State/Territoy Data Tables Tables include the "Averages of solar radiation for each of the 360 months during the period of 1961-1990" and "30-year (1961-1990) average of monthly solar radiation".
PV Collector Performance Maps Interactive maps on NREL's Internet Map Server; to view the "Solar Radiation Data Manual for Flat-Plate and Concentrating Colectors" tables, uncheck "Launch PVWATTS v.2", check collector-type data table to view. Zoom in (maginfying glass with "+"), then select Hot link tool (lightning bolt); click on area of interest.
Data Files in ASCII Text Format Averages of solar radiation for each of 360 Months, 1961-1990 for 239 U.S. sites; and thirty-year averages of monthly solar radiation, 1961-1990 for 239 U.S. sites
