2026 VA Alternative Energy System
Contracting 1-120
Question 1: What is the primary function of a photovoltaic cell in a solar energy
system?
Option A: Convert sunlight into electricity
Option B: Store electrical energy
Option C: Regulate current flow
Option D: Step-up voltage -Answer--Correct Answer: A - Convert sunlight into
electricity
Explanation: Photovoltaic cells convert sunlight directly into electrical energy via the
photovoltaic effect.
Question 2: Which photovoltaic technology is known for its high efficiency and
longevity?
Option A: Thin-film
Option B: Polycrystalline
Option C: Monocrystalline
Option D: Amorphous silicon -Answer--Correct Answer: C - Monocrystalline
Explanation: Monocrystalline silicon cells have high efficiency and durability, making
them a preferred choice in many installations.
Question 3: In a solar system design, what is the role of an inverter?
Option A: To store energy
Option B: To convert DC to AC power
Option C: To track the sun
Option D: To increase voltage -Answer--Correct Answer: B - To convert DC to AC
power
Explanation: The inverter converts the direct current (DC) produced by PV panels
into alternating current (AC) used by most appliances.
,Question 4: What does MPPT stand for in photovoltaic systems?
Option A: Maximum Power Point Technique
Option B: Maximum Power Phase Tracker
Option C: Maximum Power Point Tracking
Option D: Minimum Power Phase Tracker -Answer--Correct Answer: C - Maximum
Power Point Tracking
Explanation: MPPT is a method used by inverters to maximize power extraction
under varying conditions.
Question 5: Which factor primarily affects the output efficiency of a PV cell?
Option A: Ambient temperature
Option B: Wind speed
Option C: Altitude
Option D: Humidity -Answer--Correct Answer: A - Ambient temperature
Explanation: Higher temperatures can decrease the efficiency of PV cells, making
temperature a key factor in performance.
Question 6: What is the typical voltage range of a standard PV module under load?
Option A: 12-24 V
Option B: 24-48 V
Option C: 30-40 V
Option D: 15-20 V -Answer--Correct Answer: B - 24-48 V
Explanation: Most standard PV modules are designed to operate in the 24-48 V
range for optimal performance in residential systems.
Question 7: Which installation aspect ensures that a solar array is safely connected
to the building's grounding system?
Option A: DC disconnect
Option B: Overcurrent protection
Option C: Grounding and bonding
Option D: Charge controller -Answer--Correct Answer: C - Grounding and bonding
Explanation: Proper grounding and bonding protect the system and personnel from
electrical faults and lightning strikes.
Question 8: In system design, what does the term "string sizing" refer to?
,Option A: Connecting multiple PV modules in series
Option B: Wiring panels in parallel
Option C: Choosing the correct inverter
Option D: Matching battery capacity -Answer--Correct Answer: A - Connecting
multiple PV modules in series
Explanation: String sizing involves determining the number of modules to connect in
series to achieve a desired voltage.
Question 9: When calculating the energy production of a PV system, which unit is
most commonly used?
Option A: Watts (W)
Option B: Kilowatt-hours (kWh)
Option C: Amperes (A)
Option D: Volts (V) -Answer--Correct Answer: B - Kilowatt-hours (kWh)
Explanation: Kilowatt-hours (kWh) measure energy production over time, which is
essential for system yield estimates.
Question 10: What is one of the key advantages of using thin-film PV technology?
Option A: Highest efficiency
Option B: Flexibility and light weight
Option C: Long operational life
Option D: High temperature tolerance -Answer--Correct Answer: B - Flexibility and
light weight
Explanation: Thin-film PV panels are known for their flexibility, making them suitable
for curved surfaces and lighter installations.
Question 11: Which component is critical for preventing overcharging in a solar
energy system with battery storage?
Option A: Inverter
Option B: MPPT controller
Option C: Charge controller
Option D: DC disconnect -Answer--Correct Answer: C - Charge controller
Explanation: The charge controller regulates the energy flowing to the batteries,
preventing overcharge and extending battery life.
Question 12: What calculation is essential when determining the wiring size in a
photovoltaic installation?
, Option A: Load factor
Option B: Voltage drop calculation
Option C: Inverter efficiency
Option D: String configuration -Answer--Correct Answer: B - Voltage drop calculation
Explanation: Calculating voltage drop ensures that wiring is appropriately sized to
minimize energy loss over distance.
Question 13: Which factor is most important when estimating a solar system's cost?
Option A: Roof color
Option B: System efficiency
Option C: Module degradation rate
Option D: Local solar irradiance -Answer--Correct Answer: D - Local solar irradiance
Explanation: Local solar irradiance directly impacts energy production estimates and
system cost-effectiveness.
Question 14: What does the term "DC disconnect" refer to in PV systems?
Option A: A device that converts AC to DC
Option B: A safety switch to isolate the DC circuits
Option C: A method to reduce DC voltage
Option D: A tool to measure direct current -Answer--Correct Answer: B - A safety
switch to isolate the DC circuits
Explanation: A DC disconnect allows safe maintenance by isolating the DC portion of
the system during service.
Question 15: Which of the following is a typical challenge when installing rooftop PV
systems?
Option A: Low solar irradiance
Option B: Shading and roof orientation
Option C: Excessive battery storage
Option D: Too much wind -Answer--Correct Answer: B - Shading and roof orientation
Explanation: Shading and roof orientation critically affect the performance and
design of rooftop solar systems.
Question 16: How is the overall efficiency of a photovoltaic module determined?
Option A: Ratio of AC output to battery capacity
Contracting 1-120
Question 1: What is the primary function of a photovoltaic cell in a solar energy
system?
Option A: Convert sunlight into electricity
Option B: Store electrical energy
Option C: Regulate current flow
Option D: Step-up voltage -Answer--Correct Answer: A - Convert sunlight into
electricity
Explanation: Photovoltaic cells convert sunlight directly into electrical energy via the
photovoltaic effect.
Question 2: Which photovoltaic technology is known for its high efficiency and
longevity?
Option A: Thin-film
Option B: Polycrystalline
Option C: Monocrystalline
Option D: Amorphous silicon -Answer--Correct Answer: C - Monocrystalline
Explanation: Monocrystalline silicon cells have high efficiency and durability, making
them a preferred choice in many installations.
Question 3: In a solar system design, what is the role of an inverter?
Option A: To store energy
Option B: To convert DC to AC power
Option C: To track the sun
Option D: To increase voltage -Answer--Correct Answer: B - To convert DC to AC
power
Explanation: The inverter converts the direct current (DC) produced by PV panels
into alternating current (AC) used by most appliances.
,Question 4: What does MPPT stand for in photovoltaic systems?
Option A: Maximum Power Point Technique
Option B: Maximum Power Phase Tracker
Option C: Maximum Power Point Tracking
Option D: Minimum Power Phase Tracker -Answer--Correct Answer: C - Maximum
Power Point Tracking
Explanation: MPPT is a method used by inverters to maximize power extraction
under varying conditions.
Question 5: Which factor primarily affects the output efficiency of a PV cell?
Option A: Ambient temperature
Option B: Wind speed
Option C: Altitude
Option D: Humidity -Answer--Correct Answer: A - Ambient temperature
Explanation: Higher temperatures can decrease the efficiency of PV cells, making
temperature a key factor in performance.
Question 6: What is the typical voltage range of a standard PV module under load?
Option A: 12-24 V
Option B: 24-48 V
Option C: 30-40 V
Option D: 15-20 V -Answer--Correct Answer: B - 24-48 V
Explanation: Most standard PV modules are designed to operate in the 24-48 V
range for optimal performance in residential systems.
Question 7: Which installation aspect ensures that a solar array is safely connected
to the building's grounding system?
Option A: DC disconnect
Option B: Overcurrent protection
Option C: Grounding and bonding
Option D: Charge controller -Answer--Correct Answer: C - Grounding and bonding
Explanation: Proper grounding and bonding protect the system and personnel from
electrical faults and lightning strikes.
Question 8: In system design, what does the term "string sizing" refer to?
,Option A: Connecting multiple PV modules in series
Option B: Wiring panels in parallel
Option C: Choosing the correct inverter
Option D: Matching battery capacity -Answer--Correct Answer: A - Connecting
multiple PV modules in series
Explanation: String sizing involves determining the number of modules to connect in
series to achieve a desired voltage.
Question 9: When calculating the energy production of a PV system, which unit is
most commonly used?
Option A: Watts (W)
Option B: Kilowatt-hours (kWh)
Option C: Amperes (A)
Option D: Volts (V) -Answer--Correct Answer: B - Kilowatt-hours (kWh)
Explanation: Kilowatt-hours (kWh) measure energy production over time, which is
essential for system yield estimates.
Question 10: What is one of the key advantages of using thin-film PV technology?
Option A: Highest efficiency
Option B: Flexibility and light weight
Option C: Long operational life
Option D: High temperature tolerance -Answer--Correct Answer: B - Flexibility and
light weight
Explanation: Thin-film PV panels are known for their flexibility, making them suitable
for curved surfaces and lighter installations.
Question 11: Which component is critical for preventing overcharging in a solar
energy system with battery storage?
Option A: Inverter
Option B: MPPT controller
Option C: Charge controller
Option D: DC disconnect -Answer--Correct Answer: C - Charge controller
Explanation: The charge controller regulates the energy flowing to the batteries,
preventing overcharge and extending battery life.
Question 12: What calculation is essential when determining the wiring size in a
photovoltaic installation?
, Option A: Load factor
Option B: Voltage drop calculation
Option C: Inverter efficiency
Option D: String configuration -Answer--Correct Answer: B - Voltage drop calculation
Explanation: Calculating voltage drop ensures that wiring is appropriately sized to
minimize energy loss over distance.
Question 13: Which factor is most important when estimating a solar system's cost?
Option A: Roof color
Option B: System efficiency
Option C: Module degradation rate
Option D: Local solar irradiance -Answer--Correct Answer: D - Local solar irradiance
Explanation: Local solar irradiance directly impacts energy production estimates and
system cost-effectiveness.
Question 14: What does the term "DC disconnect" refer to in PV systems?
Option A: A device that converts AC to DC
Option B: A safety switch to isolate the DC circuits
Option C: A method to reduce DC voltage
Option D: A tool to measure direct current -Answer--Correct Answer: B - A safety
switch to isolate the DC circuits
Explanation: A DC disconnect allows safe maintenance by isolating the DC portion of
the system during service.
Question 15: Which of the following is a typical challenge when installing rooftop PV
systems?
Option A: Low solar irradiance
Option B: Shading and roof orientation
Option C: Excessive battery storage
Option D: Too much wind -Answer--Correct Answer: B - Shading and roof orientation
Explanation: Shading and roof orientation critically affect the performance and
design of rooftop solar systems.
Question 16: How is the overall efficiency of a photovoltaic module determined?
Option A: Ratio of AC output to battery capacity
