PV 101: BASIC PHOTOVOLTAICS UPDATED EXAM QUESTIONS AND
VERIFIED SOLUTIONS (2026/2027)
1. What is photovoltaics? Photovoltaics is the direct conversion of light energy
into electrical energy using semiconductor materials.
2. What does PV stand for? PV stands for Photovoltaic.
3. What is the photovoltaic effect? The photovoltaic effect is the creation of
voltage or electric current in a material upon exposure to light.
4. Who discovered the photovoltaic effect? French physicist Alexandre
Edmond Becquerel discovered the photovoltaic effect in 1839.
5. What is solar irradiance? Solar irradiance is the power per unit area
received from the Sun in the form of electromagnetic radiation, measured in
watts per square meter (W/m²).
6. What is the solar constant? The solar constant is approximately 1,367
W/m², representing the amount of solar electromagnetic radiation per unit area
at Earth's distance from the Sun.
7. What is AM1.5? AM1.5 (Air Mass 1.5) is the standard spectrum used for
testing solar cells, representing sunlight after passing through 1.5 times the
thickness of Earth's atmosphere at a 48.2° angle.
8. What does STC stand for in solar testing? STC stands for Standard Test
Conditions, which includes 1,000 W/m² irradiance, 25°C cell temperature, and
AM1.5 spectrum.
9. What is insolation? Insolation is the amount of solar radiation energy
received on a given surface area during a given time, typically measured in
kWh/m²/day.
10. What is peak sun hours? Peak sun hours represent the equivalent number
of hours per day when solar irradiance averages 1,000 W/m².
11. What wavelengths of light can solar cells convert? Most silicon solar
cells can convert light wavelengths from approximately 300 nm to 1,100 nm.
,12. What is the difference between solar thermal and photovoltaic? Solar
thermal uses sunlight to produce heat, while photovoltaic directly converts
sunlight into electricity.
13. What is albedo in solar energy? Albedo is the measure of reflectivity of a
surface, affecting how much sunlight is reflected versus absorbed.
14. What is direct normal irradiance (DNI)? DNI is the amount of solar
radiation received per unit area by a surface perpendicular to the sun's rays.
15. What is diffuse horizontal irradiance (DHI)? DHI is solar radiation
received from the sky (excluding direct solar radiation) on a horizontal surface.
16. What is global horizontal irradiance (GHI)? GHI is the total solar
radiation received on a horizontal surface, combining both direct and diffuse
radiation.
17. Why is solar energy considered renewable? Solar energy is renewable
because the sun continuously produces energy and will do so for billions of
years.
18. What percentage of Earth's energy needs could theoretically be met by
solar? The sun provides more than enough energy to meet all of Earth's energy
needs many times over, with one hour of sunlight theoretically meeting annual
global energy demand.
19. What is the Zenith angle? The Zenith angle is the angle between the sun's
rays and a vertical line perpendicular to the ground.
20. What is solar azimuth? Solar azimuth is the angle of the sun's position
relative to true north measured in the horizontal plane.
21. What affects solar panel performance? Temperature, shading, orientation,
tilt angle, soiling, and atmospheric conditions all affect solar panel performance.
22. Why do solar panels produce less power on hot days? Solar panels lose
efficiency as temperature increases because heat increases electrical resistance
in the semiconductor material.
23. What is the advantage of solar energy? Solar energy is clean, renewable,
abundant, requires minimal maintenance, and produces no greenhouse gas
emissions during operation.
24. What are the main disadvantages of solar energy? High initial costs,
intermittency, weather dependence, space requirements, and energy storage
challenges.
, 25. What is capacity factor in solar energy? Capacity factor is the ratio of
actual energy produced to the maximum possible energy production if operating
at full capacity continuously.
SECTION 2: SEMICONDUCTOR PHYSICS (Questions 26-50)
26. What is a semiconductor? A semiconductor is a material with electrical
conductivity between that of a conductor and an insulator, typically silicon or
germanium.
27. Why is silicon used in most solar cells? Silicon is abundant, has suitable
bandgap energy, is stable, well-understood, and cost-effective for solar cell
production.
28. What is a bandgap? The bandgap is the energy difference between the
valence band and conduction band in a semiconductor material.
29. What is the bandgap of crystalline silicon? Crystalline silicon has a
bandgap of approximately 1.12 eV (electron volts).
30. What are valence electrons? Valence electrons are the electrons in the
outermost shell of an atom that participate in chemical bonding.
31. What is the conduction band? The conduction band is the energy level in
a semiconductor where electrons are free to move and conduct electricity.
32. What is the valence band? The valence band is the highest energy level in
a semiconductor where electrons are bound to atoms.
33. What is an electron-hole pair? An electron-hole pair is created when a
photon excites an electron from the valence band to the conduction band,
leaving behind a positively charged "hole."
34. What is doping in semiconductors? Doping is the intentional introduction
of impurities into a semiconductor to modify its electrical properties.
35. What is n-type silicon? N-type silicon is doped with elements like
phosphorus that provide extra electrons, making it negatively charged.
36. What is p-type silicon? P-type silicon is doped with elements like boron
that create "holes" or positive charge carriers.
37. What dopant is commonly used for n-type silicon? Phosphorus is the
most common dopant for n-type silicon.
VERIFIED SOLUTIONS (2026/2027)
1. What is photovoltaics? Photovoltaics is the direct conversion of light energy
into electrical energy using semiconductor materials.
2. What does PV stand for? PV stands for Photovoltaic.
3. What is the photovoltaic effect? The photovoltaic effect is the creation of
voltage or electric current in a material upon exposure to light.
4. Who discovered the photovoltaic effect? French physicist Alexandre
Edmond Becquerel discovered the photovoltaic effect in 1839.
5. What is solar irradiance? Solar irradiance is the power per unit area
received from the Sun in the form of electromagnetic radiation, measured in
watts per square meter (W/m²).
6. What is the solar constant? The solar constant is approximately 1,367
W/m², representing the amount of solar electromagnetic radiation per unit area
at Earth's distance from the Sun.
7. What is AM1.5? AM1.5 (Air Mass 1.5) is the standard spectrum used for
testing solar cells, representing sunlight after passing through 1.5 times the
thickness of Earth's atmosphere at a 48.2° angle.
8. What does STC stand for in solar testing? STC stands for Standard Test
Conditions, which includes 1,000 W/m² irradiance, 25°C cell temperature, and
AM1.5 spectrum.
9. What is insolation? Insolation is the amount of solar radiation energy
received on a given surface area during a given time, typically measured in
kWh/m²/day.
10. What is peak sun hours? Peak sun hours represent the equivalent number
of hours per day when solar irradiance averages 1,000 W/m².
11. What wavelengths of light can solar cells convert? Most silicon solar
cells can convert light wavelengths from approximately 300 nm to 1,100 nm.
,12. What is the difference between solar thermal and photovoltaic? Solar
thermal uses sunlight to produce heat, while photovoltaic directly converts
sunlight into electricity.
13. What is albedo in solar energy? Albedo is the measure of reflectivity of a
surface, affecting how much sunlight is reflected versus absorbed.
14. What is direct normal irradiance (DNI)? DNI is the amount of solar
radiation received per unit area by a surface perpendicular to the sun's rays.
15. What is diffuse horizontal irradiance (DHI)? DHI is solar radiation
received from the sky (excluding direct solar radiation) on a horizontal surface.
16. What is global horizontal irradiance (GHI)? GHI is the total solar
radiation received on a horizontal surface, combining both direct and diffuse
radiation.
17. Why is solar energy considered renewable? Solar energy is renewable
because the sun continuously produces energy and will do so for billions of
years.
18. What percentage of Earth's energy needs could theoretically be met by
solar? The sun provides more than enough energy to meet all of Earth's energy
needs many times over, with one hour of sunlight theoretically meeting annual
global energy demand.
19. What is the Zenith angle? The Zenith angle is the angle between the sun's
rays and a vertical line perpendicular to the ground.
20. What is solar azimuth? Solar azimuth is the angle of the sun's position
relative to true north measured in the horizontal plane.
21. What affects solar panel performance? Temperature, shading, orientation,
tilt angle, soiling, and atmospheric conditions all affect solar panel performance.
22. Why do solar panels produce less power on hot days? Solar panels lose
efficiency as temperature increases because heat increases electrical resistance
in the semiconductor material.
23. What is the advantage of solar energy? Solar energy is clean, renewable,
abundant, requires minimal maintenance, and produces no greenhouse gas
emissions during operation.
24. What are the main disadvantages of solar energy? High initial costs,
intermittency, weather dependence, space requirements, and energy storage
challenges.
, 25. What is capacity factor in solar energy? Capacity factor is the ratio of
actual energy produced to the maximum possible energy production if operating
at full capacity continuously.
SECTION 2: SEMICONDUCTOR PHYSICS (Questions 26-50)
26. What is a semiconductor? A semiconductor is a material with electrical
conductivity between that of a conductor and an insulator, typically silicon or
germanium.
27. Why is silicon used in most solar cells? Silicon is abundant, has suitable
bandgap energy, is stable, well-understood, and cost-effective for solar cell
production.
28. What is a bandgap? The bandgap is the energy difference between the
valence band and conduction band in a semiconductor material.
29. What is the bandgap of crystalline silicon? Crystalline silicon has a
bandgap of approximately 1.12 eV (electron volts).
30. What are valence electrons? Valence electrons are the electrons in the
outermost shell of an atom that participate in chemical bonding.
31. What is the conduction band? The conduction band is the energy level in
a semiconductor where electrons are free to move and conduct electricity.
32. What is the valence band? The valence band is the highest energy level in
a semiconductor where electrons are bound to atoms.
33. What is an electron-hole pair? An electron-hole pair is created when a
photon excites an electron from the valence band to the conduction band,
leaving behind a positively charged "hole."
34. What is doping in semiconductors? Doping is the intentional introduction
of impurities into a semiconductor to modify its electrical properties.
35. What is n-type silicon? N-type silicon is doped with elements like
phosphorus that provide extra electrons, making it negatively charged.
36. What is p-type silicon? P-type silicon is doped with elements like boron
that create "holes" or positive charge carriers.
37. What dopant is commonly used for n-type silicon? Phosphorus is the
most common dopant for n-type silicon.
