SOLAR POTENTIAL
Source: National Renewable Energy Laboratory (NREL)

The map is color-coded based on the following scale. The figures below correspond with the solar potential map scale, and they are measured in watt hours per square meter, per day (Wh/m squared/day).

• 0 to 4500 (Lowest Potential)
• 4500 - 5000
• 5000 - 5500
• 5500 - 6000
• 6000 - 6500
• 6500 and over (Highest Potential)

Monthly and annual average solar resource potential for 48 contiguous United States. The insolation values represent the average solar energy available to a flat plate collector, such as a photovoltaic panel, oriented due south at an angle from horizontal equal to the latitude of the collector location. This data provides monthly average and annual average daily total solar resource averaged over surface cells of 0.1 degrees in both latitude and longitude, or about 10 km in size. This data was developed using the State University of New York/Albany satellite radiation model. This model was developed by Dr. Richard Perez and collaborators at the National Renewable Energy Laboratory and other universities for the U.S. Department of Energy. Specific information about this model can be found in Perez, et al. (2002).