Certified Energy Auditor Certification Renewable Energy Systems 2

Question 1

What does 'peak sun hours' mean as used in PV system sizing?

Accepted Answer

The equivalent number of hours per day with solar irradiance at exactly 1000 W/m²

Answer

Peak sun hours represent the equivalent number of hours per day that a location receives solar irradiance of 1000 W/m² (STC conditions), and are used to estimate daily PV energy production.

Question 2

For a fixed-tilt PV installation in the continental US, what is the general rule for maximizing annual energy production?

Accepted Answer

Set tilt angle equal to local latitude, oriented toward true south

Answer

Setting the tilt angle equal to the local latitude and orienting panels toward true south maximizes annual solar energy capture for fixed installations in the Northern Hemisphere.

Question 3

What is the typical annual degradation rate of crystalline silicon PV modules?

Accepted Answer

0.5% per year

Answer

High-quality crystalline silicon PV modules typically degrade at approximately 0.5% per year, retaining about 80–87% of rated output at the end of a 25–40 year lifetime.

Question 4

Which inverter technology is best suited for maximizing energy harvest when individual PV panels may experience partial shading?

Accepted Answer

Microinverter or DC power optimizer

Answer

Microinverters and DC optimizers perform maximum power point tracking (MPPT) at the individual panel level, preventing one shaded panel from degrading the output of the entire string.

Question 5

A rooftop PV system is rated at 50 kW STC. Using a derate factor of 0.80 and 5 peak sun hours per day, what is the estimated daily energy production?

Accepted Answer

200 kWh/day

Answer

Daily production = 50 kW × 0.80 derate factor × 5 peak sun hours = 200 kWh/day.

Certified Energy Auditor Certification Practice Test

Certified Energy Auditor Certification Practice Test

Certified Energy Auditor Certification Renewable Energy Systems 2