Peak sun hours: converter and quick sizing

Step 1 turns an irradiation figure into peak sun hours (PSH). Step 2 sizes an array with the shortcut kWh/day = kWp x PSH x system factor. It is a rough check, not a simulation. The default numbers are invented.

1. Convert irradiation to peak sun hours

Value (4,29 or 1,566.2 both work)

Unit

Per

Days in the month (used only for "month")

Peak sun hours per day: - (kWh/m² a day divided by 1 kW/m²)

2. Quick sizing

Daily energy target, kWh/day

PSH on the array plane (invented)

System factor (0.78 invented), or 78%

Module rating, W

Array needed: - kWp

Modules, rounded up: - (- kWp)

Rounded array makes: - kWh/day at this PSH

Per kWp: - kWh/kWp/day

Use a monthly PSH to size for that month. A yearly PSH gives a yearly average only.

Factors: 1 kWh = 3.6 MJ. Daily values above 13.5 kWh/m² are rejected as above what a horizontal surface can receive. The system factor must be 0.2 to 1 (or 20% to 100%).