c i es i n p o o r c o m m u n i t i es.

T h e g oa l a f te r t he r o l l o u t o f 5 m i l l i o n S W H u n i ts i s t o re d u ce e le c t r i c i t y de ma n d b y o v e r 3 G W. S i m i l a r l y, s i g n i f i c a n t e le c t r i c i t y re d u c t i o n s a re p oss i b l e t h r o u g h space, an d p r o cess, hea t i n g an d c o o l i n g ap p l i ca t i o ns (Roos, 2009). H o w e ve r, i n v es t i g a t i o n s ha ve o n l y t o u c he d o n t hese m a r k e t p o te n t i a ls an d ba r r i e r s (Ban ks an d Sc hä f f l e r, 2006), an d t he re a re st i l l m u c h u n ce r ta i n t i es.

3.2. Potential for industrial applicationsA s n o te d i n t he base l i n e re p o r t o f t he na t i o na l p r o j e c t, h i g h te m pe r a t u re ap p l i c a t i o n s ha v e bee n c o ns i d e re d i n t he S o u t h A f r i c a n c o n te x t, espec i a l l y w i t h i n t he hea v y i n d us t r i a l base o f t he c o u n t r y t o i m p r o v e ene r g y (and ca r b o n) e f f i c i e n c i es, an d f o r spec i f i c ap p l i c a t i o n s suc h as t he gas i f i c a t i o n o f c oa l (Roos, 2009).

V a n n o n i e t a l. (2008) ha ve c o n c l u de d t ha t so la r t he r m a l c o u l d p r o v i d e t he i n d u s t r i a l sec t o r w i t h 3 t o 4 % o f i t s hea t de ma n d i n E u r o p e (see Ta b l e 1 9). G i v e n t ha t S o u t h A f r i c a has a be t te r so la r reso u r ce t ha n E u r o pe an d t he i n d us t r i es desc r i b e d e x i s t i n S o u t h A f r i c a, t he pe ne t ra t i o n o f so la r p r o cess hea t te c h n o l o g i es i n t o t hese i n d u s t r i es i n S o u t h A f r i c a ca n be e x pec te d t o be c o m p a r a b le o r be t te r w i t h su i ta b le su p p o r t i n i t i a t i v es.

N o w i n S o u t h A f r i c a, t he f o o d, w i n e an d be v e ra ge, pa per, te x t i l e an d au t o m o t i v e i n d us t r i es a l l e x i s t. T h e y ca n be ta r ge te d f o r so la r p r o cess hea t i n t he sa me w a y as E u r o pe. U n f o r t u na te l y, t h o u g h, t hese sec t o r s f o r m a m u c h s ma l l e r f r a c t i o n o f ene r g y de ma n d i n S o u t h A f r i c a t ha n i n E u r o p e. F i g u r es 73 an d 74 sh o w t ha t t h e i n d us t r i a l sec t o r c o m p r i ses 4 1 % o f ene r g y use, s i m i l a r t o t he 30 % o f E u r o p e. W i t h i n t he i n d u s t r i a l sec t o r, h o w e v e r, m i n i n g, i r o n an d stee l, n o n-f e r r o us m e ta l s an d n o n-m e ta l m i n e ra l s t o ge t he r c o ns u me 59 % o f ene r g y an d 66 % o f e le c t r i c i t y c o ns u m e d i n t he i n d us t r i a l sec t o r.

Figure : Total energy and electricity consumption in South Africa per sector in 2005

Figure: Total energy and electricity consumption in the industrial sector in South Africa per sector in 2005

H e re t he g r ea tes t c o n t r i b u t i o n t ha t c o u l d be m a de b y so la r i n d u s t r i a l p r o cess hea t w o u l d p r o ba b l y be p r o v i d e d b y pa ra b o l i c t r o u g hs: f i r s t l y d r i v i n g d o u b l e e f f e c t abso r p t i o n c h i l l e rs f o r m i n i n g v e n t i l a t i o n, an d sec o n d l y p r o v i d i n g p r o cess stea m i n t he c he m i ca l an d pe t r o c he m i ca l i n d u s t r i es, an d o t he rs. A i r c o n d i t i o n i n g o f c o m m e r c i a l b u i l d i n gs m a y re q u i r e s i n g l e-e f f e c t abs o r p t i o n c h i l l e rs w i t h sta t i o na r y c o l l e c t o r s as t he r o o f m a y n o t be i dea l f o r pa ra b o l i c t r o u g hs. A s ma l l l i n ea r F r esne l w o u l d be i dea l, h o w e v e r, d r i v i n g a d o u b l e e f f e c t abso r p t i o n c h i l l e r. T h e use o f so l a r c o l l e c t o r s t o d r i v e l a r ge-sca le t he r m a l desa l i n a t i o n p l a n ts (such as m u l t i-e f f e c t desa l i na t i o n o r m u l t i-sta ge f l as h) a l l o w s a so l u t i o n t o b o t h m i n e ac i d d ra i na ge an d f r esh w a te r a t m i n es.

I m p o r t a n t he re i s t he rea l i sa t i o n t ha t t he m a n u f a c t u r i n g an d i ns ta l l i n g o f c o l l e c t o r s f o r so la r i n d u s t r i a l p r o cess hea t i s an i n d us t r y i n i t s o w n r i g h t, m e e t i n g g o v e r n me n t i m p e ra t i v es o f l a b o u r-i n te ns i v e e m p l o y m e n t, c l i m a te c ha n ge m i t i g a t i o n an d ene r g y sec u r i t y.

4. Assessing the potential for active solar systemsT h e rea l i se t he t r u e p o t e n t i a l f o r ac t i v e so la r s ys te ms t o c o n t r i b u te t o t he ene r g y m i x o f S o u t h A f r i c a w o u l d re q u i r e de ta i l e d assess me n ts o f t h e so la r reso u r ce o f t h e c o u n t r y. H i g h so la r i r r a d i a t i o n l e ve ls a re t he m a i n c r i t e r i a t o de te r m i n e i f spec i f i c s i tes a re su i ta b le. I n i t i a l sc o p i n g st u d i es use a va i l a b le so la r m a ps de r i v e d f r o m e i t h e r m easu r e d da ta an d/or sa te l l i t e de r i v e d da ta. A f t e r a su i ta b l e s i te has bee n i de n t i f i e d, i n de pe n de n t, o n-s i te m eas u r e me n ts a re re q u i r e d t o v e r i f y t h e a va i l a b l e da ta an d o b t a i n an acc u r a te r e c o r d o f a t l eas t o ne y ea r o f re c o r de d so la r i ns u l a t i o n. T h e re c o r de d so l a r da ta a re c o r r e l a te d t o sa te l l i t e da ta o f t he sa me pe r i o d. T h e h i s t o r i c sa te l l i t e da ta se t f o r a t l eas t se ve n y ea rs, t o ge t he r w i t h t he m eas u r e d da ta, i s t he n use d t o de te r m i n e t he so la r reso u r ce o f a spec i f i c s i te.

M e as u r e me n t eq u i p m e n t n o r m a l l y re ma i n s o n s i te i n o r de r t o f u r t h e r u p da te t he sa te l l i t e de r i v e d da ta an d t o m o n i t o r t h e pe r f o r m a n ce o f a so la r ene r g y s ys te m. Sa te l l i t e de r i v e d so la r da ta a re t y p i c a l l y o b ta i n e d f r o m t he D L R (Ger ma n A e r o s pace A g e n c y) o r S o D a (Fren c h A g e n c y).

F o r c o n ce n t ra te d so la r t h e r m a l s ys te ms t he m eas u re me n t eq u i p m e n t m u s t de te r m i n e t he D N I (D i re c t N o r m a l I r r a d ia n ce) c o m p o n e n t o f t he so la r i r r a d ia n ce. L o w c os t s ys te ms t y p i c a l l y e m p l o y a r o ta t i n g sha d o w ba n d s ys te m i n w h i c h t he D N I an d o t he r c o m p o ne n ts a re ca l c u l a te d. H i g h c os t s ys te ms n o r m a l l y d i r e c t l y m eas u res t he D N I w i t h a P y r he l i o m e te r m o u n te d o n t he so la r t ra c k er. T y p i c a l l y a se t o f P y r a n o me te rs m eas u res t he G H I (Gl o ba l H o r i z o n ta l I r r a d i a n ce) an d d i f f u se d i r r a d i a n ce t o ge t h e r w i t h a sha d o w ba l l. T h e t y p i c a l c os t o f su c h a s ys te m is R 250,000. F o r p h o t o-e le c t r i ca l s ys te ms t he G H I i s su f f i c i e n t an d t he L T I (Lat i t u de T i l t I r r a d ia n ce) is t y p i c a l l y ca l c u l a te d f r o m t h i s pa ra me ter.

S o u t h A f r i c a c u r r e n t l y l a c k s a de d i ca te d i ns t i t u t i o n t ha t ca n u n de r ta ke su c h assess me n ts an d c o n ce n t ra te o n:

• C a l i b r a t i n g m eas u re me n t i ns t r u m e n ta t i o n, an d p r o v i d i n g ac cess t o su p p l i e rs an d re la te d c os ts;

• U n de r ta k i n g re m o te da ta ca p t u r i n g; an d

• O b ta i n i n g sa te l l i t e da ta (images) an d p r o d u c i n g sa te l l i t e de r i v e d da ta (mode ls), i n c l u d i n g ca l i b r a t i n g da ta an d p r o v i d i n g access t o se r v i c e p r o v i d es an d re la te d c os ts.

4. ST R AT E G I C A NALYS I S FO R R E S E A R C H I N SOUT H A F R I C A

1. South African National System of I nnovationI n t h i s sec t i o n a st ra te g i c ana l ys is o f t he d i f f e re n t so la r te c h n o l o g i es desc r i b e d i n sec t i o n 2, an d spec i f i c a l l y t h ose t ha t a re v i e w e d as i n t e r n a t i o na l l y c o m pe t i t i v e (sect i o n 3) an d w i t h t he g r ea tes t S o u t h A f r i c a n m a r k e t p o te n t i a l (sec t i o n 4), is c o n d u c te d w i t h i n t he S o u t h A f r i c a n na t i o na l s ys te m o f i n n o v a t i o n (NS I) f r a m e w o r k. T h e p u r p o se o f t he ana l ys is i s t o j u d ge t he ad v a n ta ges an d d i sa d va n ta ges o f t h e v a r i o us so la r ene r g y s ys te ms t o w a r ds at ta i n m e n t o f l o n g-te r m g oa l s an d o b j e c t i v es, as o u t l i n e d i n sec t i o n 1 , b y h i g h l i g h t i n g k e y st ra te g i c r esea r c h f o c us a reas as w e l l as t he re q u i r e d i n t e r v e n t i o n s b y v a r i o us r o l e p l a y e rs t o ena b l e su c h resea r c h.

A N S I i s t ha t se t o f d i s t i n c t i ns t i t u t i o n s w h i c h, j o i n t l y an d i n d i v i d ua l l y, c o n t r i b u t e t o t he de ve l o p me n t an d d i f f u s i o n o f ne w te c h n o l o g i es an d w h i c h p r o v i d es t he f r a m e w o r k w i t h i n w h i c h g o v e r n me n ts f o r m an d i m p l e me n t p o l i c i es t o i n f l u e n ce t he i n n o v a t i o n p r o cess (Me t ca l f e, 1 9 95). T h i s ne t w o r k o f p u b l i c an d p r i v a te sec t o r s ac t i v i t i es an d i n t e ra c t i o ns i n i t i a te, i m p o r t, m o d i f y an d d i f f u se ne w te c h n o l o g i es (Free ma n, 1 987). T h e m a i n sta ke h o l d e rs i n a N S I a re t y p i ca l l y g o v e r n me n t, i n d u s t r y an d resea r c h i ns t i t u t i o n s o f a spec i f i c c o u n t r y. T h e c l ose c o l l a b o r a t i o n an d re la t i o n s h i ps be t w ee n t he sta ke h o l d e rs a re o f g rea t i m p o r ta n ce f o r an e f f i c i e n t N S I (see F i g u r e 75).

Figure : The government – research institutions – industry relationship in the N S I

D e pe n d i n g o n w h i c h c ha ra c te r i s t i c s o f a N S I a re t o be e m p has ised, a spec i f i c i n n o v a t i o n m o d e l i s use d, f o r e xa m p l e t he T r i p l e-H e l i x m o de l used i n S w e de n (Etz k o w i t z an d L e y d esd o r f f, 2000), w h e r e t he e m p has is i s st r o n g l y o n resea r c h. T h e r o l e o f g o v e r n m e n t i n a N S I i s t o de v e l o p ap p r o p r i a te i n n o v a t i o n p o l i c i es an d t o p r o v i d e f u t u re d i r e c t i o n t o t he i m p l e me n ta t i o n o f t hese p o l i c i es. T h e v a r i o us resea r c h i ns t i t u t i o ns (pub l i c an d p r i v a te) ha v e t he tas k t o c rea te an d t ra ns fe r ne w k n o w l e d ge an d te c h n o l o g y w i t h i n t he N S I, w h i l s t i n d us t r y ’s m a i n tas k i s t o c o m m e r c ia l i se t he ne w l y c r ea te d k n o w l e d ge an d te c h n o l o g y w i t h i n ap p r o p r i a te m a r k e ts i n o r de r t o c rea te w ea l t h.

T h e e f f i c i e n c y o f a N I S is an i m p o r t a n t f a c t o r f o r t h e suc cess f u l de ve l o p me n t an d d i f f u s i o n o f ne w te c h n o l o g i es i n a c o u n t r y. F o r t h i s reaso n t he S o u t h A f r i c a n g o v e r n m e n t as ke d t he O E C D t o c o n d u c t a re v i e w o f t he S o u t h A f r i c a n N S I. S i n ce t he f i n d i n g s o f t h e O E C D re v i e w a lso i m pa c t o n t he r e c o m me n da t i o n s f o r a so la r ene r g y te c h n o l o g y r oa d m a p f o r S o u t h A f r i c a, so me ap p r o p r i a te aspec ts a re h i g h l i g h te d i n Ta b l e 25 (M j w a ra, 2007).

Table 25: S W OT analysis of the South African N S I (Source: Yaw, 2009)

Strengths:

• R eso u r ce-based i n d us t r i es an d re la t e d k n o w l e d ge-i n te ns i v e

b us i ness ser v i ces

• K n o w l e d ge i n f r as t r u c t u r e, a l be i t s ma l l i n re la t i o n t o t he s i ze

o f t he o ve r a l l p o p u l a t i o n

• H i g h p r o p o r t i o n o f B E R D an d G E R D

• I n d us t r i a l an d acade m i c i n te r na t i o na l ne t w o r k s

• P o l i t i c a l a w a r e ness o n t he i m p o r t a n ce o f sc ie n ce an d

tec h n o l o g y f o r sus ta i na b l e g r o w t h

Weaknesses:

• H u m a n r es o u r ce sh o r t a ges at a l l l e v e l s i n v o l v i n g m a t h e m a t i c s,

sc ie n ce an d tec h n o l o g y

• L a c k o f des i g n, en g i n ee r i n g, en t r e p r e ne u r i a l a n d m a na ge m e n t

ac t o r s an d R & D capa c i t y l ea d i n g t o an en g i n ee r i n g ga p

• M e n t a l m o d e ls o f h o w t he i n n o v a t i o n s ys te m o pe r a tes are o ve r-

f o c use d o n t he r o l e o f S ta te-G o v e r na n ce

Opportunities:

• B u i l d i n g o n t he e x i s t i n g i n n o v a t i o n s ys te m st r e n g t hs i n

i n d us t r y an d t he k n o w l e d ge i n f r as t r u c t u r e

• A t t r a c t F D I an d i n v es t m e n t t o esta b l i s h d u r a b l e S o u t h

A f r i ca n ca pac i t i es i n te r m s o f de v e l o p m e n t, ac q u i s i t i o n an d l ea r n i n g

• E x p l o i t l a t e n t ta l e n t o f t he m a j o r i t y

• B u i l d o n i n d us t r y-resea r c h sec t o r i n t e r ac t i o ns as ‘ f o c us i n g

de v i ces’ f o r de v e l o p i n g t he k n o w l e d ge i n f r as t r u c t u r e

Threats:

• D e m o g r a p h i c p r essu res o n ed u ca t i o n, r esear c h an d i n n o v a t i o n

s ys te ms

I n su m ma r y t he O E C D re v i e w tea m f o r t h e S o u t h A f r i c a n N S I f o u n d:

• H u m a n ca p i ta l f o r sc ie n ce, en g i n ee r i n g an d te c h n o l o g y su b-o p t i m a l;

• T h e g o v e r na n ce f r a m e w o r k nee ds m o r e v e r t i ca l an d h o r i z o n ta l i n te g r a t i o n;

• T h e r e i s an i n n o v a t i o n c has m w i t h an i ns u f f i c i e n t n u m be r o f r esea r c h p r o d u c ts d i r e c t l y i n f l u e n c i n g t he r ea l e c o n o m y ; an d

• S c ie n ce, en g i n ee r i n g an d i n n o v a t i o n f o r t h e 2 n dec o n o m y sh o u l d be m o r e v i s i b l e.

B ase d o n (i) t he st r u c t u r e o f t h e S o u t h A f r i c a n N S I i n te r ms o f s ta ke h o l d e rs (go ve r n m e n t, r esea r c h i ns t i t u t i o ns an d i n d u s t r y) an d (ii) so me st re n g t hs an d w ea k n esses o f t h e S o u t h A f r i c a n N S I (ava i l a b l e k n o w l e d ge i n f r as t r u c t u r e, i n d u s t r i a l an d aca de m i c i n t e r n a t i o na l ne t w o r k s, h u ma n res o u r ces sh o r ta ges i n sc ie n ce an d en g i n ee r i n g an d a l a c k o f des i g n / en g i n ee r i n g ca pa b i l i t y), t he d i f f e r e n t so la r te c h n o l o g i es i d e n t i f i e d i n sec t i o n 2 a re ana l yse d i n o r de r t o de te r m i ne t he i r pa r t i c u l a r st re n g t hs an d w ea k n esses.


2.1. P V systemsR esea r c h an d de v e l o p m e n t (R& D) i n S o u t h A f r i c a i n t he f i e l d o f P V te c h n o l o g y i s m a i n l y c o n ce n t ra te d at spec i f i c u n i v e rs i t i es na me l y :

• T h e U n i v e rs i t y o f Jo ha n nesb u r g (UJ) - t h i n-f i l m te c h n o l o g y ;

• T h e N e l s o n M a n d e l a M e t r o p o l i t a n U n i v e rs i t y (N M M U) - c ha ra c te r isa t i o n o f P V ce l l s, an d P V s ys te m des i g n;

• T h e U n i v e rs i t y o f P re t o r i a (UP) - t h i n f i l m resea r c h, s i l i c o n-based se m i c o n d u c t o r r esea r c h, c ha ra c te r isa t i o n o f P V ce l l s an d o p t i m i sa t i o n o f ene r g y s ys te ms; an d

• T h e U n i v e rs i t y o f F o r t H a r e (UF H) – ap p l i c a t i o n s, spec i f i c a l l y B I P V s.

O n t he P V s ys te m l e v e l so me ac t i v i t y i s ta k i n g p l a ce at t he C S I R, an d so me ap p l i ca t i o n de ve l o p m e n t i s a ls o ta k i n g p l a ce i n i n d u s t r y. N M M U an d U F H are a ls o resp o ns i b l e f o r t h e S A N E R I ‘s o l a r P V sp o k e’ v i a t he na t i o na l h u b; t he C e n t r e f o r R e ne w a b l e an d S us ta i n a b l e E ne r g y S t u d i es (CRS ES).

T h e f u t u re R & D ca pa b i l i t i es an d ac t i v i t i es f o r c o n v e n t i o na l P V te c h n o l o g i es i n S o u t h A f r i c a a re su m m a r i se d as

f o l l o w s:

• L i t t l e e x pe r t de v e l o p m e n t ca pa b i l i t y o n c r y s ta l l i n e s i l i c o n se m i c o n d u c t o r te c h n o l o g y e x i s ts i n S o u t h A f r i c a. E s ta b l i s h i n g su bs ta n t i a l l o ca l ca pac i t y i n t h i s r e ga r d i s p r o ba b l y n o t a p r i o r i t y f o r t h e ne x t y ea rs, t he r easo n be i n g t ha t t he w e l l-es ta b l i s he d, h i g h-l e v e l te c h n o l o g y, an d l a r g e i n v es te d f a c i l i t i es o v e rseas an d f r o m w h e r e l a r ge v o l u m es o f se m i c o n d u c t o r p r o d u c ts a re, an d w i l l i n f u t u r e be, i m p o r t e d.

• O f m u c h g r ea te r i m p o r t a n ce, h o w e v e r, i s t he e x pe r t ca pa b i l i t y es ta b l i s he d a t t h e N M M U an d t he U P i n t he c ha ra c te r isa t i o n o f se m i c o n d u c t o r s an d t he ac c o m pa n i e d P V s ys te ms. S i n ce S o u t h A f r i c a w i l l , f o r t h e f o r eseeab le f u t u re, be de pe n de n t o n i m p o r ts o f se m i c o n d u c t o r s, e x pe r t f a c i l i t i es t o ensu re h i g h q ua l i t y o f p r o d u c ts an d s ys te ms is o f t he u t m o s t i m p o r ta n ce. I n l i n e w i t h t h i s, p r i o r i t y sh o u l d be p u t o n t he de ve l o p me n t o f ap p r o p r i a te sta n da r ds f o r t h e p r o d u c ts an d s ys te ms. P r i o r i t i es f o r t h e ne x t y ea rs sh o u l d be t o:o E x p a n d t he e x i s t i n g tes t an d e va l u a t i o n ca pa b i l i t i es (fo r b o t h ce l l s an d s ys te ms) i n te r ms o f e x pe r t

s k i l l s an d eq u i p m e n t i n l a b o ra t o r i es;o D e v e l o p ap p r o p r i a te tes t an d e va l u a t i o n p r o ce d u r es, as w e l l as ap p r o p r i a te s ta n da r ds, an d o b t a i n

t he ne cessa r y i n te r n a t i o na l ac c re d i ta t i o n an d ce r t i f i c a t i o n; an do D e v e l o p an d i m p l e me n t t h e ne cessa r y t ra i n i n g an d resea r c h p r o g ra m m es at u n i v e r s i t i es i n o r de r t o

ensu re a sus ta i n a b l e su p p l y o f f u t u r e e x pe r ts i n t he f i e l d.

• A g o o d ca pac i t y f o r P V s ys te m des i g n (inc l u d i n g m o d u l e, s t r u c t u re an d t ra c k i n g s ys te m des i g n) an d o p t i m i sa t i o n ca pa b i l i t y (inc l u d i n g s ys te m tes t i n g ca pa b i l i t i es) e x i s ts w i t h i n i n s t i t u t i o ns su c h as t he N M M U , U S, U P an d t he C S I R. T h i s ca pa b i l i t y sh o u l d be f u r t he r de v e l o pe d at t h ese an d o t he r i n s t i t u t i o ns i n o r de r t o p r o v i d e a so l i d des i g n base f o r t he g r o w i n g i n d us t r y.

• A p p r o p r i a te e le c t r o n i c an d e le c t r i c a l c o m p o ne n t an d s ys te m de v e l o p me n t ca pa b i l i t i es e x i s t i n S o u t h A f r i c a, a l t h o u g h t he m a j o r a m o u n t o f t hese c o m p o n e n ts an d s ys te ms a re i m p o r t e d f r o m o v e rseas.

• A p p r o p r i a te i n s t i t u t i o ns sh o u l d, h o w e v e r, en ga ge i n t he de ve l o p m e n t o f s t o ra ge s ys te ms, e.g. ba t te r i es, f o r ap p l i c a t i o n s suc h as l i g h t i n g, t ra f f i c l i g h ts, an d o t he rs.

R e ga r d i n g f u t u re R & D ac t i v i t i es f o r c o n ce n t ra te d P V s ys te ms, t he sa me g u i d e l i n es f o r t he su b-s ys te ms as d i s c ussed f o r c o n v e n t i o na l P V s ys te ms a re ap p l i c a b l e. T h e ad d i t i o n o f an o p t i c a l su b-s ys te m (mi r r o r s an d l e nses) ta kes t h i s s ys te m t o a h i g he r l e v e l o f c o m p l e x i t y t ha n c o n v e n t i o na l P V s ys te ms. T h e f u t u re R & D c ha l l e n ge f o r c o n ce n t ra te d s ys te ms is t h us l a r ge r be ca use o f t h e h i g he r f u n c t i o na l an d pe r f o r m a n ce re q u i r e m e n ts se t f o r t hese s ys te ms. D e s i g n, tes t i n g, i n te g r a t i o n an d c os t ba la n c i n g o f c o m p l e x an d ac c u ra te o p t i c a l, t ra c k i n g, st r u c t u r a l, s t o ra ge an d e le c t r i c a l s ys te ms nee d ca re f u l a t te n t i o n. C o n ce n t r a te d P V s ys te ms see m t o be c o m e an i m p o r ta n t te c h n o l o g y p l a t f o r m i n t he ne x t 1 0 t o 1 5 y ea rs an d t he re i s n o d o u b t t h a t S o u t h A f r i c a sh o u l d p r e pa re a st r o n g, b u t ap p r o p r i a te te c h n o l o g i c a l ca pa b i l i t y base i n t h i s re ga r d.

U n l i k e w i t h t ra d i t i o na l se m i c o n d u c t o r so la r ce l l s w h e re l i t t l e e x pe r t i se e x i s t i n S o u t h A f r i c a f o r t h e r esea r c h o n an d de ve l o p me n t o f t h e ce l ls, a re la t i v e st r o n g R & D ca pa b i l i t y o n t h i n f i l m te c h n o l o g y i s a va i l a b l e i n t he c o u n t r y, espec i a l l y a t U J an d U P. F u t u re g r o w t h an d b r oa de r e x pa ns i o n o f t h i s ca pa b i l i t y sh o u l d be a h i g h p r i o r i t y o n t he w a y f o r w a r d. F u t u re R & D ca pa b i l i t i es an d ac t i v i t i es o n t h i n f i l m P V te c h n o l o g i es ca n be su m ma r i sed as f o l l o w s:

• T h e st re n g t he n i n g o f t he e x i s t i n g t h i n f i l m so la r ce l l R & D ca pa b i l i t i es t o c o n t i n ue l ea d i n g r esea r c h o n m a te r i a l s an d m a n u f a c t u r i n g p r o cesses i n o r de r t o i m p r o v e e f f i c i e n c i es an d l o w e r c os t. T h e r o l es o f u n i v e r s i t i es i n t h i s r e ga r d m u s t t o be e m p has ise d.

• I n ad d i t i o n, t he e x i s t i n g ca pa b i l i t i es a t t he N M M U an d U P (test i n g, e va l u a t i o n an d c ha ra c te r isa t i o n o f so la r ce l l s, s ta n da r ds de v e l o p m e n t an d ce r t i f i c a t i o n) sh o u l d be w e l l-l i n k e d t o ad va n ce me n ts i n t he t h i n f i l m so la r ce l l a re na.

• T h e f u t u r e de v e l o p me n t o f c o m p l e x m a n u f a c t u r i n g eq u i p m e n t i s c l ose l y l i n k e d t o ca pa b i l i t i es t ha t a l r ea d y e x i s t i n c o u n t r i es su c h as G e r m a n y an d t he U S A . I t i s o f t h e u t m os t i m p o r t a n ce t ha t t h e i n t e r na t i o na l c o l l a b o ra t i v e R & D ne t w o r k s a re f u r t he r de ve l o pe d. S o u t h A f r i c a, w i t h t he w o r k d o ne a t U J, i s ce r ta i n l y o ne o f t he c o u n t r i es i n t he f o r e f r o n t re ga r d i n g t he resea r c h an d de ve l o p me n t R & D o f t h i n f i l m so la r ce l l s. A pe r i o d o f i n te ns i v e resea r c h f r o m 1 993 t o 2004 w a s f o l l o w e d b y a pe r i o d o f i n n o v a t i o n o n a p i l o t m a n u f a c t u r i n g f a c i l i t y f r o m 2004 t o 2006. T h e te c h n o l o g y c o m m e r c i a l i sa t i o n p hase is c u r re n t l y i n p r o g r ess w i t h a G e r m a n pa r t ne r an d a 40 M W/an n u m m a n u f a c t u r i n g f a c i l i t y i s p l a n ne d t o be c o ns t r u c te d i n Paa r l i n t he W es te r n C a pe (A l be r ts, 2009), w i t h i n v es t me n ts o f Sas o l an d t he C e n t ra l E n e r g y F u n d (CEF).

A l b e r t s (2009) p resen te d an o u t l o o k o n f u t u r e te c h n i c a l an d pe r f o r m a n ce de v e l o p me n t f o r t he S o u t h A f r i c a n t h i n f i l m so la r ce l l te c h n o l o g y (see Ta b l e 26). T h e o v e ra l l S W O T ana l y s i s f o r R & D o f P V s ys te ms i n S o u t h A f r i c a i s sh o w n i n Ta b l e 27, an d t he f u n d i n g r e q u i r e m e n ts i n Ta b l e 28.

Table : F uture technical and performance development for thin film cells (Source: Alberts, 2009)

Parameter Area (cm2) P resent status Future goal (2013)

C h a m p i o n de v i ce e f f i c i e n c y 0.47 1 6.7 % 1 8 – 20 %

A v e r a ge de v i ce e f f i c i e n c y 5.0 1 5.5 % 1 7 – 1 8 %

A v e r a ge de v i ce e f f i c i e n c y 50.0 1 4.7 % 1 6 – 1 7 %

P i l o t m o d u l e e f f i c i e n c y 1 3 50 1 0 – 1 2 % 1 4 – 1 5 %

C o m m e r c i a l m o d u l e e f f i c i e n c y 7000 T F S T estab l i s he d 1 3 – 1 5 %

A l t e r na t i v e b u f f e r l a y e r s 7000 C d S I n 2S 3

S p u t t e r i n g p r o cesses 7000 P l a na r m a g ne t r o ns R o t a ta b l e m a g ne t r o ns

R ea c t i v e p r o cesses 7000 B a t c h d i f f u s i o n I n-l i ne d i f f u s i o n

S u bs t r a t es 7000 F l o a t g l ass F l e x i b l e f o i l

Table : S W OT analysis for P V systems in the South African N S I

Government R & D institutions I ndustry

Strengths • S o u t h A f r i ca as o ne o f t he bes t

so l a r i r r a d i a t i o n c o u n t r i es.

• C h a n ges i n S o u t h A f r i c a n

r e ne w a b l e ener g y p o l i c y, spe c i f i c a l l y t he i n t r o d u c t i o n o f R E F I T.

• G o v e r n m e n t su p p o r t o f

m a n u f a c t u r i n g, e.g. C e n t r a l E ne r g y F u n d f o r t h i n f i l m tec h n o l o g y.

• E s t a b l i s he d ca pab i l i t y i n test i n g

an d c ha ra c te r i s i n g se m i c o n d u c t o r s an d s ys te ms.

• G o o d ca pac i t y t o des i g n an d

o p t i m i se f u l l P V s ys te ms.

• G o o d e x pe r t i se i n t he R & D o f

t h i n f i l m tec h n o l o g y an d p r o d u c t s.

• A l r ea d y a ne t w o r k o f

m a n u f a c t u r e r s, d i s t r i b u t o r s an d r e ta i l e r s i n S o u t h A f r i ca.

• S t r o n g c o l l a b o r a t o r s su c h as

Saso l, E s k o m, E x x a r o an d H a t c h.

• E s t a b l i s he d su p p l y o f e le c t r o n i c

s ys te m c o m p o ne n t s.

Weaknesses • W ea k N S I.

• D o E s l o w i n en te r i n g so l a r

ene r g y m a r k e t.

• I n t e g r a te d p o l i c i es t o sup p o r t

m a n u f a c t u r i n g g r o w t h.

• L i t t l e e x pe r t ca pa b i l i t y i n

c r ys ta l l i n e s i l i c o n se m i c o n d u c t o r s.

• L i t t l e k n o w l e d ge e x c han ge

be t w ee n i ns t i t u t i o ns.

• H i g h ca p i t a l l a y o u t c os ts.

• S ma l l S A m a r k e t de m a n d.

• E x pe r i e n ce q ua l i t y p r o b l e m s.

Opportunities • I n t e r na t i o na l i n t e r es t i n t he S o u t h

A f r i c a n so l a r ene r g y i n d us t r y.

• D e d i ca te d resea r c h e f f o r t s can

c r ea te f as t l ea r n i n g c u r v es.

• E x pa n d tes t an d c ha r ac te r i s i n g

ca pab i l i t i es an d de ve l o p stan da r ds.

• R & D o f l o w an d h i g h o u t p u t

e le c t r i c i t y st o r a ge s ys te ms.

• E x pa n d p r o d u c t i o n ca pab i l i t i es,

espec i a l l y f o r t h i n f i l m.

• P V a f as t g r o w i n g g l o b a l

tec h n o l o g y.

• C os t c o m pe t i t i v e i n 20 y ea r s t i m e

f r a m e.

• S o u t h A f r i ca can e x p o r t e x pe r t i se

an d s ys te m c o m p o ne n t s; an d c o m p l e te s ys te ms i n t he case o f t h i n f i l m tec h n o l o g y.

• E s t a b l i s h t h i n f i l m m a n u f a c t u r i n g

f a c i l i t i es i n c o l l a b o r a t i o n w i t h l a r ge l o c a l an d f o r e i g n c o m p a n i es.

Threats • L a c k o f i n-t i m e de c i s i o n m a k i n g

o n l ea d i n g f u t u r e so l a r ene r g y p r o j e c t s.

• L a c k i n t r a i n i n g o f su f f i c i e n t

sc i e n ce an d tec h n o l o g y s k i l l s.


tec h n i ca l an d m a n u f a c t u r i n g s k i l l s.

Table : F unding requirements for P V R & D in South Africa

Research1 Development2

P V conventional concentrated

• Se m i c o n d u c t o r c ha ra c te r i sa t i o n an d tes t i n g.

• E l e c t r i c i t y st o ra ge tec h n o l o g y.

• S y s te m an d sub-s ys te m des i g n an d o p t i m i sa t i o n

i n c l u d i n g st r u c t u r es an d t r ac k i n g.

• E l e c t r i c i t y st o r a ge tec h n o l o g y.

• I m p r o v e d o p t i ca l s ys te ms.

Thin film • L o w e r c os t, h i g h e r e f f i c i e n c y t h i n f i l m p r o d u c t an d

m a n u f a c t u r i n g tec h n o l o g y.

• S y s te m an d sub-s ys te m des i g n an d o p t i m i sa t i o n.

• T h i n f i l m m a n u f a c t u r i n g tec h n o l o g y.

1 . R esear c h f u n d i n g m a i n l y f r o m de d i ca te d g o v e r n m e n t f u n ds.

2. D e v e l o p m e n t f u n ds m a i n l y f r o m e x is t i n g g o v e r n m e n t f u n ds su c h as t he I n n o v a t i o n F u n d an d f r o m t he C e n t r a l E ne r g y F u n d, an d t h us

a va i l a b l e o n suc cess f u l a p p l i ca t i o n, as w e l l as f r o m i n d us t r y i n v es t m e n t su c h as Saso l an d E s k o m.

2.2. CS P systemsT h e m a i n C SP te c h n o l o g i es ca n i n b r oa d te r ms be c ha ra c te r i se d as f o l l o w s:

• P arabolic trough : T h e te c h n o l o g y i s t he m o s t m a t u r e o f t he C SP te c h n o l o g i es an d t he te c h n o l o g y de ve l o p me n t r i s k i s r e la t i v e l y l o w. T h e te c h n o l o g y i s a ls o ap p r o p r i a te f o r h i g h M W o u t p u t (even l a r g e r

t ha n 300 M W), w h i c h i s ad va n ta ge o us t o r e d u ce u n i t c os ts. T h e a va i l a b i l i t y o f s t o ra ge is l i m i t e d, b u t t he s ys te m l e n ds i t se l f t o h y b r i d des i g ns. Pa ra b o l i c t r o u g h te c h n o l o g y c o u l d p oss i b l y be t he c h o i c e o f S o u t h A f r i c a n c o m p a n i es t o ge ne ra te e le c t r i c i t y a t l a r ge p l a n ts o r f a c i l i t i es.

• Central receivers: T h e te c h n o l o g y ca n be c o ns i de re d as i n t he sca le-u p de m o ns t ra t i o n p hase w i t h m e d i u m te c h n o l o g y r i s k. T h i s i s ap p r o p r i a te te c h n o l o g y f o r o u t p u ts u p t o 200 M W. S t o r a ge te c h n o l o g y i s a va i l a b le an d ce n t ra l re ce i v e rs l e n d t he m t o h y b r i d des i g ns. C e n t r a l re ce i v e r te c h n o l o g y see ms t o be c h o i c e f o r E s k o m f o r t he m e d i u m t o l o n g f u t u r e an d te c h n o-ec o n o m i c f eas i b i l i t y s t u d i es i n t h i s r e ga r d a re i n an ad va n ce d sta ge.

• L inear F resnel: A l t h o u g h t h i s te c h n o l o g y i s c ha ra c te r i se d b y l o w e r e f f i c i e n c i es an d l o w e r res is ta n ce t o t he na t u r a l e le m e n ts suc h as w i n d, l i n ea r F r es ne l s ys te ms ha v e t he ad v a n ta ge o f l o w c os t. B e ca use o f i t s l o w e r e f f i c i e n c y t he te c h n o l o g y i s ap p r o p r i a te f o r l o w e r o u t p u ts. T h i s m a k es t he te c h n o l o g y at t ra c t i v e f o r o f f-g r i d use, o r f o r usa ge w i t h l a r g e b u i l d i n g s; h o w e v e r, t h i s has y e t t o be de m o ns t ra te d e f f e c t i v e l y i n t he S o u t h A f r i c a n c o n t e x t an d i t i s t he re f o r e c o ns i de re d t o be a m e d i u m r i s k te c h n o l o g y.

• D ish Stirling: T h e te c h n o l o g y i s i n a p r o t o t y pe de m o ns t ra t i o n sta ge w i t h h i g h te c h n o l o g y r i s k. O u t p u ts a re ta r ge te d at t he l o w e r r a n ges (less t ha n 25 k W). B a t te r i es a re use d f o r s t o ra ge p u r p oses an d t he s ys te m l e n ds i t se l f t o h y b r i d des i g ns. H o w e v e r, u p t o n o w t h i s te c h n o l o g y has n o t bee n tes te d suc cess f u l l y i n S o u t h A f r i c a an d t h us d i d n o t ga i n m u c h p o p u l a r i t y. I t i s so me t i m es t he t o p i c o f r esea r c h f o r p os t-g r a d ua te st u de n ts a t u n i v e r s i t i es.

F r o m a ge ne r i c C SP s ys te m pe rs pe c t i v e t he R & D sta t us o f t he v a r i o us su bs ys te ms ca n be c lass i f i e d as f o l l o w s:

• Reflector sub-system : N o t m u c h resea r c h nee de d, b u t m a n u f a c t u r i n g ca pa b i l i t y m u s t be de ve l o pe d.

• Orientation control: W e l l-es ta b l i s he d.

• Absorber / receiver: R esea r c h nee de d, espec i a l l y o n t he t he r m a l-ca r r y i n g f l u i ds.

• Structures: W e l l-es ta b l i s h e d.

• Storage sub-system: R esea r c h nee de d.• P ower cycle sub-system: D e v e l o p m e n t nee de d espec i a l l y t he e x i s t i n g d r y-a i r an d h y b r i d c o o l i n g

ca pa b i l i t i es i n t he c o u n t r y.

V a r i o u s pas t, p r esen t an d f u t u r e R & D ac t i v i t i es a t S o u t h A f r i c a n resea r c h i n s t i t u t i o ns ha ve bee n re p o r te d an d a re su m ma r i sed i n Ta b l e 29. A S W O T ana l y ses i s p r o v i d e d i n Ta b l e 30.

Table : Reported R & D activities per technology area in South Africa

Technology area Past and P resent R & D Future R & D International

partners

S y s te ms M o d e l l i n g an d A n a l y s i s

• 1 00 M W e U p i n g t o n p o w e r p l a n t b y

E S K O M .

• S o l a r G as T u r b i ne p r o j e c t a t t he C S I R.

• M e e r K a t p r o j e c t a t S t e l l e n b os c h

U n i v e r s i t y.

• S u nSP O T H y b r i d (Co m b i ne d C y c l e) S o l a r

P o w e r S t a t i o n at S te l l e n b os c h U n i v e r s i t y.

• C SP P l a n t m o de l l i n g,

i n c l u d i n g c o l l e c t o r, re ce i v e r, p o w e r b l o c k an d c o o l i n g s ys te m t o o p t i m i se p l a n t pe r f o r m a n ce f o r se le c te d tec h n o l o g y an d so l a r r es o u r ce.

• C os t m o de l l i n g an d

o p t i m i sa t i o n.

I S E i n G e r m a n y,

F r a u n h o f e r I n s t i t u t e i n G e r m a n y,

D L R i n G e r m a n y,

N R E L i n t he U S A ,

S o l a r M i l l e n n i u m.

P o w e r b l o c k • D e v e l o p m e n t o f a so l a r d r i v e n gas t u r b i n e

en g i ne at t he C S I R i n c o l l a b o r a t i o n w i t h S t e l l e n b os c h U n i v e r s i t y.

• S u nSP O T H y b r i d S o l a r P o w e r sta t i o n,

S t e l l e n b os c h U n i v e r s i t y.

• C os t o p t i m i sa t i o n.

• H y b r i d o pe ra t i o n.

D L R i n G e r m a n y, T u r b e c i n I t a l y.

M a t e r i a l s tec h n o l o g y

(Sto ra ge)

• Sa l t st o r a ge o n 1 00 M W e C SP p l a n t,

E S K O M .

• S t o r a ge f o r so la r gas t u r b i n e p r o j e c t, C S I R.

• U s i n g l o c a l l y sou r ce d m a t e r i a l s f o r t he r m a l

st o ra ge, o n g o i n g r esear c h p r o j e c t a t S t e l l e n b os c h U n i v e r s i t y.

• C os t e f f i c i e n t st o ra ge

m e d i u m s.

• P hase c han ge m a t e r i a l s.

• H i g h te m pe ra t u r e t he r m a l

st o ra ge.

• A l t e r na t i v e c o n c ep t s.


S o l a r I ns t i t u t e Jü l i c h i n G e r m a n y, N R E L i n t he U S A , A b e n g oa S o l a r i n S pa i n.

C o o l i n g tec h n o l o g y

(Dr y/H y b r i d/Wet)• E x t e ns i v e r esea r c h at S te l l e n b osc h

U n i v e r s i t y f o r m a n y y ea r s i n t o d r y-a i r c o o l i n g s ys te ms f o r m a i n l y c oa l-f i r e d p o w e r sta t i o ns, M a t i m ba an d M e d u p i.

• Es k o m o pe r a tes M a t i m b a, o ne o f t he

l a r ges t d r y-a i r c o o l e d p o w e r sta t i o ns i n t he w o r l d.

• H y b r i d c o o l i n g s ys te ms f o r

C SP p l a n t s i n ar i d areas.

• Fa n o p t i m i sa t i o n.

• A d v a n c ed d r y-an d h y b r i d

c o o l i n g s ys te ms.

D L R an d G E A , b o t h i n G e r m a n y.

Pa ra b o l i c t r o u g h an d ce n t r a l re ce i v e r c o l l e c t i o n subs ys te ms

• A u t o m a te d t r o u g h des i g ne d, b u i l t a n d

c o m m i ss i o n e d at M a n g os u t h u U n i v e r s i t y o f Te c h n o l o g y (M U T).

• U n d e r g r a d ua te st u de n t p r o j e c ts a t t he S o l a r

R o o f L a b o r a t o r y, S t e l l e n b os c h U n i v e r s i t y.

• L o w e r c os t m i r r o r s.

• L o w e r c os t r ece i v e r s.

• A l t e r na t i v e hea t t r a ns f e r

f l u i d s.

I S E i n G e r m a n y,

F r a u n h o f e r I n s t i t u t e i n G e r m a n y,


N R E L i n t he U S A , Sc h o t t a n d S o l e l.

Table : S W OT analysis for C S P systems in the South African N S I


Strengths • S o u t h A f r i ca as o n e o f t he bes t

so l a r i r r a d i a t i o n c o u n t r i es.

• C h a n ges i n S o u t h A f r i c a n

r e ne w a b l e ener g y p o l i c y, spe c i f i c a l l y t he i n t r o d u c t i o n o f R E F I T.

• G o v e r n m e n t su p p o r t o f

tec h n o l o g y de v e l o p m e n t t h r o u g h t he C l ea n Te c h n o l o g y F u n d.

• A w e l l-estab l i s he d ne t w o r k o f

i n te r na t i o n a l resear c h c o l l a b o r a t o r s i n t he C SP tec h n o l o g y f i e l d.

• W e l l-estab l i s he d l o ca l R & D

g r o u ps at v a r i o us S o u t h A f r i ca n u n i v e r s i t i es an d t he C S I R.

• E s t a b l i s he d ca pab i l i t y i n t he

m o de l l i n g an d ana l y s i s o f C SP s ys te ms.

• E x ce l l e n t l o ca l pas t e x pe r i e n ce i n

tec h n o l o g i es suc h as d r y-c o o l i n g, f l u i d d y na m i cs, e t c.

• A l r ea d y a ne t w o r k o f

m a n u f a c t u r e r s, d i s t r i b u t o r s an d r e ta i l e r s i n S o u t h A f r i ca.

• S t r o n g c o l l a b o r a t o r s su c h as

Saso l, E s k o m, E x x a r o an d H a t c h.

• E s t a b l i s he d su p p l y o f e le c t r o n i c

s ys te m c o m p o ne n t s.

Weaknesses • W ea k N S I.

• D o E s l o w i n en te r i n g so l a r

ene r g y m a r k e t.

• I n t e g r a te d p o l i c i es t o sup p o r t

m a n u f a c t u r i n g g r o w t h.

• S o u t h A f r i ca c u r r e n t l y d oes n o t

ha v e a l a r ge sca le p r o j e c t t o st i m u l a te f u r t he r R & D o n sub-s ys te m l e v e l.

• S o u t h A f r i ca c u r r e n t l y d oes n o t

ha v e a l a r ge sca le p r o j e c t t o ga i n v a l u a b l e e x pe r i e n ce i n m a n u f a c t u r i n g an d o pe ra t i o ns.

Opportunities • I n t e r na t i o na l i n t e r es t i n t he S o u t h

A f r i c a n so l a r ene r g y i n d us t r y.

• D e d i ca te d resea r c h e f f o r t s can

c r ea te f as t l ea r n i n g c u r v es.

• F u n d resear c h p r o j e c t s i n areas

su c h as st o ra ge, abs o r be r f l u i d s, h y b r i d des i g n, e t c.

• O p p o r t u n i t i es t o t r a ns f e r

ap p r o p r i a t e tec h n o l o g y f r o m i n te r na t i o n a l c o l l a b o r a t o r s.

• T h e ap p r o v a l o f l a r ge p r o j e c t(s)

b y e.g. Es k o m an d S K A t o esta b l i s h t he base tec h n o l o g i es f o r a c o m p l e t e s ys te m.

Threats • L a c k o f i n-t i m e de c i s i o n m a k i n g

o n l ea d i n g f u t u r e so l a r ene r g y p r o j e c t s.





• H i g h ca p i t a l l a y o u t c os ts.

3. Thermal heating and cooling applicationsT h e t w o m a i n ca teg o r i es o f t h e r m a l hea t i n g te c h n o l o g y ca n i n b r oa d te r ms be c ha ra c te r ise d as f o l l o w s:

• N o n-t ra c k i n g ap p l i ca t i o ns: T h ese te c h n o l o g i es a re t y p i c a l l y ap p l i e d t o re la t i v e l o w te m pe ra t u r e ap p l i c a t i o ns (typ i c a l l y l ess t ha n 1 50º C) su c h as c o n v e n t i o na l so l a r c o o k i n g, hea t i n g an d c o o l i n g ap p l i c a t i o ns f o r h o mes, l a r ge b u i l d i n gs an d t he ag r i c u l t u r a l i n d us t r y. I n te r na t i o na l l y l ess r esea r c h i s de d i ca te d t o n o n-t ra c k i n g t he r m a l hea t i n g an d c o o l i n g te c h n o l o g y; m a te r i a l s an d d i f f e r e n t c o n f i g u r a t i o n, suc h as c o n ce n t ra t i n g f l a t p l a te s ys te ms, a re i n v es t i g a te d, b u t w i t h o u t l a r g e f u n d i n g an d i ns t i t u t i o na l su p p o r t. M o s t e f f o r t s a re o n de ve l o p me n t w o r k d o ne o n stan da r d i sa t i o n, q ua l i t y tes t i n g an d s ma l l-sca le

ap p l i c a t i o ns. T h e e x pa ns i o n o f t h e e x i s t i n g R & D ca pa c i t y i n t h i s re ga r d w i l l be t he r esp o ns i b i l i t y o f b o t h i n d us t r y an d g o v e r n m e n t; p r o ba b l y r e p rese n te d b y, f o r e xa m p l e, t he S A B S (fo r sta n da r d i sa t i o n an d q ua l i t y tes t i n g). T h e ne x t 20 y ea rs i n S o u t h A f r i c a f o r n o n-t ra c k i n g t he r m a l hea t i n g w i l l , i n a l l l i k e l i h o o d, be d o m i n a te d b y t he re ce n t l y re leased st ra te g i c f r a m e w o r k an d i m p l e me n ta t i o n p l a n f o r so l a r w a te r hea t i n g b y t he D e p a r t m e n t o f E n e r g y (Do E, 2009). T h e f o c us o f t h i s s t ra te g y w i l l be o n ‘a l i m i t e d ra n ge o f p r o v e n te c h n o l o g y ’ an d ca pac i t y b u i l d i n g w i t h de d i ca te d s k i l l s t ra i n i n g an d ac c re d i ta t i o n (Yaw, 2009). H o w e v e r, t h e p o t e n t i a l p r o cess hea t ap p l i ca t i o ns o f l ess t ha n 200º C, f o r c o m m e r c i a l, ag r i c u l t u r e an d i n d us t r i a l p u r p oses, sh o u l d n o t be o v e r l o o k e d, espec ia l l y t h r o u g h e va c ua te d t u be an d c o n ce n t ra t i n g f l a t p l a te s ys te ms.

• T r a c k i n g ap p l i c a t i o ns: T h ese te c h n o l o g i es a re t y p i c a l l y ap p l i e d t o re l a t i v e h i g h te m pe ra t u r e ap p l i c a t i o n s suc h as t o ge ne ra te i n d u s t r y p r o cess hea t (less t ha n 400º C) an d so la r t h e r m o-c he m i ca l / f u r na ces / gas i f i c a t i o n / desa l i n a t i o n ap p l i ca t i o ns (more t ha n 1 50º C) i n l a r ge b u i l d i n g, ag r i c u l t u ra l an d i n d us t r i a l p l a n t en v i r o n me n ts. I n te r n a t i o na l l y t he re i s a c o n t i n u o us resea r c h f o c us o n p o te n t i a l ap p l i c a t i o ns f o r t ra c k i n g t he r m a l hea t i n g an d c o o l i n g te c h n o l o g y, espec i a l l y i n t he h i g he r (large r t h a n 400º C) te m pe r a t u re r a n ges. I n S o u t h A f r i c a t he e m p has is i s c u r r e n t l y o n e x p l o r a t o r y, te c h n i c a l-l e v e l resea r c h, b u t w i t h m o r e, de d i ca te d e f f o r t t he c o n t r i b u t i o n o f so la r s ys te ms i n t h i s d o ma i n ca n be s i g n i f i c a n t t o r e d u ce t he ca r b o n i n t e ns i t y o f t h e ec o n o m y.

Table : S W OT analysis for thermal applications in the South African N S I


Strengths • R e l ease o f t he c o n ce p t st r a t e g i c

f r a m e w o r k an d i m p l e m e n t a t i o n p l a n f o r S W H s b y t he D o E.

• E s t a b l i s he d R & D capa c i t y f o r

stan da r d i sa t i o n, q ua l i t y test i n g an d sma l l-sca le de v e l o p m e n ts i n l o w e r te m pe r a t u r e ap p l i ca t i o ns.

• E s t a b l i s he d st r o n g ne t w o r k o f

m a n u f a c t u r e r s, d i s t r i b u t o r s an d r e ta i l e r s i n S o u t h A f r i ca f o r l o w e r te m pe r a t u re ap p l i ca t i o ns su c h as S W H s f o r h o m es.

Weaknesses • D o E s l o w i n i m p l e m e n t i n g

p o l i c i es.

• R & D i ns t i t u t i o ns i n S o u t h A f r i c a

c u r r e n t l y d o n o t p r i o r i t i se r esea r c h i n t r a c k i n g t he r m a l hea t i n g an d c o o l i n g ap p l i ca t i o ns.

• C u r r e n t l y n o t a h i g h p r i o r i t y f o r

t r a c k i n g t he r m a l hea t i n g an d c o o l i n g ap p l i ca t i o ns i n t he S o u t h A f r i c a n i n d us t r y.

Opportunities • Q u i c k i m p l e m e n t a t i o n o f t he

p r o p osed S W H st r a te g i c f r a m e w o r k an d i m p l e m e n t a t i o n p l a n.

• I n d u s t r y sh o u l d i n i t i a t e an d f u n d

R & D p r o j e c ts o n h i g h te m pe r a t u re t r a c k i n g t he r m a l hea t i n g an d c o o l i n g tec h n o l o g y an d ap p l i ca t i o ns at u n i v e r s i t i es an d t he C S I R.

• I n i t i a t i o n o f l a r ge i n d us t r i a l

p r o j e c t s f o r t he use o f t r a c k i n g t he r m a l hea t i n g an d c o o l i n g tec h n o l o g y f o r ap p l i ca t i o ns suc h as gas i f i c a t i o n, f u r na ces, t he r m o-c he m i c a l p r o cesses an d desa l i n a t i o n.

Threats • S l o w t o m o v e be y o n d t he S W H

st r a te g i c f r a m e w o r k an d i m p l e m e n t a t i o n p l a n.





5. T H E S ET R M FO R SOUT H A F R I C A

1. R & D visionT h e v i s i o n o f t h e S o u t h A f r i c a n R & D c o m m u n i t y i s t o u t i l i se t he c o m p a ra t i v e ad v a n ta ge o f so la r i r r a d i a t i o n o f t he c o u n t r y t o ad d r ess so me o f t he c ha l l e n ges t ha t a re f a ce d b y:

• E s ta b l i s h i n g R & D f a c i l i t i es f o r t h e ap p r o p r i a te an d p r i o r i t i se d so la r te c h n o l o g i c a l s ys te ms;

• B u i l d i n g e x pe r t ca pac i t i es o f sc ie n t i s ts, en g i n ee rs an d te c h n i c i a ns;

• Pu t t i n g ap p r o p r i a te p o l i c i es i n p l a ce t o st i m u l a te t he R & D , d r i v e n f r o m b o t h g o v e r n me n t an d i n d us t r y;

• E s ta b l i s h i n g ap p r o p r i a te f u n d i n g m e c h a n i s ms (go ve r n me n t an d i n d us t r y) t o st i m u l a te R & D ; an d

• D e v e l o p i n g st r o n g d i f f u s i o n m e c h a n i s ms f o r so la r k n o w l e d ge an d te c h n o l o g y, i n c l u d i n g k n o w l e d ge f r o m f o r e i g n as w e l l as l o ca l so u r ces.

I n o t he r w o r d s, t he v i s i o n i s t o st re n g t h e n t he N S I pe r ta i n i n g t o t he so la r sec t o r w i t h g l o ba l R & D i ns t i t u t i o n s.

2. R & D strategies2.1. R & D funding

T h r ee ca te g o r i es o f resea r c h f u n d i n g a re en v i sa ge d t o su p p o r t t h e R & D v i s i o n:

• M a i n R & D p r i o r i t i es t ha t a re f u n d e d b y g o v e r n m e n t t h r o u g h spec i a l l o ca l an d i n te r n a t i o na l f u n d i n g st rea ms su c h as t he c lea n te c h n o l o g y f u n ds (Go ve r n me n t o f S o u t h A f r i c a, 2009; W o r l d B a n k, 2009), c ha i rs a t u n i v e r s i t i es, ce n t res o f e x pe r t i se, an d o t he rs.

• R esea r c h p r o j e c ts t ha t a re f u n d e d b y g o v e r n m e n t t h r o u g h e x i s t i n g f u n d i n g m e c ha n i s ms suc h as t he I n n o v a t i o n F u n d an d o t he rs, as w e l l as i n te r n a t i o na l f u n d i n g m e c h a n i s ms suc h as t he E u r o p ea n U n i o n F P7 p r o g r a m m e, w h e r e u n i v e rs i t i es, t h e C S I R an d c o m p a n i es ca n ap p l y f o r f u n d i n g.

• M a r k e t p u l l p r o j e c ts w h e r e t he l a r ge c o m pa n i es suc h as Sas o l, E s k o m, E x x a r o, a m o n gs t o t he rs, i n i t i a te l a r g e so la r p r o j e c ts an d a ls o c o n t ra c t R & D o u t t o t he ap p r o p r i a te i n s t i t u t i o n s.

S ma l l resea r c h p r o j e c ts o n t he l o w e r p r i o r i t y so la r te c h n o l o g i es suc h as t he so la r c h i m n e y, d i s h S t i r l i n g, an d o t he rs, w i l l a l w a ys be d o ne a t u n i v e r s i t i es as pa r t o f st u de n t r esea r c h p r o j e c ts an d t heses an d t hese ac t i v i t i es w i l l be f u n de d t h r o u g h t he c o n v e n t i o na l m e c ha n i s ms o f g o v e r n m e n t an d i n d u s t r y.

2.2. R & D and other prioritiesT h e R & D re q u i r e m e n ts o f t he d i f f e re n t te c h n o l o g i es, as w e l l as t he r e q u i r e m e n ts o f t h ose te c h n o l o g i es t ha t ha ve bee n de m o ns t ra te d, w h i c h nee d t o be c o m m e r c i a l i se d i n S o u t h A f r i c a, an d t h ose t ha t a re a l rea d y c o m m e r c i a l i se d an d ca n t he re f o r e be ac q u i r e d d i re c t l y, a re su m ma r i sed i n Ta b l e 32.

Table : M arket readiness in South Africa of the different technological systems






Power – P hotovoltaic

C o n v e n t i o n a l • R & D f o c us o n

c ha r ac te r i sa t i o n o f se m i c o n d u c t o r s.




f o r i m p r o v e d an d ne w ge ne r a t i o n st o r a ge tec h n o l o g i es.

• O p t i m i se o p t i ca l s ys te m

tec h n o l o g i es f o r p r o d u c t an d m a n u f a c t u r i n g.

• E x p a ns i o n o f e x i s t i n g

s ys te m des i g n, s i m u l a t i o n an d o p t i m i sa t i o n capa b i l i t i es, i n c l u d i n g pa ne l, st r u c t u r e an d t r ac k i n g s ys te ms.

√

E x i s t i n g i n d us t r y, l o c a l an d g l o b a l.

C o n ce n t r a t e d √

T h i n f i l m • E x pa ns i o n o f f a c i l i t i es

f o r R & D o n l o w c os t an d h i g h e f f i c i e n c y t h i n f i l m p r o d u c t s.


c ha r ac te r i sa t i o n an d tes t i n g capa b i l i t i es.

• R & D t o o p t i m i se

m a n u f a c t u r i n g tec h n o l o g i es.

√

Saso l,

C E F,

T h i n F i l m S o l a r Te c h n o l o g i es,

O t h e r s g l o b a l l y.

Concentrated solar power






Pa ra b o l i c t r o u g h • E x pa ns i o n o f e x i s t i n g

s ys te m des i g n, s i m u l a t i o n an d o p t i m i sa t i o n ca pab i l i t i es, i n c l u d i n g st r u c t u r e an d t r ac k i n g s ys te ms, an d d r y c o o l i n g f o r t he p o w e r b l o c k.





• O p t i m i se r ece i v e r

s ys te m tec h n o l o g i es f o r p r o d u c t s an d m a n u f a c t u r i n g

√

M i n i n g h o uses an d o t he r c o m pa n i es w i t h l a r ge f a c i l i t i es / p l a n t s.

C e n t r a l r ece i v e r s • O p t i m i se re ce i v e r

s ys te m tec h n o l o g i es f o r p r o d u c t s an d m a n u f a c t u r i n g.


s ys te m des i g n, s i m u l a t i o n an d o p t i m i sa t i o n ca pab i l i t i es, i n c l u d i n g st r u c t u r e an d he l i o s t a t s ys te ms, an d d r y c o o l i n g f o r t he p o w e r b l o c k.





√

Es k o m, S K A (Meer K a t), so l a r pa r k s.

L i n ea r F r es ne l • A s w i t h pa ra b o l i c

t r o u g h √

I n d us t r i a l p l a n t s, c o m m e r c i a l b u i l d i n gs, o f f-g r i d use rs.

D i s h S t i r l i n g √ R & D i ns t i t u t i o ns, c o m m e r c i a l b u i l d i n gs.

Thermal

N o n-t ra c k i n g c o l l e c t o r s

• N o n e en v i sa ge dS y s te m o p t i m i sa t i o n resear c h p r o j e c t s

√ N e w D o E f r a m e w o r k.

C o n ce n t r a t e d w i t h t r a c k i n g

• A s w i t h pa ra b o l i c

t r o u g h an d l i n ea r F r es ne l w i t h o u t t he p o w e r b l o c k

√

I n d us t r i a l p l a n t s an d ag r i c u l t u r e.

Other

R eso u r ce assess me n t an d m a p p i n g

• R esea r c h f o c us o n

m easu r e m e n t an d da ta ana l y s i s

E s ta b l i s h de d i ca te d reso u r ce assess me n t i ns t i t u t i o n/s √

G o v e r n m e n t,

E s k o m, l a r ge c o m pa n i es.

S t a n da r ds an d test i n g • D e v e l o p m e n t o f q ua l i t y

tes t i n g capa b i l i t i es√

G o v e r n m e n t, m a n u f a c t u r i n g i n d us t r y.

√ Denotes the life cycle phase of the technological system

3. R & D implementationT h ose te c h n o l o g i c a l p l a t f o r m s t ha t a re i n t he de m o ns t ra te d an d c o m m e r c i a l i se d l i f e c y c l e p hase (see Ta b l e 32) w e re f u r t h e r ana l y se d i n te r ms o f :

• G o v e r n m e n t i n t e ns i t y i n te r ms o f t he re q u i r e m e n t f o r t h ose te c h n o l o g i c a l p l a t f o r m s t ha t w o u l d st i m u l a te ec o n o m i c g r o w t h c o u p l e d w i t h i n d u s t r y de ve l o p me n t an d e m p l o y m e n t c r ea t i o n, t h ose t ha t w o u l d i m p r o v e ene r g y sec u r i t y an d ac cess, an d t h ose t ha t w o u l d ad d ress c l i m a t e c ha n ge;

• I n d u s t r y i n te ns i t y i n te r ms o f t h ose te c h n o l o g i c a l p l a t f o r m s t ha t c o u l d e x pa n d a l o ca l su p p l y c ha i n, an d l ea d t o a g r ea te r e x p o r t p o t e n t i a l o f p r o d u c ts, te c h n o l o g i es an d k n o w l e d ge; an d

• R & D i n t e ns i t y i n te r ms o f a va i l a b l e ca pa c i t y an d asso c i a te res o u r ces nee de d t o su p p o r t t he f u r t h e r de ve l o p me n t o f t h e te c h n o l o g i c a l p l a t f o r m s.

T h e ana l y s i s i s su m ma r i sed i n F i g u r e 76.

3.1. Short term – next five yearsTa b le 32 an d F i g u r e 76 sh o w t he e i g h t te c h n o l o g i c a l s ys te ms ha v e c l ea r l y bee n de m o ns t ra te d o r c o m m e r c i a l i se d, w h e r e a l o ca l i n d us t r y c o u l d be st i m u l a te d (w i t h t he p o t e n t i a l o f e x p o r t o p p o r t u n i t i es) an d t he o t he r r e q u i r e m e n ts o f g o v e r n m e n t ca n be m e t, an d t ha t ha v e a m e d i u m t o h i g h R & D i n te ns i t y :

• P V s ys te ms (con ce n t ra te d an d t h i n f i l m) w i t h st o ra ge f o r l ess t ha n 500 k W p o w e r su p p l y, t y p i c a l l y f o r o f f-g r i d an d c o m m e r c i a l b u i l d i n g ap p l i c a t i o n s;

• P V s ys te ms (con ce n t ra te d an d t h i n f i l m) w i t h o u t s t o ra ge f o r m o r e t ha n 1 M W g r i d-c o n nec te d p o w e r su p p l y ;

• C SP s ys te ms (parab o l i c t r o u g h, l i n ea r F r es ne l an d ce n t ra l re ce i v e r) w i t h o u t s t o ra ge f o r l ess t ha n 1 0 M W g r i d-c o n ne c te d p o w e r su p p l y ;

• C SP s ys te ms (parab o l i c t r o u g h an d ce n t ra l re ce i v e r) w i t h st o ra ge f o r m o r e t ha n 50 M W g r i d-c o n ne c te d p o w e r su p p l y ;

• So l a r hea t i n g s ys te ms (non-t ra c k i n g an d s i m p l e pa ra b o l i c t r o u g h) f o r p r o cess hea t o f l ess t ha n 1 50º C;

• So l a r hea t i n g s ys te ms (parab o l i c t r o u g h an d l i n ea r F r esne l) f o r p r o cess hea t o f l ess t ha n 250º C;

• So l a r hea t i n g s ys te ms (ad va n ce d pa ra b o l i c t r o u g h an d l i n ea r F r es ne l) f o r p r o cess hea t o f f l ess t ha n 400º C; an d

• So l a r hea t i n g s ys te ms (cent ra l re ce i v e r) f o r t h e r m o c he m i s t r y hea t o f m o r e t ha n 750º C.

F u r t h e r m o r e, res o u r ce assess me n t an d m a p p i n g is re q u i r e d i n t he sh o r t te r m an d stan da r ds an d tes t i n g f a c i l i t i es nee d t o be esta b l i s h e d an d su p p o r te d, n o t o n l y f o r t h e e i g h t p r i o r i t i se d te c h n o l o g i c a l s ys te ms, b u t a ls o f o r t h ose t ha t ha v e a l rea d y bee n c o m m e r c i a l i se d an d re q u i r e l ess R & D i n t e r v e n t i o n s.

A - Conventional photovoltaic

B - Concentrated photovoltaic

C - Thin film photovoltaic

D - Parabolic trough, power and thermal

E - Central receiver, power and thermal

F - Non-tracking collectors, thermal

G - Resource mapping (enabler)

H - Standards and test ing (enabler)

Medium

Low Medium High

A

B

Government intensity

Industry intensity

Low R&D intensity

Medium R&D intensity

High R&D intensity

C

D F

G

H

E

Figure : A nalysis of the technological platforms in terms of government, industry and R & D intensities

3.2. Short to medium term – next ten yearsI n t h e sh o r t t o m e d i u m te r m R & D res o u r ces nee d t o be d i r e c te d o n a c o n t i n ua l bas is t o su p p o r t t he f o u r p r i o r i t i se d an d o t he r te c h n o l o g i c a l s ys te ms t ha t a re i n t he c o m me r c i a l i sa t i o n p hase:

• C o n v e n t i o na l an d c o n ce n t ra te d P V s ys te ms f o r p o w e r ap p l i ca t i o ns: R & D f o c us o n t he c ha ra c te r isa t i o n o f se m i c o n d u c t o r s; de ve l o p me n t o f ap p r o p r i a te ed u ca t i o n an d t ra i n i n g p r o g r a m m es; an d esta b l i s h i n g R & D f a c i l i t i es f o r i m p r o v e d an d ne w ge ne ra t i o n st o ra ge te c h n o l o g i es.

• T h i n f i l m P V s ys te ms f o r p o w e r ap p l i c a t i o n s: E x p a ns i o n o f f a c i l i t i es f o r R & D o n l o w c os t an d h i g h e f f i c i e n c y t h i n f i l m p r o d u c ts; e x pa ns i o n o f e x i s t i n g c ha ra c te r isa t i o n an d tes t i n g ca pa b i l i t i es; an d R & D t o o p t i m i se m a n u f a c t u r i n g te c h n o l o g i es.

• C SP s ys te ms f o r p o w e r an d t he r m a l ap p l i ca t i o ns: O p t i m i se re ce i v e r s ys te m te c h n o l o g i es f o r p r o d u c ts an d m a n u f a c t u r i n g (cent ra l re ce i v e rs); e x pa ns i o n o f e x i s t i n g s ys te m des i g n, s i m u l a t i o n an d o p t i m i sa t i o n ca pa b i l i t i es, i n c l u d i n g r e ce i v e r s t r u c t u r e an d t ra c k i n g s ys te ms, an d d r y an d h y b r i d c o o l i n g i n t he p o w e r b l o c k; de v e l o p m e n t o f ap p r o p r i a te ed u ca t i o n an d t ra i n i n g p r o g r a m m es; an d esta b l i s h i n g R & D f a c i l i t i es f o r i m p r o v e d an d ne w ge ne ra t i o n abs o r be r an d st o ra ge te c h n o l o g i es.

• T h e r m a l ap p l i c a t i o n s: S ys te m o p t i m i sa t i o n resea r c h p r o j e c ts f o r spec i f i c ap p l i ca t i o ns, espec i a l l y f o r p r o cess hea t w h e r e a s i g n i f i c a n t c o n t r i b u t i o n ca n be m a de.

O t h e r aspec ts t o c o ns i d e r i n c l u de: so l a r r esea r c h pa r k s; ce n t res o f e x ce l l e n ce; u n i v e r s i t y c ha i rs; spec i f i c o u t-c o n t ra c te d p r o j e c ts b y D S T an d D o E; an d ge ne ra l ed u ca t i o n an d t ra i n i n g p r o g ra m m es.

http://www.sandia.gov/

4. Review of the R & D strategiesT h e p r o p ose d f i v e an d te n y ea r ac t i v i t i es w e r e re v i e w e d an d be n c h m a r k e d aga i ns t t he o u t c o mes o f t w o w o r k s h o ps; t he f i r s t a C SP W o r k s h o p he l d o n 1 1 D e c e m be r 2009, an d a sec o n d w o r k s h o p o n 1 9 F e b r ua r y 20 10 w h e r e sta ke h o l d e rs i n t he so l a r ene r g y f i e l d (go ve r n m e n t, i n d us t r y an d t he resea r c h i n s t i t u t i o ns) he l d a st ra te g i c c o n v e rsa t i o n ab o u t t h e p r o p ose d S E T R M . T h ese w o r k s h o ps a re d o c u me n te d i n sepa ra te re p o r ts.

4.1. Outcomes of the CS P Workshop: 11 December 2009T h e f o c us o f t h i s w o r k s h o p ca l l e d “So l a r E n e r g y I n d u s t r y i n S o u t h A f r i c a” w a s t o i d e n t i f y a ‘ r oa d m a p’ f o r so la r ene r g y resea r c h an d issues t o be ad d ressed t o f a c i l i t a te t he te c h n o l o g y r o l l-o u t o f so l a r ene r g y p o w e r, w i t h a f o c us o n c o n ce n t ra te d so la r p o w e r (CSP). T h e w o r k s h o p pa r t i c i p a n ts i d e n t i f i e d a l i s t o f te n so la r ene r g y resea r c h p r i o r i t i es f o r t he f o r eseeab le f u t u r e:

1 . E s ta b l i s h a S o l a r S c i e n ce an d Te c h n o l o g y F o r u m t o c o o r d i n a te na t i o na l resea r c h an d de v e l o p m e n t ac t i v i t i es an d a ls o ne t w o r k/co l l a b o ra te w i t h na t i o na l r esea r c h p r o g r a m m es suc h as H y S A an d i n t e r na t i o na l p r o g r a m m es suc h as S o l a rP A C E S.

2. D e v e l o p a S o l a r R es o u r ce M a p f o r S o u t h A f r i c a w i t h d i f f e re n t r es o l u t i o n s de pe n de n t o n t he a rea.

3. C SP Po te n t i a l S t u d y – t o de f i n e a p r o cess t o ge t g ua ra n tee d ac cess t o t he g r i d, na me l y i n c l u de g r i d-access, t o p o g ra p h y, so la r reso u r ce, w a te r reso u r ce, ec o l o g i c a l l y sens i t i v e a reas, l a n d a va i l a b i l i t y.

4. So l a r Pa r k s – ad v o ca te f o r t h e de v e l o p m e n t o f a “So l a r I n d u s t r y D e v e l o p m e n t P la n” w i t h t he D e p a r t m e n t o f T r a de an d I n d us t r y (DT I) (si m i l a r t o t he M o t o r I n d us t r y D e v e l o p m e n t P l a n [ M I D P]), t o st i m u l a te b o t h so la r p o w e r p l a n ts an d a so la r m a n u f a c t u r i n g i n d us t r y; an d t o i n c l u de st u d i es o n j o b c rea t i o n, ec o n o m i c de ve l o p me n t, sp i n-o f f s, a m o n gs t o t h e rs.

5. E ne r g y S t o r a ge - t he r m a l an d o t he r hea t t ra ns fe r f l u i d s.

6. H e l i os ta t F i e l d - st r u c t u re, s i m u l a t i o n an d des i g n so f t w a r e, m i r r o r s, c o n t r o l, o pe ra t i o n an d m a i n te na n ce.

7. N a t i o na l S o l a r Tes t an d D e m o ns t ra t i o n Fa c i l i t y - c o u l d be a l o n g s i de a C SP p l a n t.

8. C o o l i n g f o r C SP p l a n ts w i t h l ess w a te r (also w a te r use d f o r c lea n i n g o f m i r r o r s).

9. H i g h Te m pe ra t u r e H e a t-E x c h a n ge rs, i n c l u d i n g m a te r i a ls.

1 0. O t h e r A p p l i c a t i o ns o f C SP – t o ca r r y-o u t f eas i b i l i t y s t u d y o n desa l i na t i o n, so l a r c he m i s t r y, so la r hea t i n g an d c o o l i n g, a m o n gs t o t h e rs.

T h e ten o u t c o mes a re c o m pa r e d aga i ns t t he p r o p osed ac t i v i t i es l i s te d u n de r sec t i o ns 6.3. 1 an d 6.3.2 i n Ta b l e 33.

4.2. Outcomes of the SET R M Workshop: 19 February 2010T h e f o c us o f t he W o r k s h o p, a t te n de d b y re p resen ta t i v es f r o m g o v e r n m e n t, i n d us t r y an d t he resea r c h i n s t i t u t i o ns (see A p p e n d i x B), w a s t o en ga ge a st ra te g i c c o n v e rsa t i o n ab o u t t he p r o p ose d S o l a r E n e r g y Te c h n o l o g y R o a d ma p (SE T R M) f o r S o u t h A f r i c a, c o n ce n t ra t i n g o n w h i c h te c h n o l o g i es t he D e p a r t m e n t o f S c i e n ce an d Te c h n o l o g y (DS T) sh o u l d ta ke f o r w a r d f o r i n v es t m e n t, an d h o w t h i s sh o u l d be d o ne. T h e w o r k s h o p pa r t i c i p a n ts i d e n t i f i e d t he f o l l o w i n g p r i o r i t i es f o r resea r c h p r o j e c ts:

• P r o c u re a s ma l l C SP p l a n t i n c o n j u n c t i o n w i t h a so la r t he r m a l resea r c h f i e l d s ta t i o n, f o r t ra i n i n g / R & D / sh o w case p u r p oses.

• A d v a n ce h i g he r te m pe ra t u re (100-200ºC), n o n-t ra c k i n g so la r t h e r m a l c o l l e c t i n g s ys te ms f o r p r o cess hea t i n g an d c o o l i n g ap p l i c a t i o n s.

• I n i t i a te r esea r c h o n c o m p a c t l i n ea r F r esne l s ys te ms (C L FS).

• I n v es t i n r esea r c h o n st o ra ge o f so la r t he r m a l ene r g y an d o t he r re ne w a b l e ene r g y.

• I n v es t i n r esea r c h o n C SP p l a n ts’ p o w e r b l o c k s, t u r b i n es an d ge ne ra t o r s (opt i m i se d f o r sta r t-s t o p o pe ra t i o ns).

• I n v es t i n r esea r c h o n d r y-a i r/h y b r i d c o o l i n g f o r C SP p l a n ts, o r “d r y ” p o w e r c y c l es.

• E s ta b l i s h ap p r o p r i a te q ua l i t y assess me n t m e t h o ds an d stan da r ds f o r p h o t o v o l ta i c (PV) s ys te ms.

T h e se ve n o u t c o m es a re c o m p a re d aga i ns t t h e p r o p ose d ac t i v i t i es l i s te d u n de r sec t i o ns 6.3. 1 an d 6.3.2 i n Ta b l e 33.

Table : Comparison of S ET R M activities with the outcomes of the workshops

Focus Areas CS P Workshop Output SET R M Workshop Next Five Years Next Ten Years

11 December 2009Output

19 February 2010(Proposed SET R M) (Proposed SET R M)

S o l a r R eso u r ce A s sess me n t

2. S o l a r R es o u r ce M a p Pa r 6.3. 1 n o t e

P h o t o v o l t a i c S ys te ms 7. D e v e l o p m e n t o f q ua l i t y sta n da r ds an d assess me n t s ys te ms. R esea r c h o n c o n c en t r a t e d P V s ys te ms, w i t h t r a c k i n g

Pa r 6.3. 1 n o t e

Pa r 6.3. 1 b u l l e ts 1 , 2

Pa r 6.3.2 b u l l e ts 1 ,2

C o n ce n t r a t e d S o l a r P o w e r

3. C SP p o te n t i a l st u d y

4. S o l a r I n d u s t r y D e v e l P l a n

5 & 6 & 8 & 9. R & D o n st o r a ge, he l i o s t a t, hea t-e x c ha n ge r & C SP c o o l i n g s ys te ms

1 0. C SP f eas i b i l i t y st u d i es o n desa l i n a t i o n, so l a r c he m i s t r y

3. A d v a n ce t he R & D o n c o m pa c t l i n ea r F r es ne l s ys te ms

4. R esear c h o n ener g y st o ra ge tec h n o l o g y f o r re ne w a b l e an d o t he r ene r g y s ys te ms

5 & 6. R esea r c h o n C SP p l a n t ’s p o w e r b l o c k an d d r y-a i r/h y b r i d c o o l i n g s ys te ms

Pa r 6.3. 1 b u l l e ts 3, 4, 5 Pa r 6.3.2 b u l l e t 3 p l us ad d i t i o n a l n o t e

I n d us t r i a l S o l a r H e a t i n g an d C o o l i n g

1 0. F eas i b i l i t y st u d i es o n so l a r hea t i n g an d c o o l i n g ap p l i ca t i o ns

2. C o m m i ss i o n >80 ºC n o n-t r ac k i n g so l a r t he r m a l c o l l e c t i n g s ys te ms f o r p r o cess hea t i n g an d c o o l i n g

Pa r 6.3. 1 b u l l e ts 6, 7, 8 Pa r 6.3.2 b u l l e t 4

N a t i o na l c o o r d i na t i o n an d c o l l a b o r a t i v e de m o ns t r a t i o n f a c i l i t i es

1 . S o l a r S & T f o r u m

7. N a t i o n a l so l a r tes t & de m o f a c i l i t y

1 .P r o c u r e a <50 M W so l a r t he r m a l p l a n t f o r t r a i n i n g, R & D an d sho w case p u r p oses

Pa r 6.3.2 ad d i t i o na l n o t es

F r o m an e va l u a t i o n o f t he c o m pa r i s o ns o f t he v a r i o u s o u t c o m es o f t h e p r o p ose d S E T R M an d t he W o r k s h o ps i n Ta b le 33, f i v e de f i n i t i v e so la r te c h n o l o g y s ys te m f o c u s a reas ca n be i de n t i f i e d, na me l y:

1 . S o l a r R es o u r ce A s sess me n t;2. P h o t o v o l t a i c S ys te ms;3. C o n ce n t ra te d S o l a r P o w e r;4. I n d u s t r i a l S o l a r H e a t i n g an d C o o l i n g; an d5. N a t i o na l c o o r d i n a t i o n an d c o l l a b o r a t i v e de m o ns t ra t i o n f a c i l i t i es.

F o r p ra c t i c a l i m p l e me n ta t i o n o f t he S E T R M i t i s su g ges te d t ha t a st r u c t u re o r s t r u c t u r es a re c rea te d t o ac c o m m o da te t he v a r i o us ac t i v i t i es, as o u t l i n e d i n Ta b l e 33, w i t h i n t hese te c h n o l o g y s ys te m f o c us a reas.

6. R E F E R E NC ES

A b e l D , 2009. S o l a r w a te r hea t i n g p r o g r a m m a t i c C D M . So l a r W a t e r H e a t i n g c o n f e r e n ce, M i d r a n d, S o u t h A f r i c a.

A b e n g oa S o la r, 2008. S o la r p o w e r f o r a sus ta i na b l e

w o r l d : h t t p .A f r a n e O k ese, Y, 2009. D r a f t s t ra te g i c f r a m e w o r k an d

i m p l e me n ta t i o n p l a n f o r S o u t h A f r i c a n na t i o n a l so la r w a t e r hea t i n g: O v e ra l l re c o m m e n de d h i g h le v e l s t ra te g i c f r a m e w o r k. S o la r W a t e r H e a t i n g c o n f e r e n ce, M i d r a n d, S o u t h A f r i c a.

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Solar Energy Technology Roadmap of South Africa

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