NABCEP - Certified North American Board of Certified Energy Practitioners Specialist PV System Design Principles Questions and Answers

Question 1

A PV system designer is selecting a string inverter for a 12 kW STC DC array located in a moderate climate.
To optimize annual energy harvest by balancing performance gains against minimal power clipping, which of the following DC-to-AC load ratios is most appropriate for this design?

Accepted Answer

1.25

Answer

0.95

Answer

1.00

Answer

1.75

Question 2

According to NEC® 690.7, what is the most critical factor to use when calculating the maximum system voltage of a PV string to ensure it does not exceed equipment voltage ratings?

Accepted Answer

The module's open-circuit voltage (Voc) temperature coefficient

Answer

Peak summer cell temperature

Answer

The module's short-circuit current (Isc) at STC

Answer

Average annual ambient temperature

Question 3

Which of the following design strategies is most effective at mitigating energy production losses caused by partial shading of a single module within a larger series string?

Accepted Answer

Employing module-level power electronics (MLPE)

Answer

Using a larger gauge conductor for the string wiring

Answer

Installing the array at a steeper tilt angle

Answer

Increasing the DC-to-AC load ratio

Question 4

A designer is sizing the conductors for a PV source circuit. The module Isc is 10A. Per NEC® 690.8, the conductors must be sized to carry at least what minimum ampacity before any adjustments for conditions of use?

Accepted Answer

15.6 A

Answer

10.0 A

Answer

12.5 A

Answer

15.0 A

Question 5

For a fixed-tilt residential PV system located in the Northern Hemisphere, which orientation is generally recommended to maximize total annual energy production?

Accepted Answer

True south at a tilt angle equal to the site's latitude

Answer

Magnetic west at a 45-degree tilt angle

Answer

True north at a tilt angle 15 degrees less than latitude

Answer

Due east at a low tilt angle (10 degrees)

Question 6

When designing the mechanical mounting and racking plan for a rooftop PV system, which of the following environmental forces is a primary consideration for ensuring the structural integrity of the array and roof?

Accepted Answer

Wind uplift load

Answer

Seismic load

Answer

Dead load

Answer

Snow load

A PV system designer is selecting a string inverter for a 12 kW STC DC array located in a moderate climate.To optimize annual energy harvest by balancing performance gains against minimal power clipping, which of the following DC-to-AC load ratios is most appropriate for this design?

A PV system designer is selecting a string inverter for a 12 kW STC DC array located in a moderate climate.
To optimize annual energy harvest by balancing performance gains against minimal power clipping, which of the following DC-to-AC load ratios is most appropriate for this design?