SOLAR PV ULTIMATE EXAM - VERIFIED ANSWERS AND
QUESTIONS - MOST RECENT EDITION 2026
Q1: What does PV stand for in Solar PV?
A1: PV stands for Photovoltaic, which refers to the conversion of light into
electricity using semiconducting materials.
Q2: How does a solar PV cell work?
A2: Solar PV cells work through the photovoltaic effect, where photons from
sunlight knock electrons free from atoms in semiconductor material, creating an
electric current.
Q3: What is the most common material used in solar cells?
A3: Silicon is the most common material, used in about 95% of solar panels. It can
be monocrystalline, polycrystalline, or amorphous.
Q4: What is the difference between monocrystalline and polycrystalline solar
panels?
A4: Monocrystalline panels are made from single-crystal silicon and are more
efficient (18-22%) but more expensive. Polycrystalline panels are made from
multiple silicon crystals, are slightly less efficient (15-17%) but more affordable.
Q5: What are the main components of a solar PV system?
A5: The main components are: solar panels (modules), inverters, mounting
structures, wiring, and optionally battery storage and monitoring systems.
Q6: What is an inverter and why is it necessary?
A6: An inverter converts DC (direct current) electricity produced by solar panels
into AC (alternating current) electricity used by most home appliances and the
electrical grid.
Q7: What is peak sun hours?
,A7: Peak sun hours represent the equivalent number of hours per day when solar
irradiance averages 1,000 watts per square meter. It's used to estimate solar energy
production.
Q8: What is solar irradiance?
A8: 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).
Q9: What is the typical efficiency of commercial solar panels?
A9: Commercial solar panels typically have efficiencies between 15-22%, with
premium monocrystalline panels reaching up to 23%.
Q10: What factors affect solar panel efficiency?
A10: Key factors include: temperature (higher temps reduce efficiency), shading,
panel orientation and tilt, dust and dirt accumulation, age of panels, and quality of
materials.
Q11: What is the lifespan of a typical solar panel?
A11: Most solar panels have a lifespan of 25-30 years, with warranties typically
guaranteeing 80-90% performance after 25 years.
Q12: What is degradation rate in solar panels?
A12: Degradation rate is the annual percentage decrease in power output. Quality
panels typically degrade at 0.5-0.8% per year.
Q13: What is the difference between kW and kWh?
A13: kW (kilowatt) is a measure of power or capacity at a given moment. kWh
(kilowatt-hour) is a measure of energy over time - the amount of energy used or
generated over one hour.
Q14: What is STC in solar panel specifications?
A14: STC stands for Standard Test Conditions: 1,000 W/m² irradiance, 25°C cell
temperature, and air mass 1.5 spectrum. It's the standard for rating panel
performance.
Q15: What is NOCT?
A15: NOCT (Nominal Operating Cell Temperature) is the temperature a solar cell
reaches under 800 W/m² irradiance, 20°C ambient temperature, and 1 m/s wind
speed.
,Q16: What are thin-film solar panels?
A16: Thin-film solar panels are made by depositing photovoltaic material onto a
substrate. They're flexible, lightweight, and cheaper but less efficient (10-13%)
than crystalline silicon.
Q17: What is BIPV?
A17: BIPV (Building Integrated Photovoltaics) refers to solar materials integrated
into building components like roofs, facades, or windows, serving both as building
envelope and power generator.
Q18: What is the fill factor in solar cells?
A18: Fill factor is the ratio of maximum power to the product of open-circuit
voltage and short-circuit current. It's a measure of cell quality, typically 70-80%.
Q19: What is open-circuit voltage (Voc)?
A19: Voc is the maximum voltage a solar cell produces when no current is
flowing, measured when the circuit is open.
Q20: What is short-circuit current (Isc)?
A20: Isc is the maximum current a solar cell produces when the voltage across the
cell is zero, measured when the terminals are short-circuited.
Q21: What is maximum power point (MPP)?
A21: MPP is the operating point on the current-voltage curve where the product of
current and voltage is maximized, producing the highest power output.
Q22: What are bypass diodes?
A22: Bypass diodes are installed across groups of solar cells to allow current to
flow around shaded or damaged cells, preventing hot spots and power loss.
Q23: What is the temperature coefficient?
A23: The temperature coefficient indicates how much panel output decreases as
temperature rises above 25°C. Typical values are -0.3% to -0.5% per degree
Celsius.
Q24: What is a solar array?
A24: A solar array is a collection of multiple solar panels connected together to
generate electricity at a larger scale.
Q25: What is the difference between on-grid and off-grid systems?
, A25: On-grid systems are connected to the utility grid and can send excess power
back. Off-grid systems are standalone, typically requiring battery storage for
nighttime use.
Q26: What is net metering?
A26: Net metering is a billing mechanism that credits solar system owners for
electricity they add to the grid, offsetting power drawn when panels aren't
producing.
Q27: What are the different types of solar inverters?
A27: Main types are: string inverters (connect multiple panels), microinverters
(one per panel), and power optimizers (hybrid approach with module-level
optimization).
Q28: What is an MPPT charge controller?
A28: MPPT (Maximum Power Point Tracking) is a technology that optimizes the
match between solar array and battery bank, extracting maximum power under
varying conditions.
Q29: What is the albedo effect in solar energy?
A29: The albedo effect refers to additional solar radiation reflected from
surrounding surfaces (like snow or water) onto solar panels, increasing energy
production.
Q30: What is a solar tracker?
A30: A solar tracker is a device that orients solar panels toward the sun throughout
the day, increasing energy capture by 15-40% compared to fixed systems.
Section 2: System Design & Installation (Q31-Q60)
Q31: How do you calculate the required solar panel capacity for a home?
A31: Calculate average daily energy consumption (kWh), divide by peak sun hours
in your location, and account for system losses (typically 20-25%) to determine
required kW capacity.
Q32: What is the optimal tilt angle for solar panels?
A32: Optimal tilt typically equals the latitude of the location for year-round
production. It can be adjusted seasonally: latitude +15° in winter, latitude -15° in
summer.
QUESTIONS - MOST RECENT EDITION 2026
Q1: What does PV stand for in Solar PV?
A1: PV stands for Photovoltaic, which refers to the conversion of light into
electricity using semiconducting materials.
Q2: How does a solar PV cell work?
A2: Solar PV cells work through the photovoltaic effect, where photons from
sunlight knock electrons free from atoms in semiconductor material, creating an
electric current.
Q3: What is the most common material used in solar cells?
A3: Silicon is the most common material, used in about 95% of solar panels. It can
be monocrystalline, polycrystalline, or amorphous.
Q4: What is the difference between monocrystalline and polycrystalline solar
panels?
A4: Monocrystalline panels are made from single-crystal silicon and are more
efficient (18-22%) but more expensive. Polycrystalline panels are made from
multiple silicon crystals, are slightly less efficient (15-17%) but more affordable.
Q5: What are the main components of a solar PV system?
A5: The main components are: solar panels (modules), inverters, mounting
structures, wiring, and optionally battery storage and monitoring systems.
Q6: What is an inverter and why is it necessary?
A6: An inverter converts DC (direct current) electricity produced by solar panels
into AC (alternating current) electricity used by most home appliances and the
electrical grid.
Q7: What is peak sun hours?
,A7: Peak sun hours represent the equivalent number of hours per day when solar
irradiance averages 1,000 watts per square meter. It's used to estimate solar energy
production.
Q8: What is solar irradiance?
A8: 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).
Q9: What is the typical efficiency of commercial solar panels?
A9: Commercial solar panels typically have efficiencies between 15-22%, with
premium monocrystalline panels reaching up to 23%.
Q10: What factors affect solar panel efficiency?
A10: Key factors include: temperature (higher temps reduce efficiency), shading,
panel orientation and tilt, dust and dirt accumulation, age of panels, and quality of
materials.
Q11: What is the lifespan of a typical solar panel?
A11: Most solar panels have a lifespan of 25-30 years, with warranties typically
guaranteeing 80-90% performance after 25 years.
Q12: What is degradation rate in solar panels?
A12: Degradation rate is the annual percentage decrease in power output. Quality
panels typically degrade at 0.5-0.8% per year.
Q13: What is the difference between kW and kWh?
A13: kW (kilowatt) is a measure of power or capacity at a given moment. kWh
(kilowatt-hour) is a measure of energy over time - the amount of energy used or
generated over one hour.
Q14: What is STC in solar panel specifications?
A14: STC stands for Standard Test Conditions: 1,000 W/m² irradiance, 25°C cell
temperature, and air mass 1.5 spectrum. It's the standard for rating panel
performance.
Q15: What is NOCT?
A15: NOCT (Nominal Operating Cell Temperature) is the temperature a solar cell
reaches under 800 W/m² irradiance, 20°C ambient temperature, and 1 m/s wind
speed.
,Q16: What are thin-film solar panels?
A16: Thin-film solar panels are made by depositing photovoltaic material onto a
substrate. They're flexible, lightweight, and cheaper but less efficient (10-13%)
than crystalline silicon.
Q17: What is BIPV?
A17: BIPV (Building Integrated Photovoltaics) refers to solar materials integrated
into building components like roofs, facades, or windows, serving both as building
envelope and power generator.
Q18: What is the fill factor in solar cells?
A18: Fill factor is the ratio of maximum power to the product of open-circuit
voltage and short-circuit current. It's a measure of cell quality, typically 70-80%.
Q19: What is open-circuit voltage (Voc)?
A19: Voc is the maximum voltage a solar cell produces when no current is
flowing, measured when the circuit is open.
Q20: What is short-circuit current (Isc)?
A20: Isc is the maximum current a solar cell produces when the voltage across the
cell is zero, measured when the terminals are short-circuited.
Q21: What is maximum power point (MPP)?
A21: MPP is the operating point on the current-voltage curve where the product of
current and voltage is maximized, producing the highest power output.
Q22: What are bypass diodes?
A22: Bypass diodes are installed across groups of solar cells to allow current to
flow around shaded or damaged cells, preventing hot spots and power loss.
Q23: What is the temperature coefficient?
A23: The temperature coefficient indicates how much panel output decreases as
temperature rises above 25°C. Typical values are -0.3% to -0.5% per degree
Celsius.
Q24: What is a solar array?
A24: A solar array is a collection of multiple solar panels connected together to
generate electricity at a larger scale.
Q25: What is the difference between on-grid and off-grid systems?
, A25: On-grid systems are connected to the utility grid and can send excess power
back. Off-grid systems are standalone, typically requiring battery storage for
nighttime use.
Q26: What is net metering?
A26: Net metering is a billing mechanism that credits solar system owners for
electricity they add to the grid, offsetting power drawn when panels aren't
producing.
Q27: What are the different types of solar inverters?
A27: Main types are: string inverters (connect multiple panels), microinverters
(one per panel), and power optimizers (hybrid approach with module-level
optimization).
Q28: What is an MPPT charge controller?
A28: MPPT (Maximum Power Point Tracking) is a technology that optimizes the
match between solar array and battery bank, extracting maximum power under
varying conditions.
Q29: What is the albedo effect in solar energy?
A29: The albedo effect refers to additional solar radiation reflected from
surrounding surfaces (like snow or water) onto solar panels, increasing energy
production.
Q30: What is a solar tracker?
A30: A solar tracker is a device that orients solar panels toward the sun throughout
the day, increasing energy capture by 15-40% compared to fixed systems.
Section 2: System Design & Installation (Q31-Q60)
Q31: How do you calculate the required solar panel capacity for a home?
A31: Calculate average daily energy consumption (kWh), divide by peak sun hours
in your location, and account for system losses (typically 20-25%) to determine
required kW capacity.
Q32: What is the optimal tilt angle for solar panels?
A32: Optimal tilt typically equals the latitude of the location for year-round
production. It can be adjusted seasonally: latitude +15° in winter, latitude -15° in
summer.
