Post on 27-Jul-2018
Fakulteit Ingenieurswese
Faculty of Engineering
Introduction and General Information
Solar Thermal Energy Research Group
Stellenbosch University
February 2013
Paul Gauché
STERG – Only formal CSP research group in SA*
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* At this time at a SA university
STERG in action at SolarPACES 2012
~ 60 Members in January 2013
From/at: SU, UCT, Wits, CSIR, UKZN, NMMU,
NWU, Eskom, Sasol, Germany, China, Holland, etc.
Primary grants: DST-NRF, Sasol, Eskom
Solar thermal history at SU
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Research and academic
committee representative
1980 - 1989 1990 - 1999 2000 – 2009 2010 -
SOLAR THERMAL ENERGY
RESEARCH GROUP
Solar resource station at SU Solar chimney research at SU commences
Dry cooling research at SU commences
Solar roof lab commissioned
National SANERI/DST
RE centre founded
First Parabolic Trough Research
SANERI/DST Solar
thermal spoke
& Hope project
Sasol researcher
STERG acceleration
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2010
7 – 15 people
2011
~ 30 people
2012
~ 45 people
2013 –
~ 60 people
SOLAR THERMAL ENERGY
RESEARCH GROUP
Solar resource station at SU
Solar roof lab expansion (with
tower, kiln, etc)
NRF solar thermal
spoke 2013 - 17
Sasol 40 m2
heliostat field
Eskom chair and
centre of excellence
STERG infrastructure & resources
• Staff: 7 (Eskom/Sasol researchers, administrative, engineering
and technical support)
• 1,000 m2 solar roof laboratory, staff office, workshop &
control room
• 18 m lattice tower (multi-use)
• 600 °C,1.5 m3 packed bed storage rig & 1,200 °C kiln
• Solar resource station with free web download (K&Z full
tracker and shadow ring)
• R400,000 Solar water heating test facility
• 25 kWe Eskom McDonnel Douglas Stirling Dish
• Key SW: TRNSYS, Matlab, Flownex, Fluent & open source.
• Primary Grants: DST/NRF solar thermal spoke, Sasol Sr
Researcher, Eskom Chair, SU Hope project, NRF THRIP.
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STERG R&D overview
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Italics: On-going R&D
System R&D
Systems analysis | Plant thermodynamic models |
Techno-economic analysis | Plant concepts & design
Dry Cooling
Dry | Hybrid |
Diurnal etc
Heat Transfer
Fluids & Storage
CO2 | Air | NaK | Salt |
Rock | Metal PCM
Heliostats &
Receivers
Control | Drives | Optics
| Field | Heat Transfer
Solar Resource
R&D
Satellite | Ground
SUNSTEL (SU Solar Thermal Electricity Project)
(Primary technologies: SUNSPOT, LFR, Dish) Other
Better SWH |
Coal power
augmentation
| other…
STERG – Solar Thermal Energy Research Group
Physical, Social, Mathematical, Political,
Statistical Sciences, Geography, Philosophy, etc. Engineering (ME, EE, others)
SUNSPOT – primary technology
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11+ Projects from distribution to system to
components focused on SUNSPOT
The idea in concept: Helio400
• Construction of a heliostat field and tower
• 100% developed at SU
• 100% commodity items available in SA
• Smart (learning) system enables minimal site prep
and max cost reduction
• Protected IP
• Completed and on-going R&D
• Simple, robust and scalable
• Baseline components
• ~20m lattice tower designed for flex use (similar
to our suntower)
• Heliostat modules consisting of steel, mirrors,
controllers and drives (prototyped)
• Heliostat field control system (prototyped)
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100% locally developed heliostat field • Local IP and design + expired prior art/common knowledge
• Philosophy of cheap = Smart learning system + minimal site prep
• Scalable (designed for 5MWe), re-deployable/mobile
• First revision of a product roadmap (blend of off the shelf and new ideas)
400 m2 mirror heliostat
field using SU designed
heliostat modules and
system control
<1 Ha land
(dual use with
grazing)
23 m lattice tower
Basic calorimeter
receiver (swappable
for high tech
experiments)
Steps toward the idea
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2010 2011 2012 2013 2014 –
1000 x
100 x
10 x
1 x 1 dumb heliostat
concept and pedestal
1 controlled heliostat
0.5m2
18 smart heliostats
with system control
& separate heliostat
optics design
20 smart heliostats
with system control
40.0m2 aperture
Funded by Sasol
100 - 400 smart heliostats
with system control
400.0m2 aperture
THIS PROPOSAL
18 m lattice tower
modular and reconfigurable
for multi-use
Here today
Sasol funded
~23 m lattice tower + receiver housing
modular and reconfigurable
for multi-use
~TRL 5
~TRL 6
~TRL 7
Helio18 Helio40 Helio400 Helio4000
CSP roadmap and resource
• Work by STERG and CRSES
• Contributors: Riaan Meyer, Tom Fluri, others
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Viable short term sites Viable long term sites
Prior work on SA CSP potential
• CSP potential has been investigated by Fluri (short term)
and Meyer & van Niekerk (longer term)
• Short term multi-constraint potential (500GWe+) vastly
exceeds current or future electricity needs
• This work extends previous work to explore full potential
of dispatchability
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Value and potential of CSP – P Gauche
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IRP Capacity IRP Electricity produced
Source: SA promulgated IRP2010 replotted from table
Results and analysis: Time plots
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8 January days
8 June days
Value and potential of CSP – P Gauche
Feasibility of peaking CSP plants in SA
• Objective
• Investigate the feasibility of utilising the peaking CSP plants in South Africa
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Cebo Silinga, MEng (Mechanical)
• Methodology
• Modelling of different
scenarios to obtain optimal
plant parameters
• Validity
• Competitive energy generation costs
• Guarantee of energy to the grid
• Rationale
• IRP 2010 – 2030 allocates 8
666 MW to (OCGT/CSGT),
which has low capacity factor
and high running costs
• CSP plant is able to deliver
guaranteed dispatchable
power to demand
Storage and Hybridisation in a solar plant
CSP system analysis and industrialisation
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Alan Brent, PhD, PrEng
Integrated analyses methods
Systems thinking
Institutional
arrangements
Policy interventions
Solar resource: Best satellite and ground data
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GeoSUN Africa will have exclusive rights to present the SolarGIS satellite derived solar data
base and other services of GeoModel Solar based in Slovakia.
www.geosun.co.za
Riaan Meyer
Solar assisted power generation (SAPG)
• preheating of boiler feedwater
• compliment extracted turbine
steam with solar heat
• efficient use of low to medium
temperature solar heat (less
than 250°C) for power
generation
Modelling of the SUNSPOT cycle and its rock bed thermal
energy storage system
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Lukas Heller, Dipl.-Ing.
Project:
• Building a software model of a rock bed
thermal energy storage (TES) system
• Simulations of a combined cycle plant
including TES system
• Sensitivity analyses for dependency on
plant and storage dimensions
• Study of the technical feasibility of the
SUNSPOT cycle and its components
Findings:
• Rock bed TES provides desirable energy
storage characteristics at low costs
• High dependency of electricity costs on
plant’s operating strategy
Research on solar power plant simulation with high
temperature heat transfer fluids will proceed on Ph.D. level.
Air-cooled steam condenser performance
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Michael Owen, MScEng
•Air-cooled steam condensers (ACCs) directly consume no
water during the cooling process and are therefore highly
suited for application in fully sustainable renewable energy
projects such as solar thermal power plants.
•The reflux condenser, or dephlegmator, component is
critical to the effective operation of an ACC.
•The steam-side operation and correct sizing of
dephlegmators is poorly understood.
•This study will attempt to provide information that can be
used to address the above mentioned issues.
•The steam-side operation of a novel hybrid (dry/wet)
dephlegmator concept has also been investigated and
recommendations made regarding a preferable configuration
for improved ACC performance.
Development of a Hybrid Pressurized Air Receiver
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Holger Kretzschmar, B Eng (mech), MSc Eng Candidate
• Ray-tracing and computational fluid dynamics (CFD)
modelling of the hybrid receiver concept
• Empirical validation using a medium flux concentrator
(1 kWth)
Heliostat Optics
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Willem Landman, MSc Candidate Editor note: Willem likely continuing on a PhD looking at industrialization optimization of heliostats
• Astigmatic Aberration Effects of Curved Heliostat Profiles
on Imaging
• Ray-Tracing, Surface Modelling and Optimization
Discrete Element Modelling of packed rock
beds for thermal storage applications
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Rick Nel (MSc candidate)
Actual rock bed Numerical rock bed
1. Develop discrete element models of packed
rock beds
2. Implement models to investigate various
aspects associated with such beds, which
are too impractical, impossible or expensive
to achieve through normal experimental
procedures
2.1 Investigate the potential of self-supporting tunnel
networks
2.2 Conduct preliminary mechanical and thermal
stresses analysis’
2.3 Construct geometric models suitable for CFD
studies
2.4 Investigate the effect of the packing style on
the local and global rock orientations
Contact forces before
thermal cycling
Contact forces after
thermal cycling
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findings, plots, photo’s, etc. of your work.
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Development of a low cost heliostat drive
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Chris Price, MSc Candidate
An experimental rig used to test the feasibility
of friction drives for heliostat use.
SUNSTEL – Monte Carlo Ray Tracer for Central
Receiver Plants
• Development of a Monte
Carlo ray tracer designed
for CSP applications
• Flux imaging and code
verification done
experimentally using flux
sensor and CMOS camera
• Coded based in C++ and
designed for speed and
extendability
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Sebastian-James Bode (BSc Mech Eng)