EnviroAtlas - Average Direct Normal Solar resources kWh/m2/Day by 12-Digit HUC for the Conterminous United States
The annual average direct normal solar resources by 12-Digit Hydrologic Unit (HUC) was estimated from maps produced by the National Renewable Energy Laboratory for the U.S. Department of Energy (February 2009). The original data was from 10km, satellite modeled dataset (SUNY/NREL, 2007) representing data from …