57101-11 INTRODUCTION TO SOLAR PHOTOVOLTAICS COMPREHENSIVE
EXAM Q&A - VERIFIED ANSWERS - LATEST EDITION - COMPLETE RESOURCE
(2026/2027)
1. What is solar photovoltaic (PV) energy? Solar photovoltaic energy is the
direct conversion of sunlight into electricity using semiconductor materials that
exhibit the photovoltaic effect.
2. What is the photovoltaic effect? The photovoltaic effect is the generation of
voltage and electric current in a material upon exposure to light, discovered by
Alexandre Edmond Becquerel in 1839.
3. What is solar irradiance? Solar irradiance is the power per unit area
received from the Sun in the form of electromagnetic radiation, typically
measured in watts per square meter (W/m²).
4. What is the solar constant? The solar constant is approximately 1367 W/m²,
representing the amount of solar electromagnetic radiation per unit area
received at the top of Earth's atmosphere.
5. What are the main components of solar radiation? Solar radiation consists
of direct radiation (beam radiation), diffuse radiation (scattered by atmosphere),
and reflected radiation (albedo).
6. What is Air Mass (AM)? Air Mass is the ratio of the path length of solar
radiation through the atmosphere to the vertical path length when the sun is
directly overhead. AM1.5 is the standard test condition.
7. What is peak sun hours? Peak sun hours represent the equivalent number of
hours per day when solar irradiance averages 1000 W/m², used to estimate daily
solar energy availability.
8. What is the difference between kW and kWh? kW (kilowatt) is a unit of
power (rate of energy use), while kWh (kilowatt-hour) is a unit of energy
(power used over time).
9. What is insolation? Insolation is the amount of solar radiation energy
received on a given surface area during a given time, typically expressed in
kWh/m²/day.
,10. How does latitude affect solar energy availability? Latitude affects the
angle at which sunlight strikes the Earth's surface and the length of daylight
hours, with locations closer to the equator generally receiving more solar
energy.
11. What is the sun path diagram? A sun path diagram is a graphical
representation showing the sun's trajectory across the sky throughout the year
for a specific location.
12. What is solar azimuth angle? Solar azimuth angle is the horizontal angle
measured clockwise from true north to the projection of the sun's position on the
horizontal plane.
13. What is solar altitude angle? Solar altitude angle (or solar elevation angle)
is the angle between the horizontal plane and the sun's position in the sky.
14. What is the solar declination angle? Solar declination angle is the angle
between the sun's rays and the plane of the Earth's equator, varying between
+23.45° and -23.45° throughout the year.
15. What is the tilt angle of a solar panel? The tilt angle is the angle between
the solar panel surface and the horizontal ground surface, optimized to
maximize annual energy production.
16. What is the optimal tilt angle for a fixed solar array? For fixed arrays,
the optimal tilt angle is approximately equal to the site's latitude for maximum
annual energy production.
17. What are the main advantages of solar energy? Advantages include
renewable nature, zero emissions during operation, low maintenance, silent
operation, scalability, and decreasing costs.
18. What are the main disadvantages of solar energy? Disadvantages include
intermittent generation, weather dependency, initial cost, space requirements,
and energy storage challenges.
19. What is capacity factor for solar PV? Capacity factor is the ratio of actual
energy produced to the maximum possible energy if the system operated at full
capacity continuously, typically 15-25% for solar PV.
20. What is the difference between on-grid and off-grid solar systems? On-
grid systems are connected to the utility grid and can export excess power,
while off-grid systems operate independently with battery storage.
, 21. What is net metering? Net metering is a billing mechanism that credits
solar system owners for electricity they add to the grid, offsetting their
consumption.
22. What is the duck curve? The duck curve illustrates the timing mismatch
between solar energy generation (peak midday) and electricity demand (peak
evening), creating grid management challenges.
23. What is solar tracking? Solar tracking involves moving solar panels to
follow the sun's path across the sky, increasing energy capture by 25-45%
compared to fixed systems.
24. What are single-axis and dual-axis tracking? Single-axis tracking rotates
on one axis (usually east-west), while dual-axis tracking adjusts both tilt and
azimuth for maximum sun exposure.
25. What is the levelized cost of energy (LCOE)? LCOE is the average cost
per unit of electricity generated over a system's lifetime, accounting for all costs
and energy production.
Section 2: Solar Cell Physics and Materials (Questions 26-50)
26. What is a solar cell? A solar cell is a semiconductor device that converts
light energy directly into electrical energy through the photovoltaic effect.
27. What are the main types of solar cells? Main types include
monocrystalline silicon, polycrystalline silicon, thin-film (amorphous silicon,
CdTe, CIGS), and emerging technologies (perovskite, organic).
28. What is a semiconductor? A semiconductor is a material with electrical
conductivity between that of a conductor and an insulator, whose conductivity
can be modified by doping.
29. What is the band gap? The band gap is the energy difference between the
valence band and conduction band in a semiconductor, determining which
wavelengths of light can be absorbed.
30. What is the ideal band gap for solar cells? The optimal band gap is
approximately 1.1-1.4 eV, with silicon at 1.12 eV being near ideal for solar
energy conversion.
31. What is p-type silicon? P-type silicon is silicon doped with acceptor
impurities (like boron) that create positive charge carriers (holes).
EXAM Q&A - VERIFIED ANSWERS - LATEST EDITION - COMPLETE RESOURCE
(2026/2027)
1. What is solar photovoltaic (PV) energy? Solar photovoltaic energy is the
direct conversion of sunlight into electricity using semiconductor materials that
exhibit the photovoltaic effect.
2. What is the photovoltaic effect? The photovoltaic effect is the generation of
voltage and electric current in a material upon exposure to light, discovered by
Alexandre Edmond Becquerel in 1839.
3. What is solar irradiance? Solar irradiance is the power per unit area
received from the Sun in the form of electromagnetic radiation, typically
measured in watts per square meter (W/m²).
4. What is the solar constant? The solar constant is approximately 1367 W/m²,
representing the amount of solar electromagnetic radiation per unit area
received at the top of Earth's atmosphere.
5. What are the main components of solar radiation? Solar radiation consists
of direct radiation (beam radiation), diffuse radiation (scattered by atmosphere),
and reflected radiation (albedo).
6. What is Air Mass (AM)? Air Mass is the ratio of the path length of solar
radiation through the atmosphere to the vertical path length when the sun is
directly overhead. AM1.5 is the standard test condition.
7. What is peak sun hours? Peak sun hours represent the equivalent number of
hours per day when solar irradiance averages 1000 W/m², used to estimate daily
solar energy availability.
8. What is the difference between kW and kWh? kW (kilowatt) is a unit of
power (rate of energy use), while kWh (kilowatt-hour) is a unit of energy
(power used over time).
9. What is insolation? Insolation is the amount of solar radiation energy
received on a given surface area during a given time, typically expressed in
kWh/m²/day.
,10. How does latitude affect solar energy availability? Latitude affects the
angle at which sunlight strikes the Earth's surface and the length of daylight
hours, with locations closer to the equator generally receiving more solar
energy.
11. What is the sun path diagram? A sun path diagram is a graphical
representation showing the sun's trajectory across the sky throughout the year
for a specific location.
12. What is solar azimuth angle? Solar azimuth angle is the horizontal angle
measured clockwise from true north to the projection of the sun's position on the
horizontal plane.
13. What is solar altitude angle? Solar altitude angle (or solar elevation angle)
is the angle between the horizontal plane and the sun's position in the sky.
14. What is the solar declination angle? Solar declination angle is the angle
between the sun's rays and the plane of the Earth's equator, varying between
+23.45° and -23.45° throughout the year.
15. What is the tilt angle of a solar panel? The tilt angle is the angle between
the solar panel surface and the horizontal ground surface, optimized to
maximize annual energy production.
16. What is the optimal tilt angle for a fixed solar array? For fixed arrays,
the optimal tilt angle is approximately equal to the site's latitude for maximum
annual energy production.
17. What are the main advantages of solar energy? Advantages include
renewable nature, zero emissions during operation, low maintenance, silent
operation, scalability, and decreasing costs.
18. What are the main disadvantages of solar energy? Disadvantages include
intermittent generation, weather dependency, initial cost, space requirements,
and energy storage challenges.
19. What is capacity factor for solar PV? Capacity factor is the ratio of actual
energy produced to the maximum possible energy if the system operated at full
capacity continuously, typically 15-25% for solar PV.
20. What is the difference between on-grid and off-grid solar systems? On-
grid systems are connected to the utility grid and can export excess power,
while off-grid systems operate independently with battery storage.
, 21. What is net metering? Net metering is a billing mechanism that credits
solar system owners for electricity they add to the grid, offsetting their
consumption.
22. What is the duck curve? The duck curve illustrates the timing mismatch
between solar energy generation (peak midday) and electricity demand (peak
evening), creating grid management challenges.
23. What is solar tracking? Solar tracking involves moving solar panels to
follow the sun's path across the sky, increasing energy capture by 25-45%
compared to fixed systems.
24. What are single-axis and dual-axis tracking? Single-axis tracking rotates
on one axis (usually east-west), while dual-axis tracking adjusts both tilt and
azimuth for maximum sun exposure.
25. What is the levelized cost of energy (LCOE)? LCOE is the average cost
per unit of electricity generated over a system's lifetime, accounting for all costs
and energy production.
Section 2: Solar Cell Physics and Materials (Questions 26-50)
26. What is a solar cell? A solar cell is a semiconductor device that converts
light energy directly into electrical energy through the photovoltaic effect.
27. What are the main types of solar cells? Main types include
monocrystalline silicon, polycrystalline silicon, thin-film (amorphous silicon,
CdTe, CIGS), and emerging technologies (perovskite, organic).
28. What is a semiconductor? A semiconductor is a material with electrical
conductivity between that of a conductor and an insulator, whose conductivity
can be modified by doping.
29. What is the band gap? The band gap is the energy difference between the
valence band and conduction band in a semiconductor, determining which
wavelengths of light can be absorbed.
30. What is the ideal band gap for solar cells? The optimal band gap is
approximately 1.1-1.4 eV, with silicon at 1.12 eV being near ideal for solar
energy conversion.
31. What is p-type silicon? P-type silicon is silicon doped with acceptor
impurities (like boron) that create positive charge carriers (holes).
