Solar Irradiance Calculator
Estimate daily solar energy received on a surface based on peak sun hours and panel orientation derating.
hours
m²
Daily Irradiance
4.50 kWh/m²/day
Daily Energy on Panel90.0 kWh/day
Annual Energy on Panel32,850 kWh/yr
Daily Irradiance vs Peak Sun Hours per Day
Solar Irradiance and Energy Collection
Solar irradiance is the power of sunlight per unit area. Peak sun hours convert variable sunlight into an equivalent number of hours at 1,000 W/m².
Formula
Daily Energy (kWh/m²) = Peak Sun Hours x Orientation Factor
Total Daily Energy = Daily Energy x Panel Area
Peak sun hours vary by location: 3-4 in northern climates, 5-6 in temperate zones, and 6-8 in sunny regions.
Example Calculation
A 20 m² array in a location with 5 peak sun hours and 90% orientation factor.
- 01Effective irradiance = 5 x 0.9 = 4.5 kWh/m²/day
- 02Daily energy = 4.5 x 20 = 90 kWh/day
- 03Annual energy = 90 x 365 = 32,850 kWh/year