Solar Irradiance Calculator
Estimate daily solar energy received on a surface based on peak sun hours and panel orientation derating.
Daily Irradiance
4.50 kWh/m²/day
Daily Irradiance vs Peak Sun Hours per Day
Formule
## 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.
Exemple Résolu
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
Questions Fréquentes
What are peak sun hours?
Peak sun hours represent the equivalent hours per day of sunlight at 1,000 W/m² intensity. Five peak sun hours means the total daily energy equals five hours of full noon sun.
How does panel angle affect irradiance?
Tilting panels to match your latitude maximizes annual energy capture. The orientation factor accounts for sub-optimal tilt or azimuth angles.
Where can I find peak sun hours for my area?
The NREL PVWatts tool and Global Solar Atlas provide location-specific solar resource data including peak sun hours.