NABCEP PV System Design Principles 3

Question 1

The purpose of a module-level power electronics (MLPE) device such as a microinverter or DC optimizer is primarily to:

Accepted Answer

Mitigate the impact of shading and mismatch on overall system output

Answer

MLPEs allow each module to operate at its own maximum power point, reducing losses caused by shading, soiling, or module mismatch.

Question 2

For a roof-mounted residential PV array, which factor is most important when evaluating roof pitch for energy production?

Accepted Answer

The angle's effect on tilt, which influences annual irradiance capture

Answer

Roof pitch determines array tilt angle, which directly affects how much solar irradiance the modules intercept throughout the year.

Question 3

A combiner box in a large PV array is used to:

Accepted Answer

Combine multiple source circuits into a single output circuit with overcurrent protection per string

Answer

A combiner box parallels multiple strings, providing fuse or breaker protection for each source circuit before connecting to the inverter.

Question 4

According to NEC 690.12, rapid shutdown of a PV system is required primarily to:

Accepted Answer

Reduce voltage in roof-mounted conductors to protect first responders

Answer

Rapid shutdown requirements protect firefighters and other first responders from energized conductors on and near the roof.

Question 5

The term 'specific yield' in PV system performance refers to:

Accepted Answer

Annual energy production per kilowatt of installed DC capacity (kWh/kWp)

Answer

Specific yield, expressed in kWh/kWp, normalizes annual energy output to system size and enables comparison across different system sizes and locations.

(NABCEP) Certified North American Board of Certified Energy Practitioners Specialist Practice Test

(NABCEP) Certified North American Board of Certified Energy Practitioners Specialist Practice Test

NABCEP PV System Design Principles 3