Solar Irradiance Calculator
Calculate solar irradiance and energy potential based on your location and panel orientation.
Irradiance Formulas
GHI = 1.353 kW/m2 x sin(altitude) x atmosphere
POA = GHI x tilt_factor x azimuth_factor
PSH = POA x day_hours / 1000
GHI = Global Horizontal Irradiance, POA = Plane of Array irradiance, PSH = Peak Sun Hours
Typical Values by Region
| Region | PSH (Summer) | PSH (Winter) | Annual Avg |
|---|---|---|---|
| Southwest US | 7-8 | 4-5 | 5.5-6.5 |
| Southeast US | 5-6 | 3-4 | 4.5-5.0 |
| Northeast US | 5-6 | 2-3 | 3.5-4.5 |
| Pacific NW | 5-6 | 1-2 | 3.0-4.0 |