Surface Solar Radiation from Geostationary Satellites for Renewable Energy

Solar radiation available at the surface has been routinely derived in real time from Geostationary Operational Environmental Satellite (GOES) data at the National Oceanic and Atmospheric Administration (NOAA), National Environmental Satellite, Data and Information Service (NESDIS) in a processing system known as the GOES Surface and Insolation Product (GSIP) system. The GSIP system has recently been upgraded to provide retrievals experimentally at a spatial resolution of ~ 4 km. The planned rapid observations (5-15 minutes) from the Advanced Baseline Imager (ABI) on the upcoming GOES-R satellite will enhance the capabilities realized in the current GCIP for solar resources where frequent observations of solar radiation reaching the surface are essential for planning and load management. The algorithms used in GSIP and with ABI are based on radiative transfer, represented in look-up-tables, and internally retrieve clear-sky and cloudy-sky transmittances (GSIP), or use atmospheric and surface parameters derived independently from multispectral radiances (ABI) for calculating these transmittances. Tests, performed using the Moderate Resolution Imaging Spectroradiometer (MODIS) data, have shown that the ABI algorithm is superior to the GSIP algorithm. The algorithms are designed to provide basic radiation budget products (e.g., total solar irradiance at the surface), as well as products specifically needed in the solar energy sector (average, midday and clear-sky insolation, clear-sky days, diffuse and direct normal radiation, etc.). The accuracy of surface solar radiation retrievals are assessed using long-term GOES and MODIS satellite data and surface measurements at the Surface Radiation (SURFRAD) network.