SHINING ON

National Solar Radiation Data Base

Using data collected from 1961 through 1990, the National Solar Radiation Data Base will replace the SOLMET/ERSATZ dats base derived from data collected from 1952 through 1975. The new data base will more accurately portray the solar resource for the following reasons:

The 30-year period of data collection is long enough to establish averages and extremes of solar radiation paramaters, and it coincides with the same 30-year period used for the National Oceanic and Atmospheric Administration's latest update of climate statistics.
More measured data were available during 1961 through 1990. For the SOLMET/ERSATZ data base, there was only one measured parameter; global horizontal solar radiation at 26 sites. The new data base has measured data for up to 55 of the 250 sites. For a majority of these 55 sites, two parameters were measured: global horizontal solar radiation and direct beam solar radiation. Diffuse solar radiation was also measured for several years at nine sites.
Better models estimate solar radiation at sites and times where no measurements are available. A meteorological statistical model provides better estimates of solar radiation for sites and times where no measurements are available.
The certainty of the measured data is better. A radiometer calibration facility, set up by the National Oceanic and Atmospheric Administration in Boulder, Colorado, performed routine calibrations to ensure the accuracy of instruments used to measure solar radiation.
Quality assessment procedures flag solar radiation data to show the source of the data (measured or modeled) and the uncertainty. Unlike the SOLMET/ERSATZ data, this permits the user to assess the uncertainty of the data.

Return to RReDC Homepage ( http://www.nrel.gov/rredc )