NABCEP PV System Design Principles 2

Question 1

When sizing a PV array for a battery-based off-grid system, which factor most directly determines the minimum array size?

Accepted Answer

Peak sun hours at the site

Answer

Peak sun hours represent the equivalent hours of full irradiance and directly determine how much energy the array can produce per day.

Question 2

A PV system is designed with modules having a temperature coefficient of Pmax of -0.35%/°C. If STC is 25°C and the cell temperature reaches 65°C, by what percentage does output power decrease?

Accepted Answer

14%

Answer

The temperature rise is 65 - 25 = 40°C, and 40 × 0.35% = 14% power reduction.

Question 3

In a grid-tied PV system, the primary function of the inverter is to:

Accepted Answer

Convert DC power from the array to AC power for the grid

Answer

The inverter converts the DC output of the PV array into AC power compatible with the utility grid.

Question 4

Which NEC article primarily governs the installation of photovoltaic systems?

Accepted Answer

Article 690

Answer

NEC Article 690 specifically covers solar photovoltaic systems and their installation requirements.

Question 5

The 'fill factor' (FF) of a PV module is best described as:

Accepted Answer

The ratio of maximum power to the product of Voc and Isc

Answer

Fill factor = Pmax / (Voc × Isc) and measures how close the I-V curve approaches an ideal rectangle.

(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 2