Survey and Quality Assessment of Solar Radiation Data Sources in the United States

A survey of measured ground station solar radiation data sources in the U.S. was conducted between 6/95 and 6/96, under contract to the National Renewable Energy Laboratory (NREL). This work was done to establish a more spatially comprehensive ground stations solar radiation data set to validate satellite mapping models and to support other work ar NREL. 171 data sources were identified,representing 1,420 sites where solar radiation measurements have been taken at hourly or shorter time intervals for a period of at least one year. Fig. 1 shows site locations in the 48 contiguous states, and Figs. 2 and 3 show sites in Hawaii and Alaska. A preliminary data quality assessment by site was drawn from phone interviews. A system was devised to rate the value of the respective datasets to NREL for R&D purposes. The highest value data sets were identified, and obtained where possible. A detailed data quality assessment was performed on 52 of the highest value data sets that could be obtained, and the results, along with the data sets in a standard format were delivered to NREL. A Data Source Information Database was also developed, detailing site and networkcharacteristics, as well as contact and availability information.