PVTRIN Training course - Worksheet iii
CONTENTS
CONTENTS
Part I HANDBOOK EXERCISES AND
SOLUTIONS 2
1. SOLAR BASICS 2
1.1. Solar Photovoltaic (PV) Energy 2
1.2. PV system 5
1.3. PV technologies 5
1.4. Types of PV systems and
applications 5
1.5. Benefits of PV technology 5
2. DESIGN PRINCIPLES 6
2.1. Case studies 6
2.2. Multiple Choice Questions 8
2.3. True–False questions 10
2.4. More Practice 11
3. BAPV and BIPV 14
3.1. Mounting and building integration
options 14
3.2. BIPV and BAPV on roofs 14
3.3. BIPV and BAPV on façades 15
3.4. Glass roofs, shading systems and
other applications 16
3.5. Design parameters and
performance factors 16
4. INSTALLATION – SITEWORK 18
5. CASE STUDIES – BEST PRACTICES 20
6. EXAMPLE INSTALLATION OF A SMALL
SCALE PV ON A BUILDING 21
7. MAINTENANCE AND
TROUBLESHOOTING 24
7.1. Maintenance plan 24
7.2. Typical mistakes and failures 24
7.3. Diagnostic procedures 25
7.4. Documentation to the customer 25
7.5. Maintenance checklist 25
8. QUALITY MANAGEMENT AND
CUSTOMER CARE 26
Part II FURTHER PRACTICE: MORE
EXERCISES AND ACTIVITIES 28
1. SOLAR BASICS 28
1.1. Solar Photovoltaic (PV) Energy 28
1.2. PV system 30
PVTRIN Training course - Trainers Worksheet iv
1.3. PV technologies 30
1.4. Type of PV systems and application 31
1.5. Benefits of PV technology 32
2. DESIGN PRINCIPLES 33
2.1. Site Survey 33
2.2. System Sizing and Design 33
2.3. Economics and Environmental
Issues 41
2.4. Standards and regulations 42
OPEN QUESTIONS 43
3. BAPV and BIPV 44
3.1. Mounting and building integration
options 44
3.2. BIPV and BAPV on roofs 44
3.3. BIPV and BAPV on façades 45
3.4. Glass roofs, shading systems and
other applications 45
3.5. Design Parameters and
Performance Factors 46
4. INSTALLATION – SITEWORK 48
4.1. Working safely with PV 48
4.2. Installation plan 49
4.3. Electrical components installation 49
4.4. Equipment Installation 50
4.5. Mechanical Components Installation 52
4.6. Grid-connected PV Systems 53
4.7. Stand-alone PV System 53
4.8. Mounting system and building
installation. 54
4.9. Completing the PV installation 54
5. CASE STUDIES – BEST PRACTICES 55
6. EXAMPLE INSTALLATION OF A SMALL
SCALE PV ON A BUILDING 56
7. MAINTENANCE AND
TROUBLESHOOTING 57
7.1. Maintenance plan 57
7.2. Typical mistakes and failures 57
7.3. Diagnostic procedures 59
7.4. Documentation to the customer 59
7.5. Maintenance checklist 59
8. QUALITY MANAGEMENT AND
CUSTOMER CARE 59
LIST OF TABLES 60
LIST OF FIGURES 60
PVTRIN Training course - Trainers Worksheet 2
Part I HANDBOOK EXERCISES
AND SOLUTIONS
1. SOLAR BASICS
1.1. Solar Photovoltaic (PV) Energy
1. For the city of Chania (φ=35,3) calculate
the monthly average total solar radiation
on a tilted panel (β=10ο and β=55ο ) facing
south in December and in June. For the
calculations pick as representative the 10th
of each month. Which is the optimum tilt
(10ο or 55ο) if the PV system will operate
only in winter? The panel’s albedo is 0.25.
Use the values in TABLE 1.
Month
Average
monthly
Clearness
index (k)
Monthly
average total
solar radiation
on a horizontal
surface
(kWh/m2)
Number
of days
January 0,4 62 31
February 0,45 80 28
March 0,49 124 31
April 0,56 167 30
May 0,62 212 31
June 0,63 220 30
July 0,64 225 31
August 0,64 203 31
September 0,61 159 30
October 0,52 116 31
November 0,5 71 30
December 0,42 53 31
TABLE 1.
INDICATIVE MONTHLY VALUES
The Solar Declination, Solar Altitude Angle
and the Solar Hour Angle are shortly
presented below.
Solar declination (δ) is the angle between the
sun’s rays and a plane passing through the
equator illustrated in Figure i.
FIGURE 1. SOLAR DECLINATION, δ
The solar declination depends only on the
day of the year. The declination is also equal
to the latitude at which the sun is directly
overhead at solar noon on a given day. The
declination is positive when the sun is directly
overhead north of the equator (December 21
through June 21) and it is negative when the
sun is directly overhead south of the equator
(June 21 through December 21). The solar
declination, δ, can be calculated from the
equation:
δ= (23.45o)sin[360o (284 + n)/365]
Where n is the day number in the year,
January 1 = 1.
The Solar Hour Angle measures the position
of the sun relative to solar noon at a given
time at any given location on the earth. The
hour angle, w, is zero when the sun is directly
overhead (local solar noon). It is negative
before local solar noon and is positive in the
afternoon. The hour angle changes by 15o
each hour or 1o in 4 minutes. The variation of
the solar hour angle with local solar time is
summarized in table ii.
PVTRIN Training course - Trainers Worksheet 3
Part I HANDBOOK EXERCISES
AND SOLUTIONS
Solar time Hour angle ω ,
in degrees
6 hrs before solar noon -90
5 hrs before solar noon -75
4 hrs before solar noon -60
3 hrs before solar noon -45
2 hrs before solar noon -30
1 hr before solar noon -15
solar noon 0
1 hr after solar noon 15
2 hrs after solar noon 30
3 hrs after solar noon 45
4 hrs after solar noon 60
5 hrs after solar noon 75
6 hrs after solar noon 90
TABLE 2.
HOUR ANGLE ω
The Solar Altitude Angle (FIGURE 2) is the
angle between the sun’s rays and a horizontal
plane.
FIGURE 2.
SOLAR ALTITUDE ANGLE, a
When the sun is just rising or setting, the
altitude angle is zero.
When the sun is directly overhead, the
altitude angle is 90o. The solar altitude angle,
a, can be calculated for any location and a
time from the latitude, L, solar declination, d,
and solar hour angle, w, using the following
equation:
sin a = sin φ sin δ + cos φ cos d cosω
In our calculation, the values for the sunset
hour angle are required. The solar altitude
angle, a , will be zero for sunset, so an
equation for sunset hour angles can be found
by setting a equal to zero in equation above
and solving for ω.
For the calculations the minimum of these
values is selected:
ωss = min {cos -1(-tan(φ ) tan(δ)), cos -1(-
tan(φ-β) tan(δ))}
Solution
� For December 10th which is the 344th
day of the year
δ= (23.45o)sin[360o (284 + 344)/365] =-23.050
then the value of ωss is estimated.
ωss = min {cos -1(-tan(35.3) tan(-23.05)), cos -
1(-tan(35.3-10) tan(-23.05))}
ωss = min (72.47 , 78.40)
so the value of 72.48 is selected.
Rb (geometric factor) is the ratio of the direct
solar radiation on a tilted surface to the
direct solar radiation on a horizontal surface.
Rb is calculated by the following equation.
Rb =
so for the given data
PVTRIN Training course - Trainers Worksheet 4
Rb =
=
= 1.35
According to the equation of Collares-Pereira
and Rabl the ratio of the monthly average
diffuse solar radiation (Hd) to the monthly
average total solar radiation, as a function of
ωss and kt (Clearness index),is provided by
the following equation:
Hd/H = 0.775+0.00653(ωss-90)-[0.505+
0.00455 . (ωss -90)] . cos(115 . kt – 103)
so for the data given
Hd/H = 0.775+0.00653(72.78 - 90) - [0.505+
0.00455 . (72.48 - 90)] . cos(115 . 0.42 – 103)
=0.42
Furthermore, the monthly average total solar
radiation on a tilted surface (HT) to the total
solar radiation on a horizontal surface (H) is
provided by the following equation:
HT/H =
where ρ = panel’s albedo
⇒ HT/H =
⇒
HT/H =1.2 ⇒
HT = 1.2 . 53=63.88kWh/m2
The procedure then is repeated for a tilt of
55o of December and for both angles of June.
The results are summarized in the table
below
December 10th
June 10th
β=10ο β=55
ο β=10
ο β=55
ο
n 344 344 161 161
δ -23.05 -23.05 23.01 23.01
ωss
min(72.47
, 78.40)
=72.48
min(72.47
, 98.76)
=72.48
min(107.4
9, 101.57)
=101.57
min(107.4
9, 81.26)
=81.26
Rb 1.35 2.31 0.98 0.63
Hd/H 0.42 0.41 0.37 0.32
HT/H 1.20 1.73 0.98 0.73
HΤ
63.88
kWh/m2
91.73
kWh/m2
216.76
kWh/m2
161.3
kWh/m2
TABLE 3.
RESULTS OF EXERCISE 1
2. Which of the following irradiance
parameter is the most important when
calculating the PV system power output:
a) The Direct Normal Irradiance (DNI)
b) The Diffuse Irradiance (DIF)
c) The Albeldo Irradiance
d) The Global Horizontal Irradiance (GHI)
e) The Global In-Plane Irradiance
3. A PV cell is made of :
a) A conductor material
b) An insulator material
c) A semi-conductor material
4. What is the principal role of the inverter in
a PV system:
a) To prevent the batteries from
overcharging and discharging
b) To convert DC power generated by
PV modules to AC power
PVTRIN Training course - Trainers Worksheet 5
Part I HANDBOOK EXERCISES
AND SOLUTIONS
1.2. PV system
1. Which material is not used as an
encapsulant in a PV module?
a) PVB
b) PVC
c) EVA
2. Usually, the module producers guarantee
a power output of 80 % of the Wp after:
a) 10 to 15 years
b) 20 to 25 years
c) 25 to 30 years
1.3. PV technologies
1. Which cell technology is not part of the
first generation?
a) Cadmium Telluride solar cells
b) Mono crystalline silicon solar cells
c) Ribbon crystalline solar cells
2. What are the common characteristics of a
first generation solar cell?
a) 22.5 cm² and 4.5 Wp
b) 1.7 m² and 250 Wp
c) 20 m² and 3000 Wp
3. A thin-film module is generally smaller
than a crystalline silicon module.
a) True
b) False
4. Which technology has achieved the
highest efficiency in laboratory among the
thin-film technologies?
a) a-Si
b) a-Si/µc-Si
c) CIGS
d) CdTe
1.4. Types of PV systems and
applications
1. A grid-connected installation consists of
three components:
a) Generator, storage battery and power
supply.
b) Generator, converter and power
supply.
c) Generator, converter and storage
battery.
2. Off-frid PV systems are always small home
systems.
a) True
b) False
1.5. Benefits of PV technology
1. PV will never produce an important part
of the final European electricity
consumption because there are not
enough roofs available.
a) True
b) False
PVTRIN Training course - Trainers Worksheet 6
2. DESIGN PRINCIPLES
2.1. Case studies
Case Study 1
Sizing a 24VDC system voltage home
i. Loads, appliances and daily energy
requirements
TABLE 4. APPLIANCES AND DAILY ENERGY REQUIREMENTS
Loads and
Appliances
Power
rating of
appliances
(W)
Total
power
required
(W)
hrs of
use/d
ay (h)
Daily
energy
require-
ment (Wh)
Fluorescent
lamps
12W 60W (5
lamps)
3 180Wh
TV 100W 100W 1.5 150Wh
Microwave 640W 640W 0.5 320Wh
Refrigerator 80W 80W 3 240Wh
Lighting
outside
50W 50W 1 50Wh
TOTAL 930W 940Wh
The house roof has an inclination of 50° and
is orientated 60° southwest. The system is
designed for January and a 3-day storage
capacity is foreseen.
ii. Module sizing (see also chapter 2.2.8)
G = 5.0 PSH
nSYS = 0.6
E =940Wh daily energy requirement.
Hence, the minimum system size is 314 Wp.
iii. Sizing the battery (see also chapter 2.2.8)
V = 24VDC system voltage.
A = 3 days
E = 940Wh
T = 0.5
ninv = 0.9
ncable = 0.97
The minimum required battery capacity, Ah
For a 24VDC home system, 2 batteries with
24V/150Ah connected in parallel will be
chosen for a total of 24V/300Ah.
iv. Inverter
The system requires an inverter, as there are
only AC appliances in the house. The total
power required for AC appliances is 940W so
a 1,500W inverter with 24VDC input will be
recommended.
v. Wiring
In the case where the cable length is 8m,
made of copper and the drop voltage is 10%:
This result will be rounded to the next
standard value of 6 mm2.
The standard cross-section sizes are 2.5mm2;
4mm2; 6mm2; 8 mm2; 10 mm2; 12mm2; 14
mm2 ; 16 mm2; 18 mm2; 20 mm2; 22 mm2; 24;
26 mm2; 28 mm2; 30 mm2; 32 mm2.
PVTRIN Training course - Trainers Worksheet 7
Part I HANDBOOK EXERCISES
AND SOLUTIONS
An 80Wp mono-crystalline PV module of
about 12VDC (a nominal voltage rate of 12V)
with a nominal current of 4.5A is selected.
If we divide 314 by 80, we have 3.9, so 4
modules will be connected in series-parallel.
This means that the 2 modules are connected
in series and the 2 strings are connected in
parallel. The total voltage is 2 x 12 V = 24VDC
and the current is 4.5A x 2 =9.0A.
The current produced by the module
determines the charge controller. In this case
it is 9A. The charge controller has a minimum
of 9A. We can choose a greater one (15A) in
case of any foreseen expansion.
Case Study 2
Sizing a 5.5kWp PV system on a sloping roof
(length 9.0 m, and width 5.0 m).
TABLE 5. PV -MODULE CHARACTERISTICS
1.550m x 0.968m = 1.500m2 for 230 Wp. This
is equivalent to 6.5 m2 /kWp
i. Roof size
5.5kWp x 6.5 m2/kWp =35.75m2
Total modules: 5,500Wp/230Wp = 23.9 thus
24 modules should be consider for total
power output of 24 x 230 W= 5,520Wp
Modules should be checked, if laid out on
portrait format or landscape format, which
will depend on the length and the width of
the roof.
ii. Check if the module fits the roof
- In portrait format
Roof length
=
9.0m = 9.35
and Module
width
0.962m
Roof width
=
5.0m
= 3.23 Module
length
1.550m
The above calculation leads to a total of 9 x 3
= 27 modules; the maximum number of
modules laid in portrait that could fit onto
the roof is 27 (9 modules and 3 strings or
opposite); more than enough space for the
24 modules.
- In landscape format
-
-
-
5 x 5 is approximately 25, so maximum 25 (5
modules and 5 strings) modules can also fit in
landscape format.
The modules can be laid in both formats, but
it is better to choose the format in which
most modules may be laid out, so that the
system can be extended in the future. The
portrait format is therefore selected.
iii. Checking the module voltage
Voltage temperature coefficient: - 0.35% x
Voc/°C= -0.0035 x 35.8 = - 0.125V/°C
VMPP – 25°C = 29.8V
VMPP – 10°C = 29.8 + 15x 0.125 = 31.67V
VMPP -70°C = 29.8 – 45 x 0
Voc -10°C = 35.8 + 15 x 0.125 = 37.67 V
Parameter Value
Maximum power Pmax 230
Voltage at Max. power VMPp 29.8V
Current at Max.power IMP 7.71A
Open Circuit Voltage VOC 35.8V
Sort Circuit Current ISC 8.34V
Max. System Voltage 1000V
Temperature coefficient
Voltage (VOC) -0.35%/oC
Current (ISC) 0.060%/oC
Length x Width x Depth mm 1,550x962x40
Weight kg 18.5
PVTRIN Training course - Trainers Worksheet 8
iv. Inverter selection
Inverter nominal power is between 90% and
100% of (array) this is between 90% x 5,520=
4,968W and 5,520W (this range is chosen
because in case of good sunny days with
radiation at the STC or over the STC, the
inverter should not be undersized), so 4
inverters (TABLE 6) can be chosen for a string-
inverter concept.
TABLE 6.
INVERTER CHARACTERISTICS
v. Module configuration
Maximum number of modules on a string:
Minimum number of modules on a string:
Therefore the maximum number of modules
is 8 on a string and the minimum is 4.
vi. Array configuration and inverter
compatibility
4 strings of 6 modules with 1 inverter on each
string, will be implemented. The voltage
compatibility has to be checked.
VMPP -70°C = 6 x 24.18V = 145V, this is
acceptable as it is above the lower voltage of
the MPP-range (96V) VMPP
VMPP – 10°C = 6 x 31.67V = 190 V, this is also
acceptable as it is below the upper limit of
the MPP voltage range (320V) VMPP
Voc -10°C = 6 x 37.67= 226V, this is below the
maximum inverter input voltage (400V) also
acceptable Voc
The current at the MPP of the module is
7.71A, which is acceptable and below the
maximal input current of the inverter (12.6
A).
This is a string-inverter concept. The array
has a total wattage of 5,520kWp which
consists of 24 modules, each with 230 Wp.
The array is configured in 4 strings of 6
modules.
2.2. Multiple Choice Questions
1. What is meant by the Standard Test
Condition (STC)
a) Radiation: 1,000W/m2, temperature:
25°C, and Air Mass: 1.5
b) Radiation: 1,000W/m2, temperature:
20°C, and Air Mass: 1.5
c) Radiation: 1,024W/m2, temperature:
25°C, and Air Mass: 1.5
d) Radiation: 1,000W/m2, temperature:
18°C, and Air Mass: 1.0
2. If a PV cell produces 0.5 V, then four PV
cells connected in series will produce:
a) 2.0 V
b) 0.5 V
c) 2.5 V
d) 1.0 V
3. The total power across four PV cells of
0.5V connected in series when Acell = 1A
is:
a) 2.0 W
b) 0.5 W
c) 2.5 W
d) 1.0 W
Parameter Units Value
Max DC power W 1,400
Max DC voltage V 400
V-voltage range, MPPT V 96-320V
Max Input Current A 12.6
PVTRIN Training course - Trainers Worksheet 9
Part I HANDBOOK EXERCISES
AND SOLUTIONS
4. If a PV cell delivers a current of 0.6A and
there are three PV cells in parallel then
the current flowing through the load is:
a) 2.0 A
b) 0.6 A
c) 1.8 A
d) 1.0 A
5. The total power across three PV cells of
0.5V connected in parallel when Icell = 0.6
A is:
a) 2.0 W
b) 0.9 W
c) 0.3 W
d) 1.0 W
6. If 24 PV cells (0.5V) are connected in series
and parallel (6 cells and 4 rows), the total
voltage across the load is:
a) 2.0 V
b) 2.4 V
c) 12.0 V
d) 3.0 V
7. If the height of an obstacle is 3m the
minimum distance (Lmin) so that the PV
will not be shaded is:
a) 4.0 m
b) 6.0 m
c) 3.0 m
d) 1.0 m
8. “Increase in temperature leads to an
increase of n VOC resulting to increased cell
output”.
a) The statement is right
b) The statement is wrong
c) VOC does not depend on temperature
9. The efficiency of a PV cell may be
improved by:
a) adjusting the light facing angle all day
b) placing colored acetates on the cell
c) cooling the cell
d) changing its direction to north
10. Solar PV systems can be:
a) connected to the power grid
b) used to sell power to the grid
c) a stand-alone source of electricity
d) all answers a, b, c
11. In a series connection:
a) the positive terminal is connected to
the positive terminal
b) the negative terminal is connected to
the negative terminal
c) the positive terminal is connected to
the negative terminal
d) all the other answers
12. A stand-alone PV system can provide
electricity when no sunlight is present
with:
a) batteries
b) inverter
c) a battery charge controller
d) a and c
13. An inverter is required on a PV system if:
a) batteries are used
b) DC power is needed
c) AC power is needed
d) if the load is very large
14. If a PV system is tied into the electric
utility grid:
a) it does not have to use batteries
b) it needs batteries
c) no inverter is required
d) it cannot provide AC
15. The available surface area of a building is
108m2 (length=12.0m and width =9.0m),
and the area required by a panel is
length=1.64m and width =0.98m. If 55 PVs
are to be installed the optimum layout will
be:
PVTRIN Training course - Trainers Worksheet 10
a) landscape format
b) portrait format
c) there is no difference
d) neither format is appropriate
16. Wh-efficiency is always less than Ah-
efficiency in a battery.
a) True
b) False
c) We cannot know
17. A 100 W refrigerator can operate using a
150 W inverter without any problems.
a) True
b) False
c) We cannot know
18. A 24V back-up power system is supplied
via a single, 4mm2 solar cable, 15m long,
from a 200 W module. Is the cross-section
sufficient?
a) Yes
b) No
c) We cannot know
19. To improve the efficiency of the whole
system as of the planning procedure, the
designer should?
a) Install the modules in a way that they
will be well ventilated
b) Keep the cables as long as possible
c) Keep the tilt of the panels less than
15°
d) None of the other answers
20. A string concept with 8 inverters is
planned for the PV system with 12kWp.
What DC output should each inverter
have? Between…
a) 1.35 and 1.5 kW
b) 0.67 and 1.42 kW
c) 1.35 and 1.42 kW
d) None of the other answers
2.3. True–False questions
1. A Tracking system which follows the sun’s
daily migration can boost production by
up to 8%.
a) True
b) False
2. If half of a cell is shaded, the reduction in
output is the same as when even half a
row is shaded.
a) True
b) False
3. The maximum voltage occurs when there
is a break in the circuit.
a) True
b) False
4. Deep discharge improves the life
expectancy of a Pb-acid battery.
a) True
b) False
5. Temporal overcharge of a battery
improves the homogeneous of the
catalyst.
a) True
b) False
6. When sizing the cables, the permitted
current rating of the cable should be at
least equal or greater than the trigger
current of the string fuse.
a) True
b) False
7. The efficiency of string inverters range
from 50-60%.
a) True
b) False
PVTRIN Training course - Trainers Worksheet 11
Part I HANDBOOK EXERCISES
AND SOLUTIONS
8. The cost of the panels in about 70-80% of
the cost of the total system.
a) True
b) False
9. A safety distance of 0.10m between the
PV plant and all parts of the lightning
protection system has to be maintained.
a) True
b) False
10. The lifetime of the system is 10-15 years.
a) True
b) False
11. The material of which the PV cells are
made is toxic and hard to be found on
Earth.
a) True, in most of the cases
b) False, in most of the cases
12. Αll available online software applications
for PV system dimensioning provide
accurate calculations and reliable data.
a) True
b) False
13. The most expensive components of an
autonomous PV system are the batteries.
a) True
b) False
14. A rough estimation of the average value of
a PV system is approximately 8,000
€/kWp.
a) True
b) False
15. An approximate required surface can be
estimated, bearing in mind that: 10m2 =
1kWp
a) True
b) False
2.4. More Practice
1. A PV system uses 720 silicon PV cells
connected in an array which supplies up to
120 V.
1i.How many PV cells are connected in series
if 120 V are needed and one cell delivers
0.5 V?
a) 240
b) 120
c) 360
d) 60
1ii. What is the number of the rows
connected in parallel?
a) 2
b) 6
c) 4
d) 3
1.iii When the light intensity is 1,000 W/m2,
the total power output from the PV array
is 360W. What is the energy efficiency of
the PV cells? Each PV cell is a square
measuring 118mm by 118mm.
a) The energy efficiency of the cells is
3.0%
b) The energy efficiency of the cells is
2.8%
c) The energy efficiency of the cells is
3.6%
d) The energy efficiency of the cells is
4.8%
1iv. What type of silicon PV material are the
PV cells made from?
a) a-Si
b) poly-Si
c) mono-Si
2. Which type of charge controller is the
most appropriate for a PV system with 30
PVTRIN Training course - Trainers Worksheet 12
modules and a total power of 47Wp
connected to a 24V battery? The modules
are connected via 15 branches of 2 panels
per series and the maximum voltage of
each module is 17V. Take into account
that 6 lamps each of 60W and a CD player
of 160W will be in operation at the same
time.
a) A 24V – 65A charge controller
b) A 12V – 65A charge controller
c) A 24V – 45A charge controller
d) A 1V – 45Acharge controller
3. 130 kWh of energy are required to
manufacture 1 m² Poly-Si module. How
long will it take for this module to
generate an equivalent amount of energy,
given that solar irradiation in Greece is
1,350 kWh / (m² x yr)?
a) the energy payback of the PV system is
approximately 8 years.
b) the energy payback of the PV system is
approximately 6 years.
c) the energy payback of the PV system is
approximately 1.5 years.
d) the energy payback of the PV system is
approximately 4.5 years.
4. Briefly explain how PV panel efficiency is
influenced by temperature variations.
a) Temperature increase leads to a
reduction in Voc, resulting to reduced
efficiency
b) Temperature increase leads to a
reduction in Icc, resulting to reduced efficiency
c) Temperature increase leads to a
increment in Voc, resulting to increment
efficiency
d) Temperature increase leads to a
increment in Icc,, resulting to increment
efficiency
5. What is the optimum panel inclination for
a panel sited in Crete (φ=35.16°)?
a) φ= 35,16ο
b) φ= 55,16ο
c) φ= 15,16ο
d) φ= 60,00ο
6. How does an inverter work?
a) it converts AC voltage of the modules
to a higher value of AC voltage
b) it converts DC voltage of the modules
to AC voltage of the grid
c) it converts DC voltage of the modules
to a higher value of DC voltage
d) it converts AC voltage of the modules
to DC voltage of the grid
e) it converts AC voltage of the modules
to a higher value of AC voltage
7. Name 3 of the most common failures
where a PV system may lose energy.
Explain the reason for these losses
a) Shading (reduced irradiance on the
panel)
b) temperature decrease (reduced Impp)
c) temperature increase (reduced Voc)
d) fault orientation (reduced irradiance
on the panel)
e) short wiring (increased resistance)
8. What is the role of a blocking diode?
a) Blocking diodes protect the battery
when there is no light
b) Blocking diodes break the electrical
circuit if too much current is present
c) Blocking diodes search for the best
operating point of a module
PVTRIN Training course - Trainers Worksheet 13
Part I HANDBOOK EXERCISES
AND SOLUTIONS
d) Blocking diodes connect the frame of
an electrical device to the ground
9. What are the main requirements of a
stand-alone inverter?
a) low overload capability for switch-on and
starting sequences,
b) intolerance against battery voltage
fluctuations,
c) very good conversion efficiency, even
in partial load range,
d) one-directional operation
e) all the other answers
10. Which is the part of the PV system that
ensures max output power from the PV
module?
a) MPP Tracker
b) Blocking diode
c) Bypass Diode
d) Fuse
11. Under which circumstances a PV system
could cause environmental damage?
a) PV system are in general harmful for
the environment
b) There is no way that a PV system can
cause damage to the environment
c) Release of hazardous gasses in case of
a fire breaking out in a system
d) In case it is sited over an aquifer
12. Why should the PV systems be recycled?
Which is the main reason?
a) gain some money from selling raw
materials
b) potentially harmful materials are not
released into the environment
c) to avoid unnecessary aesthetical
impacts of useless systems
13. Name 3 parameters on which a PV
system’s energy payback time is
depending on.
a) cell technology
b) the colour of the wiring
c) type of encapsulation
d) line with the current fashion
e) frame and array support
PVTRIN Training course - Trainers Worksheet 14
3. BAPV and BIPV
3.1. Mounting and building
integration options
1. BAPV and BIPV are PV modules installed in
buildings exclusively as the principal
energy source.
a) True
b) False
2. Which is the main difference between
BAPV and BIPV?
a) BAPV can be installed only on roofs,
while BIPV can be installed on roofs,
façades, shelters and others
b) BAPV are used only as additional
energy source, while BIPV are used
both as additional and principal energy
source
c) BAPV are fixed over the existing
elements of building’s envelope, while
BIPV are photovoltaic materials used
instead of conventional building
materials
3. Where can BIPV and BAPV be installed?
a) Only in dwellings
b) In all type of buildings and in urban
structures as bus shelters
c) Only in industrial and dwelling
buildings
4. Building integration (BIPV) means that:
a) The modules serve an energy and
architectural purpose and also
substitute certain elements of the
building construction
b) The modules serve an aesthetic and
architectural purpose and also
substitute certain elements of the
building construction
c) The modules serve an energy and
architectural purpose, but do not
substitute any of the elements of the
building construction.
5. There are three key components of a grid-
connected system. Choose the right ones.
a) The façade of the building
b) The PV modules
c) The inverter
d) The roof
e) The current meter
f) The public grid
g) The windows
3.2. BIPV and BAPV on roofs
1. Which parameters should be taken into
account when installing PV modules on
flat roofs? Choose the three correct
aspects from the list below.
a) The structure of the roof
b) The thickness of the thermal insulation
c) The orientation of the building
d) The type of modules
e) Roof elements such as chimneys,
skylights, etc.
2. What should be checked, according to the
building regulations, when PV modules are
installed on existing buildings?
a) The covering material of the roof
b) The load bearing capacity of the
structure
c) The insulation materials
3. We should take care of the water-proofing
membrane of the roof when installing PV
modules.
a) True
b) False
PVTRIN Training course - Trainers Worksheet 15
Part I HANDBOOK EXERCISES
AND SOLUTIONS
4. BAPV are more suitable for:
a) Installation on existing buildings
b) Installation on new buildings
c) Installation on flat roofs
5. Explain how the over-heating of PV
modules on pitched roofs could be
avoided?
a) Covering the whole roof
b) Using PV tiles
c) Ensuring 5-10cm between the PV
element and the roof covering
3.3. BIPV and BAPV on façades
1. PV modules can be fully integrated and
cover the entire façade?
a) True
b) False
2. PV modules can be fixed to balconies.
a) True
b) False
3. PV modules can be fixed as an additional
glass façade.
a) True
b) False
4. We should ensure air tightness between
the joints of BAPV on façades.
a) True
b) False
5. BAPV on façades are easier for
maintenance.
a) True
b) False
6. BAPV may act as an additional thermal
insulation of façades.
a) True
b) False
7. It is easier to ensure cooling of BAPV than
of BIPV.
a) True
b) False
8. BIPV provide better opportunities for
aesthetic architectural solutions.
a) True
b) False
9. What is the difference between a cold and
warm façade?
a) Warm façades face the south while
cold façades face the north.
b) Warm façades have additional thermal
insulation, which is thicker than on the
cold façades
c) Warm façades are façades where the
PV modules are integrated in the
structure of the façade, while cold
façades are façades where PV modules
are an additional element, like a
second “skin” of the building
10. We should take the weather into account
such as wind and hailstorms when fixing
the modules on the façades.
a) True
b) False
11. We should ensure air and water tightness
of joints between the modules of BIPV.
a) True
b) False
12. The installation of modules on a ground-
floor façade is highly recommendable.
a) True
b) False
PVTRIN Training course - Trainers Worksheet 16
3.4. Glass roofs, shading systems
and other applications
1. A glass roof of PV modules reduces the
heat load and creates more comfortable
conditions within the building.
a) True
b) False
2. Is the installation of PV modules possible
on shading devices
a) Yes, but it is not recommended
b) Yes, they are very appropriate
c) No
3. We can combine PV and solar thermal
functions.
a) True
b) False
4. PV modules can be integrated in sound
barriers, street lights, information
displays.
a) True
b) False
3.5. Design parameters and
performance factors
1. Name 3 factors which may affect the
efficiency of a PV system?
a) The amount of solar radiance on the
site
b) The type of building
c) The orientation and tilt of the modules
d) The grid connection
e) The behaviour of the occupants of the
building
f) The quality of the modules and inverter
2. In the following table, rate the tilt and
orientation of PV modules from 1 to 4 (1 –
the best orientation and tilt, 4- the worst).
Tilt
Orient
ation
0⁰
30⁰
60⁰
90⁰
East
1 2 3 4
South-
east
2 1 3 4
South
2 1 3 4
South-
west
2 1 3 4
West
1 2 3 4
3. We should take into account future
erection of new buildings around a
building where PV are to be installed.
a) True
b) False
PVTRIN Training course - Trainers Worksheet 17
Part I HANDBOOK EXERCISES
AND SOLUTIONS
4. When planning to install a BIPV/BAPV, we
should take into account satellite receivers
and sky lights on the roof.
a) True
b) False
5. We could avoid problems with shading
through dummy modules and by-passes.
a) True
b) False
6. Name 4 parameters which should be
taken into account during the planning
stage:
a) The accessibility of the roof
b) The accessibility of the façade
c) The load-bearing capacity of the
structure of the building
d) The number of open spaces of the
building (windows etc.)
e) The traffic
f) The load from snow, wind, ice and hail
7. Which is the appropriate tilt angle for PV
modules in regions with heavy snowfall?
a) At least 30⁰
b) At least 45⁰
c) At least 60⁰
8. The installer should avoid stepping on the
module.
a) True
b) False
9. The installation of a PV installation cabling
should be waterproof.
a) True
b) False
PVTRIN Training course - Trainers Worksheet 18
4. INSTALLATION – SITEWORK
1. Which is the main characteristic of PV
modules that makes them hazardous if
exposed to daylight?
a) PV modules generate DC electricity
which cannot be switched off unless
daylight is prevented from reaching the
module.
b) Development of extremely high
temperatures on their surfaces may
cause a fire
c) Toxic gases can be released from the
panels in case of high temperatures.
2. Which are the hazards that should be
assessed when preparing a risk
assessment and a method statement for
the installation of a PV system?
DC electricity is generated whenever PV
modules are exposed to daylight. Thus the
risk of shock from DC electricity should be
considered and mitigated.
Installing PV modules presents a
combination of hazards that includes risk
of electric shock (from DC electricity),
falling and manual handling difficulty.
3. Why is it not possible to use fuses to
protect PV module wiring?
a) PV modules are a current limiting
device, which means that fuse
protection is unlikely to be effective
under short circuit conditions and an
alternative approach to fault
protection is required.
b) PV modules are a current limiting
device, which means that fuse
protection is unlikely to be effective
under open circuit conditions and an
alternative approach to fault
protection is required.
c) Fuses can explode if exposed to low
current running through wire
connecting the components of the
system.
4. The behavior of DC electricity is different
from that of AC electricity; describe the
hazards associated with each one.
Both AC and DC electricity are capable of
causing death or injury as well as damage
to property.
Unlike AC, DC electricity is capable of
sustaining an arc across a gap between
conductors. This causes significant heating
and can cause substantial damage and
start a fire.
The natural reaction when receiving an
electric shock from an AC conductor is to
withdraw rapidly from the source of the
shock. However, if a DC conductor is
touched this can cause a muscle
contraction which makes it extremely
difficult to let go of the conductor.
5. The safety plan will be carried out by:
a) The user of the installation
b) The designer of the project
c) The installer.
6. Personal Protective Equipment include
(choose 3 answers):
a) Eye and face protection
b) Risk assessment plan
c) Protection of extremities
d) Elevating Work Platforms
e) Hearing protection
f) Mobile towers
7. The project report:
a) Explains the purpose of the project
and describes the procedure to be
followed for completion.
PVTRIN Training course - Trainers Worksheet 19
Part I HANDBOOK EXERCISES
AND SOLUTIONS
b) Contains the obligations of the installer
when executing the project.
e) Explains the potential risks and
preventive measures to be taken.
8. A Feasibility Study has to: (choose 3
answers)
a) Evaluate the energy needs and
interests of the user
b) Determine the potential level of solar
power generation of the region
c) Include a careful examination of what
could cause harm to people, during the
installation process,
d) Formalize and make solar installation
proposals according to the energy
needs of the customer.
e) Evaluate the extent of potential risks
involved during maintenance, taking
into account existing precautions
9. The structures used in a photovoltaic
installation must be:
a) Customised for each individual
installation.
b) There are no regulations regarding
structures.
c) Made of rustproof material and should
be maintenance free.
10. The safeguards that should be used for a
grid-connected photovoltaic installation:
a) Are up to the criteria of the designer.
b) Should fulfil the pertinent legal
requirements.
c) There are no pertinent legal
regulations.
11. For installations connected to single-phase
or triphased grids of 230V/400V, the
connection to the stream will be
connected
a) Downstream of the electric metre.
b) Upstream of the electric metre.
c) Wherever the client desires.
12. It is not really important that all modules
possess the same voltage - current
characteristics in case of series connection
a) True
b) False
13. In a stand-alone installation, consumption
takes place:
a) Exclusively in DC
b) Exclusively in AC.
c) In AC, DC or both simultaneously.
14. To ensure that the DC conductor section is
not too large, we should:
a) Lower the strain-voltage.
b) Increase the strain-voltage.
c) Ensure that the distance between the
generator and the point of
consumption is as long as possible.
15. The amount of a drop in voltage
admissible in power lines:
a) Will be defined by the applicable
regulation.
b) Depends exclusively on the criteria set
by the designer.
c) Will be determined by mutual
agreement between customer and
designer.
16. Regulators are installed in a cabinet which
will be:
a) as far as possible from the batteries,
not to be affected by battery vapours.
b) as close as possible to the batteries, to
avoid sudden drops in the voltage
c) as close as possible to the batteries, to
avoid sudden drops in voltage, but in
such way that it is not affected by
battery vapors.
17. The installer must provide the user with
an operational manual for the installation.
a) True
b) False
PVTRIN Training course - Trainers Worksheet 20
18. Before handing over the provisional
ownership of the installation:
a) It is necessary to allow the installation
running for a minimum of 240 hours.
b) There is no need to test the installation
operation.
c) Final approval is given only by the
customer.
19. It is necessary to run periodic checks on
the operational parameters of the PV
installation.
a) True
b) False
20. Which of the following components are
required for a grid-connected PV
installation?
a) Photovoltaic panels
b) Current / Voltage Regulator
c) Batteries
d) Stand-alone inverter
e) Grid-connected inverter
f) Water Expansion Vessel
g) Electrical Power Metre
21. Number the following steps of a Grid-
Connected PV Installation according to the
proper order.
a) Installation of PV Power Station 2
b) Wiring of Components 5
c) Installation of Safety and Measurement
Control Panels 3
d) Framework Installation 1
e) Final Test Run 7
f) Grid Connection 6
d) Assembly of Electrical Power Metres 4
5. CASE STUDIES – BEST
PRACTICES
No exercises
PVTRIN Training course - Trainers Worksheet 21
Part I HANDBOOK EXERCISES
AND SOLUTIONS
6. EXAMPLE INSTALLATION OF
A SMALL SCALE PV ON A
BUILDING
1. What actions should be undertaken prior
to the site visit? (choose 3)
a) Initial estimation of the plant with
respect to the available roof area,
b) Collection of climate data,
c) Plan in details the wire runs
d) Draft estimation of the output
e) Plan the precise location of BoS
2. Use PVGIS
http://re.jrc.ec.europa.eu/pvgis/apps4/pv
est.php to estimate the expected PV
output in Istria (Croatia). (Poly-Si, module,
optimized slope)
a) Approximately 1,200 kWh/kWp
b) Approximately 1,600 kWh/kWp
c) Approximately 800 kWh/kWp
3. Check the feed-in tariff in your area for
different sizes of PV system (10 kW, 30
kW).
A: This question is related with the local
legislative framework. Installer shall check
with the appropriate legal documents
level of feed-in tariffs for two mentioned
systems. For example, feed-in tariffs for
2011 in Croatia are:
C10 kW = 3.84 HRK/kWh = 0.51 €/kWh
C30 kW = 3.33 HRK/kWh = 0.44 €/kWh
4. If the cost of a 10 kW PV system is
€33,000, estimate the payback period for
an area with an average annual
production is 1,220 kWh/kWp and the FIT
is of 0.51 €/kWh.
a) Approximately 9 years
b) Approximately 5 years
c) Approximately 2 years
5. Estimate PV annual production for the
system of question 2 facing southwest
with an inclination of 15°. What is the
difference regarding a system with
optimal tilt?
a) Almost 100 kWh/kWp reduction
b) Almost 100 kWh/kWp increase
c) There was no difference
6. What data should be collected on site?
(Choose 3)
a) roof orientation and inclination
b) equipment characteristics
c) location of shadings
d) climate data
e) possible locations for placing BoS
7. The building has a two-pitched roof. One
faces south-east, and another north-west.
The inclination of the roof is 15° and its
dimension is 10 x 5 [m x m]. Select one
module type of 200 W.
7i. Choose part of the roof on which to place
the PV module.
a) north-west
b) southeast slope
7ii. Estimate the possible power of PV plant in
case PV modules are placed in landscape
(module’s dimensions 1.58m x 0.808m, 200
W, and from each end of the roof, 0.5 m for
margin must be selected).
a) 4 kW (4x5x200 W)
b) 5,6 kW
c) 8 kW
7iii. Estimate the possible power of PV plant
in case PV modules are placed in portrait.
a) 4 kW
PVTRIN Training course - Trainers Worksheet 22
b) 4,4 kW (2x11x200W)
c) 8 kW
8. In case of a 4.4kW PV system with 22
modules in 2 series, select an inverter that
will match the output characteristics of PV
array. Present the configuration of the
array and the inverter/s. (note: multiple
inverters could be selected).
Output characteristics of the modules
shall meet input characteristic of the
inverter. First, inverters with power range
around 4.4 kW shall be selected, and than
PV array shall be configured to meet its
characteristics. In this case, output
characteristics (under STC of PV modules)
are (from PV module datasheet):
UOC = 45.6 V UMPP = 36.9 V
ISC = 5.80 A ISC = 5.42 A
There are 22 modules, and PV array can
be configured as two strings with 11
modules connected in series (11x2). In this
case, output characteristics of the array
will be:
UOCA = n*UOC = 11*45.6 V = 501.6 V
UMPP = n*UMPP = 11*36.9 V = 405.9 V
ISCA = m*ISC = 2*5.80 A = 11.6 A
IMPPA = m*IMPP = 2*5.42 A = 10.84 A
In the series of 4.4 kW inverter (or similar
power), inverter with the range of input
voltage at least up to 501.6 V shall be
selected. For example, inverter with
maximum DC power rating of 4.6 kW and
input voltage range 320 – 630 V can be
selected.
Note: It is possible, for example, to use
one inverter with two MPP trackers, and
connected to them configuration of two
arrays as 6x2 and 5x2, or remove one
module and get configuration of 7x3, if
needed.
9. Calculate the angle of shading from a pole
that is located 25 m to the east of the PV
array, at a height of 10 m above the
modules. Place it in a solar diagram. Does
it obstruct direct sunlight to the PV
system?
Parameters of the shading are:
Height of the obstacle hOBSTACLE = 10 m
Distance of the obstacle dOBSTACLE = 25 m
Angle (height) of shading is calculated:
δShade = arctan (hOBSTACLE/dOBSTACLE)=
=arctan(10/25) = arctan (0.4) = 21.8°
Pole can be placed in solar diagram of the
location.
This shading obstructs direct sunlight, in
period from equinox. Any shading placed
with height higher than Sun’s lowest position
at noon at winter solstice will obstruct direct
sunlight in some period
10. Calculate the angle of shading from a tree
situated 10 meters to the south at a
height of 5 meters above the modules.
a) 30o
b) 26.6°
c) 60o
11. For the PV system in the figure below
estimate distance d so that the second
row is not shaded.
PVTRIN Training course - Trainers Worksheet 23
Part I HANDBOOK EXERCISES
AND SOLUTIONS
a) 0.998m
b) 2.0 m
c) 2.7m
PVTRIN Training course - Trainers Worksheet 24
7. MAINTENANCE AND
TROUBLESHOOTING
7.1. Maintenance plan
1. The frequency of the inspection and
maintenance of a photovoltaic system
should be:
a) Every 3 years
b) At least once a year
c) Every 5 years
2. Most of the problems in a PV installation
usually occur during the:
a) First year of operation
b) Second year of operation
c) Third year of operation
d) Fourth and sixth year of operation
3. The suggested frequency of cleaning the
PV modules surface is:
a) Twice a year for all the systems
b) Once a month for every installation
c) Depends on each installation’s
conditions
4. While measuring the total irradiance of a
PV array, the pyranometer should:
a) Be placed in the same direction as the
array
b) Be placed in the opposite direction of
the array
c) always face the north
d) always face the south
5. In order to check the specific gravity of the
electrolyte in the battery cells the meter
usually used is the:
a) ammeter
b) voltage meter
c) hydrometer
d) ambient meter
e) thermometer
6. Regarding the protection of the inverters
against lightning:
a) No additional equipment is used
b) Surge arrestors are used
c) Equipment for shortcut protection is
used
7.2. Typical mistakes and failures
1. One of the common failures regarding the
installation of PV mounting systems is the
distortion of the PV modules when they
are installed on the roof.
a) True
b) False
2. The most frequently reported faults
according to a great number of studies are
_____ faults.
a) inverter
b) battery
c) panel
d) wiring
3. While installing and connecting PV
modules, the Impp of each module should
be taken into account.
a) True
b) False
4. For electrical power supplies, the physical
operating life of power cables is generally
specified as:
a) 25 years
b) 45 years
c) 15 years
d) 35 years
5. A reason for exceeding the inverter
voltage could be:
a) The unpredictable weather conditions
PVTRIN Training course - Trainers Worksheet 25
Part I HANDBOOK EXERCISES
AND SOLUTIONS
b) The improper PV array design
c) A shortcut in the PV system
6. If there isn’t any current coming from the
PV array, a possible reason is broken or
corroded wiring.
a) True
b) False
7.3. Diagnostic procedures
1. The main advantage of the computer
operating as a data acquisition system for
PV systems is:
a) Its simplicity and robust construction
b) It has always lower cost than a logger
c) It is faster than the logger
d) It has wider choice of operational
modes and custom settings
2. The system should be set up and
calibrated preferably in the laboratory
a) True
b) False
3. Keeping records of the bar graphs of the
daily and monthly energy output:
a) Is used only to compare the yearly
energy performance of the PV system
with the yearly energy performance of
the commissioning report
b) It is a simple method to ensure the PV
system’s performance and perceive a
possible failure on the system.
c) It is useless because the data is stored
on the inverters of the PV system.
4. The mechanical problems can generally be
identified with a visual check
a) True
b) False
5. Wiring faults can be detected by checking
the inverter.
a) True
b) False
7.4. Documentation to the
customer
1. After the installation is completed, the
installer should make a commitment for
the yearly energy production of the
system by giving a minimum kWh
produced per year.
a) True
b) False
7.5. Maintenance checklist
1. A maintenance checklist for the inverter
should include (Choose 3 answers) :
a) Noise levels
b) Terminals condition
c) Open circuit voltage (V)
d) Impp (A)
e) Flooded vented to outside f) Dirt accumulation
PVTRIN Training course - Trainers Worksheet 26
8. QUALITY MANAGEMENT
AND CUSTOMER CARE
To help develop an appropriate QMS to
monitor the business, read the text in this
chapter and use the guidance contained in it
to prepare the following:
• A ‘Customer Enquiry’ form
• A ‘Site survey’ or ‘Building Assessment’
form
• A quotation template
• A standard customer contract
• A standard sub-contractor contract
• A standard procedure for designing PV
systems
• A risk assessment form
• A generic method statement
• A goods-in inspection form
• A procedure for reviewing the
contents of your QMS
• A list of relevant national Technical
Regulations, Building Regulations and
industry guides
• A list of documents to keep in each
customer’s job file
• A List of documents to hand over to
each customer
PVTRIN Training course - Trainers Worksheet 27
FURTHER PRACTICE:
MORE EXERCISES AND ACTIVITIES Part II
PVTRIN Training course - Trainers Worksheet 28
Part II FURTHER PRACTICE:
MORE EXERCISES AND
ACTIVITIES
1. SOLAR BASICS
1.1. Solar Photovoltaic (PV) Energy
1. The sun is the most abundant source of
energy on earth.
a) True
b) False
2. Which of the following energy resources is
not an indirect form of solar energy?
a) Coil
b) Wind
c) Nuclear
d) Waves
3. Match the correct words missing from the
figure below in numbers 1-4.
‘Hole Flow’ 4.
N-type 2.
Electron flow 1.
P-type 3.
4. PV cells convert sunlight into :
a) Electritcity
b) Heat
c) Both
5. PV installations generate an indirect form
of solar energy?
a) True
b) False
6. The electrical power generated by a PV
cell is determined by the intensity of the
sunlight?
a) True
b) False
7. A PV system cannot produce electricity
during cloudy or rainy days:
a) True
b) False
8. Match the correct type of radiation
shown in the figure above
PVTRIN Training course - Trainers Worksheet 29
Part II FURTHER PRACTICE:
MORE EXERCISES AND
ACTIVITIES
1. Diffuse Irradiance (3)
2. Albedo Irradiance (1)
3. Direct Irradiance (2)
9. What is the general way to identify the
sun’s position using the solar azimuth:
a) South = 0°, East = -90°, West = 90°
b) South = 0°, East =90°, West = -90°
c) South = 180°, East = -90°, West = 90°
10. The solar elevation angle has a fixed
value all over the year:
a) True
b) False
11. Match the correct angles shown in the
figure below
φ Zenith
a Azimuth
ψ Altitude
12. The level of pollutants contained in the
atmosphere has an impact on the power
output of a given PV system:
a) True
b) False
13. The same PV system under the same
direct irradiation will have a better power
output if it is surrounded by :
a) Grass
b) Snow
c) Concrete
14. How solar irradiation can be measured?
Choose the correct methods and classify
the selected measurement tools by their
accuracy (most/less accurate,
direct/indirect):
a) By analysing satellite images (indirect)
b) By using a pyranometer (the most
accurate measurement tool)
c) By using a PV sensor (the less accurate
one)
d) By using a Wattmeter and temperature
sensors
15. The total solar energy that reaches the
earth’s surface could exceed the existing
global energy needs by:
a) 1,000 times
b) 10,000 times
c) 100,000 times
16. What is the average energy received per
m² :
a) In South Europe: 1500-2000 kWh/m²
PVTRIN Training course - Trainers Worksheet 30
b) In the middle east: 1800 - 2300
kWh/m²
c) In North Europe: 900 -1400 kWh/m²
17. Europe’s entire electricity consumption
could be met if just 0,34% of the European
land mass were covered with PV modules.
a) True
b) False
1.2. PV system
1. Match the correct component of the PV
module indicated in the figure below
1. Out Glass Cover (7)
2. Photovoltaic Cell (3)
3. Support Structure (1)
4. External Connection (4)
5. Seal (9)
6. Cell Connections (5)
7. Back cover (6)
8. Encapsulant (2)
9. Insulation (8)
2. Why PV modules are connected in series?
a) To increase the total system current
b) To increase the total system voltage
3. A PV module can operate for more than
30 years.
a) True
b) False
4. Fill the gaps
a) Solar systems generate Direct Current
while most household appliances
utilize Alternating Current.
b) An inverter is installed in the system to
convert Direct Current to Alternating
Current.
1.3. PV technologies
1. Why solar cells are classified in three
different generations?
a) Because second and third generation
solar cells have a better efficiency
b) Because solar cells from each
generation are produced in a totally
different way
c) Because second and third generation
solar cells are cheaper
2. What are the common characteristics of a
first generation solar cell?
a) 225 cm² and 4.5 Wp
b) 1.7 m² and 250 Wp
c) 20 m² and 3000 Wp
3. Fill the gaps with the correct answer. You
can choose between the following values:
7m2, 8m2, 10m2, 15m2.
− The area needed for a Polycrystalline
Silicone panel is approximately
__8__m2
− The area needed for a Thin Film a-Si
panel is approximately __15__m2
− The area needed for a
Monocrystalline Silicone panel is
approximately __7__m2
4. Thin-film technologies are not using silicon
as the active material
a) True
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b) False
5. Which technology has achieved the
highest efficiency in laboratory among the
thin-film technologies?
a) a-Si
b) a-Si/µc-Si
c) CIGS
d) CdTe
6. Efficiencies above 40% have been
achieved in laboratories with CPV
modules.
a) True
b) False
7. Due to their high efficiency, CPV modules
are the best solution for any area in the
world.
a) True
b) False
8. Classify all the solar cells technologies by
their efficiency :
a) CdTe 5
b) CPV 1
c) a-Si/µc-Si 6
d) Multi-cristalline silicon 3
e) OPV 8
f) Mono crystalline silicon 2
g) CIGS 4
h) a-Si 7
1.4. Type of PV systems and
application
1. The objective of a grid-connected
photovoltaic installation is:
a) Self-sufficiency.
b) Inject the energy generated into the
grid for free.
c) Inject the energy generated into the
grid for sale.
2. Match the correct component of the off
grid PV system indicated in the figure
below
1. Batteries (5)
2. Electrical Appliance (2,6)
3. Inverter (4)
4. Photovoltaic Module (1)
5. Charge Controller (3)
3. Indicate the type of the following panel
1.
2.
3.
1. Poly-Si
2. Mono-Si
3. a-Si Thin Film
PVTRIN Training course - Trainers Worksheet 32
4. Off-grid PV systems are always small
home systems.
a) True
b) False
1.5. Benefits of PV technology
1. The energy payback time of a PV system is
negative. It will not produce the energy
necessary to its fabrication over its
lifetime.
a) True
b) False
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2. DESIGN PRINCIPLES
2.1. Site Survey
1. Modules shading, in case of a group of
trees, depends on:
a) the height of the tree
b) the distance from the array
c) the direction of the tree with respect
to the array.
d) all the other answers
2. Temporary shading may lead to losses up
to:
a) 1%
b) 12%
c) 8%
d) 5%
3. A _____ tilt allows the solar panel to self-
clean
a) 5o
b) 10o
c) 15o
d) None of the other answers
4. Three areas of the building where PV
modules can easily be integrated are:
a) the roof
b) the façade
c) the sun screening components
d) all the other answers
5. A minimum of six hours of un-shaded
operation is important for best system
performance.
a) True
b) False
6. Temporary shading can be considered the
fallen leaves, snow, air pollution and
neighbouring buildings.
a) True
b) False
7. In the southern hemisphere, the sun rises
to its greatest height at noon on the
Summer Solstice and sinks to its lowest
angle at noon on the Winter Solstice.
a) True
b) False
8. Match the correct steps to be followed
during the process of estimating whether
a site is appropriate for PV installation
Step 1. Use the compass to locate the East
(Step 2)
Step 2. Note the height of each obstacle
on the solar map (Step 4)
Step 3. Stand in the middle of the
proposed field (Step 1)
Step 4. Use the sextant measure the
height of each obstacle (Step 3)
Step 5. Connect spots on the solar map
and determine the area shaded
(Step 6)
Step 6. Rotate 15o degrees, with back to
the north, and repeat previous
steps until face the west (Step 5)
2.2. System Sizing and Design
1. Put in the correct order the 6 main steps
which a technician should follow to design
a grid connected system.
a) Array configuration (5)
b) Check inverter’s compatibility (6)
PVTRIN Training course - Trainers Worksheet 34
c) Estimate roof size needed for the
selected (1)
d) Check the module voltage (3)
e) Module configuration (4)
f) Check if the module fit the roof (2)
2. A tilt angle of _____ is usually selected,
at Central European latitudes, to
maximize PV panels efficiency throughout
the year
a) 15o
b) 30o
c) 60o
d) None of the other answers
3. For the following situations, which one
could result in the most cost-effective use
of a two-axis tracking mount?
a. Latitude 30°, and moderate daytime
summer cloud cover
b. Latitude 35°, and minimal daytime
summer cloud cover
c. Latitude 28°, and moderate year-around
cloud cover
d. Latitude 32°, and minimal year-around
cloud cover
4. For off-grid system, designed to perform
best in winter, the array should be tilted at
an angle of latitude :
a) (φ) + 15o
b) (φ) - 15o
c) (φ)
d) (φ) + 30o
5. Match the optimum tilt (left column) for a
PV panel installed in the Northern
Hemisphere
β = φ In areas with limited sunshine
in order to exploit diffuse
radiation (β = 0⁰)
β = φ + 15⁰ In humid climate areas
(β = φ - 15⁰)
β = φ - 15⁰ In areas with a latitude of less
than 20o around the equator
(β = 5 - 10⁰)
β = φ - 15⁰ Throughout the year
(β = φ)
β = 5 - 10⁰ Performs best in summer
(β = φ - 15⁰)
β = 0⁰ Performs best in Winter
(β = φ + 15⁰)
6. If the PV modules, on the roof of the
building of the following figure, are
installed in the optimum way which is the
correct orientation? (The building is sited
in the Northern Hemisphere).
a) 1.
b) 2.
c) 3.
d) 4.
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7. The loss in the output of a panel, even half
of a cell is shaded, is the same as if half of
a row is shaded.
a) True
b) False
8. Roof mounted systems should have an
available space of at least ____ beneath
them
a) 50mm
b) 80 mm
c) 15 mm
d) None of the other answers
9. For the panels in the next figure choose
the minimum distance A to avoid shading.
a) ̴ 4.0m
b) ̴ 3.0m
c) ̴ 4.5m
d) ̴ 2.0m
10. Autonomous systems can only be sized
effectively:
a) for predictable loads
b) for random load estimations
c) either a or b
d) None of the other answers
11. Typical Performance Ratio are:
a) 60-75%
b) 60-75%, but even higher can be
achieved
c) 40-50%
d) <40%
12. The I-V characteristic curve is valid under:
a) 1,000W/m2, 25°C
b) 1,000W/m2, 20°C
c) 1,024W/m2, 25°C
d) 1,000W/m2, 18°C
13. For a PV module, IV curves for different
percentages of shading are presented in
the graph below. Match the numbered
curves with the corresponding percentage
of shading.
1. 1 cell 75% shaded 3.
2. Unshaded module 1.
3.. 1 cell 25% shaded 2.
4. 1 cell 100% shaded 4.
14. For a PV module, IV curves for different
temperatures are presented in the graph
below. Match the numbered curves with
the following values of temperatures.
PVTRIN Training course - Trainers Worksheet 36
1. 40oC 3.
2. 0 oC 1.
3. 20oC 2.
4. 60oC 4.
15. For the figure below match letters A to C
with the correct value of irradiance
A.
600 W/m2 C.
B. 1000 W/m2 A.
C. 800 W/m2 B.
16. Estimate the correct fill factor for the
following module’s characteristics : VMMP
=16V, IMPP = 0.6A, Isc =0.62A, VOC=21V
a) ̴ 73%
b) ̴ 78%
c) ̴ 1.4%
17. The operating temperature of PV cells is
determined by:
a) the ambient air temperature
b) the characteristics of the
encapsulation,
c) the intensity of sunlight falling on the
module,
d) all the other answers
18. For the following simplified PV system
estimate the total Volts and total Amps of
the 4 PV modules and the battery storage
a) PV array : 12VDC,14A, Battery
Storage: 12VDC, 700AH
b) PV array : 12VDC, 7A, Battery
Storage: 12VDC, 350Ah
c) PV array : 12VDC,14A, Battery
Storage: 12VDC, 350Ah
d) PV array : 12VDC, 7A, Battery
Storage: 12VDC, 700Ah
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19. For the following simplified PV system
estimate the total Volts and total Amps of
the 4 PV modules and the battery storage
a) PV array : 12VDC,14A, Battery
Storage: 12VDC, 700AH
b) PV array : 24VDC, 14A, Battery
Storage: 24VDC, 700AH
c) PV array : 12VDC, 14A, Battery
Storage: 24VDC, 350AH
d) PV array : 24VDC, 7A, Battery
Storage: 24VDC, 350AH
20. If 24 PV cells (0.5V & 1.25A) are connected
in series and parallel (6 cells and 4 rows).
The total voltage across the load is:
a) 2.0 V
b) 2.4 V
c) 12.0 V
d) 3.0 V
21. If 24 PV cells (0.5V & 1.25A) are connected
in series and parallel (6 cells and 4 rows).
The total current through the load is:
a) 2.0 A
b) 6.0 A
c) 1,8 A
d) 0.5 A
22. If 24 PV cells (0.5V & 1.25A) are connected
in series and parallel (6 cells and 4 rows).
The total power across the load is:
a) 18.0 W
b) 3,0 W
c) 12.0 W
d) 1.0 W
23. For the circuit below match the numbers
shown with the correct meter.
a) Ammeter (2)
b) Voltmeter (1)
24. A technician should never connect
modules, utilising different
technologies, in series as:
a) The system array would not operate
b) Interconnecting cells with different
capacities will result in the phase
current being determined by the
weakest cells
c) This would probably lead to cell
deterioration
d) The statement is wrong this connection
would not cause any problems
25. An energy consuming device of 200 W
with 12V rated voltage is used in a house,
10 m away from a PV system. The drop of
voltage is 10% and κCu = 56m/mm2Ω. The
appropriate cross-section of the cable is:
a) 2.5 mm2
PVTRIN Training course - Trainers Worksheet 38
b) 4.0 mm2
c) 6.0 mm2
d) 1.5 mm2
26. Estimate the total efficiency of an
autonomous system if nPV =0.8, nPV-BAT
=0.97, nCC =0.98, nBATT =0.9, nDIST =0.97, nINV
=0.9
a) 0.6
b) 1.0
c) 0.5
d) None of the other answers
27. The power range of the inverter can be
specified for the sizing range:
a) 0,8x PPV < DC power rating of the
inverter < 1,2x PPV
b) 1,1x PPV < DC power rating of the
inverter < 1,2x PPV
c) 0,5x PPV < DC power rating of the
inverter < 1,5x PPV
d) 0,4x PPV < DC power rating of the
inverter < 0,8x PPV
28. Match the correct type of inverter output
waveform with the graphs below
1. Sine Wave 3.
2. Square wave 1.
3. Modified Sine Wave 2.
29. In order to avoid damages the highest
voltage must be______ than the
maximum DC input voltage at the inverter
a) lower
b) higher
c) equal
d) None of the other answers
30. A string concept with 8 inverters is
planned for the PV system with 12 kWp.
What the DC output that each inverter
should have? Between…
a) 1,35 and 1,5 kW
b) 0,67 and 1,42 kW
c) 1,35 and 1,42 kW
d) None of the other answers
31. In the low voltage concept shading has
less effect compared to longer strings.
a) True
b) False
32. String fuses can be used to protect cables
from overloading and are usually used for
systems with more than four strings.
a) True
b) False
33. The DC main cable is in general sized to
____ times the PV array short-circuit
current at STC
a) 1,0
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b) 3,0
c) 1,25
d) 2,75
34. A safety distance, between the PV plant
and all parts of the lightning protection
system, of more than ______ has to be
kept.
a) 0,5m
b) 0,1m
c) 0,3m
d) 0,2m
35. An equipment-grounding conductor is a
conductor that normally carries current
and is connected to earth.
a) True
b) False
36. In case that the PV system is located inside
the existing protection zone of a building a
protection device is needed to protect it
against lightning strikes.
a) True
b) False
37. If a proposed PV installation site has a
south-facing roof area of 100 m2, and if PV
modules with 0.0065 W/cm2 output at STC
are to be installed on 50%, 30% and 40 %
of the roof, then the maximum available
PV array output power (based on the sum
of module ratings) at STC will be
approximately. (fill the gaps)
a. 50% __3,250__W
b. 30% __1,950__ W
c. 40% __2,600__ W
38. Lead-acid batteries, are:
a) cheap
b) reliable
c) have relatively good energy storage
density
d) all the other answers
39. A household of 3 people requires around
3,500 kWh of electrical energy annually.
Which is the polycrystalline PV module
surface area in order this energy to be
delivered annually, if the irradiation
strength in a year is 1,350 kWh/m²?
a) 10.4 m2
b) 18.5 m2
c) 7,4 m2
d) 37.2 m2
40. Calculate the additional energy that is
required to run the following devices in
standby mode for a year:
- Telephone (12 W)
- Audio system (20 W)
- Fax machine (8 W)
a) 40 W
b) 350 kWh
c) 146 kWh
d) 9,600 W
41. Fill the gaps. In a holiday cottage the
owner needs to provide power for lights
(100W), a TV (60W) and a low energy AC
refrigerator (80W). The daily hourly use of
lights and TV is approximately 3 hrs. So if
the daily energy requirement for the
refrigerator is 400Wh. The total energy
PVTRIN Training course - Trainers Worksheet 40
needs for the appliance is__880Wh_. If
PSH=4.5 and the performance of the
system 61.1%. The peak Wattage of the
array required is __320W__.
42. Batteries in a PV system are not
influenced by temperature variations.
a) True
b) False
43. When the electrolyte of a battery freezes
the technician should
a) Replace the battery with new one
b) Not charge the battery
c) Try to slowly discharge the battery
d) Heat the battery in order to restore it
44. Which of the following characteristics are
required for a stand- alone inverter :
a) very good conversion efficiency, even
in partial load range
b) tolerance against battery voltage
fluctuations
c) economical standby state with
automatic load detection
d) all the other answers
45. The followings should be taken into
consideration during the selection of an
inverter:
a) system voltage
b) PV array and load currents
c) battery type and size
d) all the other answers
46. In several cases PV tiles may not be as
efficiently as expected.
a) True
b) False
47. Match the following words to the
graphical symbols
1. Direct Current 5.
2. Alternating Current
1.
3. Voltmeter 4.
4. Semiconductor
diode 2.
5. Battery of
accumulators 3.
6. Photovoltaic cell
7.
7. Earth
6.
48. Match each one of the following device to
the correct definition.
1. MPP
regulator:
device connected in parallel
to a PV module to provide an
alternate current path in case
of module shading or failure
(5.)
2. Inclino
meter:
device that can measure
voltage, current and
resistance (7.)
3.Grounding
conductor
device that searches for the
best operating point of a
module and ensures that the
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module delivers the
maximum possible power
under all conditions (1.)
4. Diode: device used to connect the
frame of an electrical device
to the ground.
(3.)
5.Bypass
Diode:
device that breaks the
electrical circuit if too much
current is present (6.)
6.Fuse: device that allows current to
flow in one direction only (4.)
7.
Multimeter
device for measuring angles
of slope and inclination of an
object with respect to its
gravity by creating an
artificial horizon (2.)
49. For the layout of the stand-alone PV
system match the numbers in the figure
below with the correct component.
1. Inverter (4)
2. Accumulator (3)
3. Solar Generator (1)
4. Charging Regulator (2)
5. Auxiliary assembly unit (6)
6. Consumer (5)
2.3. Economics and Environmental
Issues
1. PV modules price is reduced by almost
_____, each time that the cumulative
installed capacity (in MW) is doubled.
a) 20%
b) 2%
c) 6%
d) 40%
2. Fill the gaps. A home owner will invest
maximum of €25,000 in a PV system. The
estimated cost of the system is €2,000
/kW. The initial estimation for the
required system is 12.5 kW. The owner
wants the highest possible output from
the array so (choose one: mono-Si, poly-
Si, a-Si) mono-Si modules were
selected.These panels require (choose
between : 3m2, 6m2, 8m2) 9m2/kW. The
available surface area dimensions are L =
9m and D =10m. So the largest array he
can get is 10 kW and the cost of the
system will approximately be: € 25,000.
3. When investing in a PV system, one may
estimate expected cash flows over the
lifetime of the system for
a) 20-25 years
b) 30-35 years
c) 10-15 years
d) 5-10 years
4. Emissions of greenhouse gases are
expressed in:
a) CO2
b) CO2-equiv
c) CO2- CO
PVTRIN Training course - Trainers Worksheet 42
d) None of the other answers
5. PV plants in fields cover an average of:
a) 25 km2/GWp
b) 20 km2/GWp
c) 12 km2/GWp
d) 10 km2/GWp
6. The basic environmental and health issues
coming from manufacturing PVs? are:
a) the dispersion of kerf dust, coming
from the sawing of silicon ingots into
wafers
b) the exposure to solvents used in wafer
etching and cleaning
c) None of the other answers
d) both a and b
7. Materials used to produce PV
modules are
a) harmless
b) dangerous and toxic
c) can be dangerous under certain
circumstances
d) None of the other answers
8. According to the European Photovoltaic
Industry Association, in 2011, photovoltaic
installations grew 11 GW over 2010. How
many tonnes of CO2 emission were
avoided by installing this PV capacity, if a
coal-fired power station pollutes the
atmosphere with 0,989 kg CO2 for every 1
kWh of energy delivered. In order to
calculate this for one year, assume 1,200
hours of sunlight.
a) 13 million tonnes
b) 13 million kilograms
c) 20 million tonnes
d) 20 million kilograms
9. Match each one of the following
terms to the correct definition.
1.Learning
curve
the time in which the energy
input during the PV system
life-cycle is compensated by
electricity generated by the
PV system (3)
2. IRR a graph presenting the rate of
learning. In PVs this is often
related to the world PV
production price (1)
3. EPBT the actual annual profit rate
of an investment. It equates
the value of cash returns with
cash invested (2)
4. LCA assessment to quantify and
evaluate the environmental
burdens over the life cycle of
a product, process, or activity
(4)
2.4. Standards and regulations
1. Administrative permitting procedures may
involve:
a) obtaining building permits
b) environmental impact assessments
c) grid connection licenses
d) all the other answers
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2.5. Open questions
1. Name three categories of shading that can
lead to decrease of the PV system
efficiency.
temporary, resulting from the location, self-
shading, resulting from buildings
2. Name two types of tracking systems. What
is the main advantage and main
disadvantage of these systems
- One axis tracking. Advantage: Output can
be increased, approximately at 20%,
compared to a fixed array.
- Two axis tracking: Advantage: Power
output, is approximately 40% increased
compared to fixed array.
Disadvantage: tracker’s moving parts require
maintenance; potential failures, may
decrease reliability and increase maintenance
costs.
3. Describe some measures for protection
against lightning.
Use of a single ground electrode, connect all
the metallic parts of the electric equipment
ground, arrange of the cables to avoid loops
that can produce over-voltage generation,
install of lightning protectors connected to
the protected equipment ground
4. Describe the ideal charging cycle of a
battery.
i. the battery is charged at constant current
until the voltage reaches a predefined value,
ii.the voltage is held constant while the
charging current decays, iii. after suitable
time the charging voltage is reduced to avoid
excessive gassing and loss of electrolyte.
5. Name at least three simulation models
that can be used in PV system design.
PV*SOL, PV F-CHART, RETScreen, PVSYST, PV-
DesignPro etc
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3. BAPV and BIPV
3.1. Mounting and building
integration options
1. Name 4 of the main criteria to be taken
into account for reliable integration of PV
modules in buildings:
a) Natural integration
b) Different materials
c) Architectural solutions
d) Pleasant composition of materials and
colours
e) Available connection to the grid
f) In line with the context of the building,
g) Limited to the roof of the building
h) In line with the more recent fashion
trends
2. Which 2 types of the following structures
can be used for fixing PV modules on flat
roofs?
a) Wooden structures
b) Metal structures
c) Reinforced concrete structures
d) Plastic structures
3.2. BIPV and BAPV on roofs
1. i. Which type of PV modules are easier to
install on pitched roofs?
a) BAPV
b) BIPV
1.ii Why is that?
a) The modules are smaller
b) The cabling is easier
c) They have an independent support
structure
2. Can we install PV modules on roofs close
to chimneys, exits and paths?
a) Yes
b) No
3. Which is the best orientation of the street
when installing PV modules on sloped
roofs?
a) South-north
b) East-west.
4. The efficiency of the PV modules on
facades compared to PV modules on roofs
in the same building
a) is higher
b) is at least 30% lower
c) there is no difference.
5. The operating temperature which could
be reached at a roof integrated PV system
without ventilation is?
a) 40°C
b) 20°C
c) >50°C
6. Match the following figures to the correct
legend
1
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2
a) BIPV (2)
b) BAPV(1)
3.3. BIPV and BAPV on façades
1. What is the difference between ventilated
facade and curtain wall facade?
a) Ventilated facades have additional
mechanical ventilation
b) Curtain wall facades are completely
separate from the building
c) Curtain wall facades need additional
cladding or other finishing
d) The space between the wall and the
module is up to 10 cm for ventilated
facades and more than 20cm for
curtain wall facades.
2. Match the figures below to the correct
legend
1 2
a) BIPV in cold façade (2)
b) BIPV in warm façade (1)
3.4. Glass roofs, shading systems
and other applications
1. Match the figures below to the
correct legend.
1. 2. 3.
a) Opaque Panels (2)
b) Transparent Panels (1)
PVTRIN Training course - Trainers Worksheet 46
c) Transparent Thin Panels (3)
2. The following figures illustrate examples
of PV parasols with and without a water-
retaining function. Which figure illustrates
PV parasol with water-retaining function?
a)
b)
a) Figure a
b) Figure b
3.5. Design Parameters and
Performance Factors
1. Name three advantages when shading
devices are composed of PV modules
a) They are cheaper than traditional
shading devices
b) They ensure passive cooling
c) There is no need of cladding on the
facade
d) They ensure good daylight control
e) They produce electricity
f) They are easier for maintenance than
traditional shading devices.
2. The following figures show different
solutions for urban planning. Which is the
best from point of view of PV
installations? (rate the best with 1 and the
worst with 4)
Figure a
Figure b
PVTRIN Training course - Trainers Worksheet 47
Part II FURTHER PRACTICE:
MORE EXERCISES AND
ACTIVITIES
Figure c
Figure d
a) Figure a: – 2
b) Figure b: – 1
c) Figure c: – 3
d) Figure d: – 4
3. Does the temperature dependence of the
voltage affect the PV module power
output?
a) Yes
b) No
4. Which are the risks for a PV system if the
operating temperature is not taken into
account?
a) Risk of failure
b) Risk of fire
c) Risk of failure and risk of fire.
PVTRIN Training course - Trainers Worksheet 48
4. INSTALLATION – SITEWORK
4.1. Working safely with PV
1. Which actions are required before start
working with solar electric system?
a) De-energize all circuits.
b) Clean our hands
c) Wear comfortable clothes
d) Use a meter or circuit test device
e) It´s imperative to use protective
gloves
2. Which of the following statements are
true about batteries? (choose 4)
a) Dead batteries are out of danger for
any person operating them.
b) There is no problem working with
batteries if they´re disconnected
c) Lead Acid can be harmful
d) When working on batteries eye
protection measures are highly
recommended
e) We should always open the Main DC
disconnect switch between the
batteries and the inverter before
working on battery banks
f) Battery bank contains electric danger.
g) Metal tools and personal jewelry can
create arcing on batteries
3. When preparing method statements and
risk assessments, considerations should
be given to (Choose 2 answers):
a) The payback time of the project
b) The equipment required to ensure the
safety of the installer
c) The current trends in the sector
d) The safe operation of the installed
system
e) The estimated budget of the project
4. A risk assessment should always be
carried out before practice in the
workplace.
a) True
b) False
5. A developed risk assessment:
a) can be used for different projects
b) can be used for projects with similar
characteristics
c) has to be adapted to individual
circumstances and needs
6. Small amounts of sunlight on PV panels
can produce a voltage potential and shock
or arc-flash hazard
a) True
b) False
7. An electric arc-flash hazard is unlikely to
appear while adding or removing a series
of solar PV panels
a) True
b) False
8. Choose the correct word (Always/ Never)
in the gaps below.
- Never disconnect PV module connectors or
other associated PV wiring under load
- Always open the DC Disconnect Switch prior
to working on a solar PV system.
- Care should always be taken to prevent
arcing at or near battery terminals.
- Always open the Main DC disconnect switch
between the batteries and the inverter
prior to servicing or working on the battery
bank.
PVTRIN Training course - Trainers Worksheet 49
Part II FURTHER PRACTICE:
MORE EXERCISES AND
ACTIVITIES
9. It is preferable to use leaning ladders
rather than mobile elevating work
platforms when working on heights
a) True
b) False
10. Personal protective equipment is a
substitute for good engineering or
administrative controls or good work
practices.
a) True
b) False
11. There is no problem when locating PV
modules near sites with flammable gases.
a) True
b) False
12. A PV installation can develop lethal DC
voltages if inadequately earthed.
a) True
b) False
13. The risk of shock is seriously increased if a
PV module is damaged.
a) True
b) False
4.2. Installation plan
1. The on-site mounting process consists of
the following steps. Number them
according to the correct order.
a) Operating and testing the system 7
b) Connecting the PV modules. 3
c) Mounting structures 1
d) Connecting components 6
e) Mounting the photovoltaic field 2
f) Layout of tubes and conduit 5
g) Mounting the corresponding
distribution board 4
2. The safety plan may be more or less
extensive, but it should at least include
(Choose 4 answers) :
a) Tools that are allowed to use
b) List and description of the works to be
performed
c) list of any safety measures to be taken
d) International Regulation
e) Description of safety rules to follow
f) Protective equipment that are allowed
g) List of existing risks and detailed
precautions to be taken
h) health status of each person
3. The quality of the system installation has a
strong influence on the ongoing
performance of the system.
a) True
b) False
4.3. Electrical components
installation
1. Connection of parts of a PV system to
earth protects (3 correct answers) :
a) against electric shock to people in the
installation neighbourhood
b) against fire under fault conditions
c) The panels from generating
electromotive force
d) against lightning induced surges
e) against arcing when disconnecting the
modules
2. In general, the different types of
protection to be considered (Choose 3
answers):
a) Protection against indirect contact
b) Protection against direct contact
c) Protection in AC portion
d) Protection against overcurrent
e) Protection in DC portion
PVTRIN Training course - Trainers Worksheet 50
3. If the maximum system voltage of a PV
system is greater than______, then, as a
rule, one conductor should be grounded.
a) 5V
b) 50V
c) 120V
d) 240V
4. Match the correct term to each one of
following definitions. a) Isolating
transformer
Earthing arrangement whereby
the supply neutral and earth are
combined into a single conductor
(c)
b)
Equipotential
Zone
Device which the input and
output windings are electrically
separated by double or
reinforced insulation (a)
c) Protective
Multiple
Earthing
Area in which exposed- and
extraneous-conductive parts are
maintained at substantially the
same potential by bonding (b)
5. Bonding of any of the current carrying DC
conductors to earth is recommended.
a) True
b) False
4.4. Equipment Installation
1. Why is important to insulate two different
metals before contact?
a) to prevent a real risk of electric shock
b) to increase the efficiency of the
module
c) to keep the temperature of the wiring
low
2. To prevent potential mistakes in joining
panels, the use of technical drawings,
taking into account the position and
wiring of modules, are highly
recommended.
a) True
b) False
3. The form of output wave of a stand-alone
inverter it´s highly recommended to be:
a) squared
b) modified sine
c) pure sine
4. The inverter should be positioned in an
enclosed space, sheltered from the
outside weather.
a) True
b) False
5. In order to avoid losing voltage a stand-
alone inverter, should be installed:
a) placed inside a watertight box
b) as close as possible to the storage
batteries
c) as close as possible to the regulator
d) as close as possible to the PV Modules
6. The batteries should always be located
a) in open spaces where there is
adequate ventilation
b) in an open location, avoiding shade
c) in an enclosed ventilated area.
7. The most important features when
selecting a battery are: (Choose 3
answers)
a) Capacity
b) Currents trends
c) Physical characteristics
d) Applied technology
e) Type of terminals
8. The main disadvantage of Ni-Ca batteries
is that they are much more expensive than
gel batteries.
a) True
b) False
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Part II FURTHER PRACTICE:
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9. When filling batteries with electrolytes
there is no need for any safety measure.
a) True
b) False
10. Select the option that explains the
following image:
a) 12V. 200 Ah Series Connection
b) 12V. 100 Ah Parallel Connection
c) 24V. 100 Ah Series Connection
d) 24V. 100 Ah Parallel Connection
e) 24V. 200 Ah Series Connection
f) 12V. 200 Ah Series Connection
11. Select the option that explains the
following image:
a) 12 V. 200 AH. Parallel Connection
b) 48 V. 100 Ah. Series Connection
c) 24 V. 100 Ah. Parallel Connection
d) 48V. 100Ah. Series Connection
e) 48V. 400 Ah Parallel Connection
f) 24V. 100 Ah. Series Connection
12. Select the option that explains the
following image:
a) 48V. 400Ah Mixed Connection
b) 24V 200Ah Parallel Connection
c) 48 V 200 Ah Series Connection
d) 12V 400 AH Mixed Connection
e) 24V 200 Ah Mixed Connection
13. Fill the gap: Regulators in parallel may be
used in________ consumption
installations due to the type of regulation
employed.
a) low or high
b) low
c) high
PVTRIN Training course - Trainers Worksheet 52
14. Which is the sequence of actions which
must be strictly followed when connecting
the regulator? Number the following steps
:
a) Connect the load to the regulator
terminals as indicated, respecting the
polarity. (3)
b) Connect the storage battery to the
regulator terminals, designated with
the battery symbol. This way, the
regulator receives the preferred
voltage to feed into its circuit. (1)
c) Connect the PV generator field to the
regulator terminals labeled for the
module. (2)
4.5. Mechanical Components
Installation
1. The materials employed in the structures
construction may vary as a function of the
type, the environment, resistance, etc. But
the main materials in use are: (Choose 4
answers)
a) Aluminum
b) Bronze
c) Steel
d) Copper
e) Iron
f) Titanium
g) Wood
h) stainless steel
i) fibreglass
j) polybutylene
2. The structure of PV module should be
placed….. Choose the correct answer
a) in an open location, free of shade
b) in places where it is very hot
c) In such a way so that the PV panels will
be inclined at 25 °
d) In an optimal orientation and tilt
3. What is the purpose of mounting mobile
structures?
a) To have the PV modules correctly
oriented toward the sun at all times
b) To avoid overheating the module
c) To collect maximum diffuse irradiation
4. Solar Tracking. Choose the correct title on
each picture. (FLASH CARDs)
a) Tracking North to south
b) Tracking the altitude of the sun
c) Left and right Tracking
d) Tracking the solar Azimuth
e) Up- Down Axis
f) Dual tracking Axis
d) Tracking the solar Azimuth
b)Tracking the altitude of the sun
f) Dual tracking Axis
PVTRIN Training course - Trainers Worksheet 53
Part II FURTHER PRACTICE:
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ACTIVITIES
4.6. Grid-connected PV Systems
1. Select the correct name of each of the
parts of a Grid-connected PV System:
[MULTIPLE CHOICE + IMAGE]
Direct Current Line, AC Protections,
Accountants consumption supply, PV
Generator, Direct Current Protection,
Alternating current line, Alternating
current and Direct current converter.
Corrrect Figure
4.7. Stand-alone PV System
1. Select the correct name of each of the
parts of a stand alone PV System. Some of
the following parts may be repeated and
some others should be ignored
[MULTIPLE CHOICE + IMAGE]
• Regulator
• AC Consuption
• DC Grid connected installation
• AC Grid Connected installation
• Stand Alone Converter
• Batteries
• DC Consumption
• DC Stand Alone installation
• AC Stand Alone Installation
• Inverter
• Grid conected converter.
Corrrect Figure
PVTRIN Training course - Trainers Worksheet 54
4.8. Mounting system and building
installation.
1. The glass-glass modules for façades and
skylights, in most cases, have an easy-to-
handle electricity connecting system.
a) True
b) False
4.9. Completing the PV installation
1. Simultaneous monitoring of solar
radiation can present practical difficulties
unless the system has a radiation sensor
installed and its cable is accessible at the
place where testing is carried out.
a) True
b) False
2. The installer has to provide a copy of the
project report which may include the
followings. Choose 5 answers.
a) Sizing Study
b) Feasability study
c) Shadow study
d) Τechnical specifications
e) Technical Drawings
f) List of Conditions
g) Building permission
h) Budget
i) Safety Plan
PVTRIN Training course - Trainers Worksheet 55
Part II FURTHER PRACTICE:
MORE EXERCISES AND
ACTIVITIES
5. CASE STUDIES – BEST
PRACTICES
1. Visit the following website
http://www.bipv.ch/index.php?option=com_
content&view=article&id=256&Itemid=229&l
ang=en
As regards the BIPV installation in the
house, in the photo, it is sited in the optimum
way so that the panels will produce the
maximum energy.
1i. The tree in the photo is located on the
a) North
b) South
c) West
d) East
1ii. The roof covered by the mono-Si PVs is
approximately
a) 100m2
b) 200m2
c) 300m2
d) 50m2
2. The way that PVs are installed in the
following case study
http://www.bipv.ch/index.php?option=com_
content&view=article&id=271&Itemid=230&l
ang=en
is not recommended, in general, as the
panels are not inclined and the efficiency is
very low.
a) True
b) False
3. The main advantage of the system
presented in the following case study
http://www.bipv.ch/index.php?option=c
om_content&view=article&id=295&Itemi
d=218&lang=en,
is :
a) the high-quality natural light which is
provided inside the building
b) the aesthetic result is rather high
c) the energy produced compared to
opaque PVs is higher
4. The maximum transparency which PV
modules achieve in general, is reached in
the following application
http://www.bipv.ch/index.php?option=c
om_content&view=article&id=266&Itemi
d=215&lang=en
a)True
b) False
5. The PV systems in the building presented
in the link below
http://www.pvdatabase.org/projects_vie
w_detailsmore.php?ID=208
a) are BIPV
b) are BAPV
c) are BIPV and roof mounted
d) None of the other answers
6. The PV installation in the following link,
faces North,
http://www.pvdatabase.org/projects_view_d
etailsmore.php?ID=205 which means reduced
efficiency compared to a system facing the
South.
a)True
b) False
7. The coloured solar cells of the case study
presented in the following link
http://www.pvdatabase.org/projects_vie
w_detailsmore.php?ID=209
a) produce more energy than the
common dark color cells
b) give a unique look to the solar
installation
c) usually produce the same amount of
energy as the dark blue cells
PVTRIN Training course - Trainers Worksheet 56
8. Make a draft estimation of the payback
period of the following PV system
http://www.pvdatabase.org/projects_view_d
etailsmore.php?ID=383 , assuming that the
investment cost was 3,250€/kW.
a) 2 years
b) 13 years
c) 9 years
6. EXAMPLE INSTALLATION OF
A SMALL SCALE PV ON A
BUILDING
No exercises
PVTRIN Training course - Trainers Worksheet 57
Part II FURTHER PRACTICE:
MORE EXERCISES AND
ACTIVITIES
7. MAINTENANCE AND
TROUBLESHOOTING
7.1. Maintenance plan
1. The PV component which requires more
often maintenance in a stand-alone PV
system is the:
a) PV panel
b) Battery
c) Inverter
2. The maintenance of the batteries depends
on:
a) The size of the batteries
b) The size of the PV system
c) The type, the charge/discharge cycles
and application of the batteries
3. The cleaning of the glass area of the
panels is typically done during midday
while the temperature is high.
a) True
b) False
4. Regarding the following tasks, choose the
ones not related to the performance
checks of the batteries:
a) Temperature measurements
b) Cell voltage readings
c) Module’s VOC
d) Capacity test
e) Specific gravity recordings
f) Inverter’s protections
5. Which type of battery requires the most
maintenance regarding water additions
and cleaning?
a) The flooded lead-antimony batteries
b) Sealed lead-acid batteries
6. Observing the LED indicators and displays
of the inverter is very important for the
appropriate maintenance of the inverter.
a) True
b) False
7. Pyranometer is used for the measurement
of the voltage and current at the DC and
AC side of the PV system.
a) True
b) False
8. In order to identify hot spots in a PV
system a ______can be used.
a) thermo- camera
b) voltmeter
c) polymeter
d) temperature -meter
9. During the maintenance of a PV system
observation for new shadings is not really
necessary.
a) True
b) False
7.2. Typical mistakes and failures
1. In order to minimize mistakes and faults in
a PV installation:
a) The most expensive equipment should
be selected
b) An appropriate and careful design is
needed
c) The PV installation should be inspected
once a month
2. When changing the array wiring layout,
the submitted electrical diagram shouldn’t
be changed.
a) True
b) False
PVTRIN Training course - Trainers Worksheet 58
3. During the wire installation, the cable ties
should be pulled too tight.
a) True
b) False
4. During the wire installation, multiple
cables can enter a single conductor cable
gland:
a) True
b) False
5. Which of the following is not an
installation mistake regarding module and
array grounding?
a) Connecting the different parts of the
modules together to achieve an equal
potential grounding
b) Using indoor-rated grounding lugs on PV
modules and support structures.
c) Assuming that simply bolting aluminium
frames to support structures provides
effective grounding.
d) Installing an undersized conductor for
grounding
e) Not install a properly protection for
lightning
6. Which of the following actions are
common installation mistakes with
electrical boxes, conduit bodies and
disconnecting means? (Choose 2 answers)
a. Installing disconnects rated for vertical
installation in a non-vertical
application.
b. Installing properly rated fuses in source
combiners and fused disconnects.
c. Letting boxes or conduit bodies to be
accessible for service.
d. Following manufacturer’s directions for
wiring disconnect in the DC side.
e. Installing dry wire nuts in wet locations
and inside boxes that get wet
routinely.
f. Using proper fittings to bring conductors
into exterior boxes.
7. Not using the correct roof adhesives for
the specific type of roof is a common
installation mistake with mounting
system.
a) True
b) False
8. When noticed that the batteries are not
charging, measuring the PV array open
circuit voltage and confirming that it is
within normal limits is the first task of
troubleshooting.
a) True
b) False
9. Match the typical failure to the corrective
measures and troubleshooting a) No current
from array
Check that no fuses are defective or
circuit breakers have been tripped.
(b)
b) Load not
operating
properly
Shorten cables or use heavier
cables, recharge battery, allow unit
to cool, improve air circulation,
locate unit to cooler environment.
(c)
c) Low
voltage
shutdown
Switch, fuse or circuit breaker open,
blown or tripped or wiring broken,
corroded.
Low voltage disconnect on inverter
or charge controller circuit is open,
High battery voltage. (f)
d) Reverse
Polarity
connection
on inverter
Switches, fuses, or circuit breakers
open, blown, tripped, wiring broken
or corroded (a)
e) Array fuse
blows
Some modules shaded, full sun not
available,
Array tilt or orientation incorrect,
Some modules damaged or
defective, Modules dirty (g)
f ) No output
from inverter
Array short circuit test performed
with battery connected.
Disconnect battery to perform test.
Array exceeds rating of controller,
add another controller in parallel if
appropriate or replace with
controller of higher capacity. (e)
PVTRIN Training course - Trainers Worksheet 59
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MORE EXERCISES AND
ACTIVITIES
g) Array
current low
Check connection to battery, the
inverter has likely been damaged
and needs to be replaced. (d)
7.3. Diagnostic procedures
1. A clear display gives added value to the
system.
a) True
b) False
2. The only data acquisition system is the
computer.
a) True
b) False
3. There is no limitation to the inputs that
may be monitored for a PV System
a) True
b) False
4. Telephonic transmission is often used as it
gives the opportunity for frequent
downloading of the PV system data.
a) True
b) False
5. If you are comparing two bar graphs of
monthly energy outputs of two different
years and there is a significant difference
between them, the reason could be:
a) a PV component failure
b) different weather condition for the two
years during that month
c) either a) or/and b)
7.4. Documentation to the
customer
1. A copy of the commissioning report
should be given to the owner together
with relevant conformity certificates and
guarantees.
a) True
b) False
7.5. Maintenance checklist
1. During a PV inspection, if the maintenance
list contains the following checks and
tests, please provide the correct PV part
they are referring to?
i. Terminals protected from shorting
ii.Cables properly terminated (no set screw
lugs on fine stranded wire)
iii. Maintenance-free vented for cooling
iv. Flooded vented to outside
a) DC connections,
b) Batteries,
c) Charge controllers,
d) Inverters,
e) Other PV part
8. QUALITY MANAGEMENT
AND CUSTOMER CARE
No exercises
PVTRIN Training course - Trainers Worksheet 60
LIST OF TABLES
TABLE 1. INDICATIVE MONTHLY VALUES 2
TABLE 2. HOUR ANGLE ω 3
TABLE 3. RESULTS OF EXERCISE 1 4
TABLE 4. APPLIANCES AND DAILY ENERGY
REQUIREMENTS 6
TABLE 5. PV -MODULE CHARACTERISTICS 7
TABLE 6. INVERTER CHARACTERISTICS 8
LIST OF FIGURES
FIGURE 1. SOLAR DECLINATION, δ 2
FIGURE 2. SOLAR ALTITUDE ANGLE, a 3
PVTRIN Training course - Trainers Worksheet 61
ACKNOWLEDGEMENTS
This Installers handbook was published within the framework of the PVTRIN project, supported by the Intelligent
Energy - Europe (IEE) programme.
The project steering committee members are:
Dr. Theocharis Tsoutsos (TUC/ENV, GR), Dr. Eduardo Román (TECNALIA, ES), Dave Richardson (BRE, UK), Gaetan
Masson (EPIA, EU-BE), Goran Granić (EIHP, HR), Christos Maxoulis (ETEK, CY), Ing. Camelia Rata (ABMEE, RO),
Antonis Pittaridakis (TEE, GR) and Violetta Groseva (SEC, BU).
The authors and the whole project consortium are deeply grateful to all those who have contributed with their
work in preparing, writing and reviewing this publication. Furthermore, we would like to express our thanks to the
Executive Agency for Competitiveness and Innovation (EACI) for their support.
AUTHORS: Ms. Ana Huidobro and Dr. Eduardo Román (TECNALIA), Dr. Theocharis Tsoutsos, Ms. Stavroula
Tournaki, Mr. Zacharias Gkouskos (ENV/TUC), Eleni Despotou, Gaëtan Masson, Pieterjan Vanbuggenhout and
Manoël Rekinger (EPIA), Dr. John Holden and Ms. Kim Noonam(BRE), Goran Grani and Andro Bačan (EIHP), Christos
Maxouli and Anthi Charalambous (ETEK), Antonis Pittaridakis and Dr.Charalambos Litos (TEE), Ing. Camelia Rata,
Leea Catincescu and Radu Gaspar (ABMEE), Mrs. Evelina Stoykova and Mrs. Violetta Groseva (SEC)
PHOTOGRAPHS ACKNOWLEDGMENTS to
A great deal of additional information on the PVTRIN project is available on the web at: www.pvtrin.eu.
We would welcome feedback on this publication, if you have comments or questions please contact the project
coordinator.
Legal Notice:
The sole responsibility for the content of this document lies with the authors. It does not necessarily reflect the opinion of the
European Union. Neither the EACI nor European Commission are responsible for any use that may be made of the information
contained therein
Tecnalia
PVTRIN PARTNERS
C E R T I F I E D I N S T A L L E R
Technical University of CreteEnvironmental Engineering Dpt.Renewable and Sustainable Energy Systems LabPROJECT COORDINATOR
Agency of Brasov for the Management of Energy and Environment
Building Research Establishment Ltd
Energy Institute Hrvoje Požar
European Photovoltaic Industry Association
Scientific and Technical Chamber of Cyprus
Sofia Energy Centre
Tecnalia
Technical Chamber of GreeceBranch of Western Crete
Partner Country Website
Greece
Romania
UK
Croatia
EU/ Belgium
Cyprus
Bulgaria
Spain
Greece
www.resel.tuc.gr
www.abmee.ro
www.bre.co.uk
www.eihp.hr
www.epia.org
www.etek.org.cy
www.sec.bg
www.tecnalia.com
www.teetdk.gr
www.pvtrin.eu
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