Modeling of Spectral Irradiance in the POA Using GOES Satellite Data

The solar energy industry often uses individual steps to empirically compute plane-of-array (POA) irradiance from horizontal irradiance and decompose it to narrow-wavelength bands. Conventional radiative transfer models designed for meteorological applications requires significant computing efforts in practice; however, they provide a physics-based solution of radiance and therefore are capable of computing spectral POA irradiances in a single step. In this study, we integrate the advantages of the current models and develop an innovative radiative transfer model, the Fast All-sky Radiation Model for Solar applications with Narrowband Irradiances on Tilted surfaces (FARMS-NIT), to efficiently compute irradiances on inclined photovoltaics (PV) panels for 2002 narrow-wavelength bands from 0.28 to 4.0 µm. The validation analysis confirms that FARMS-NIT has improved accuracy compared to TMYSPEC as evaluated by both surface observations and a state-of-the-art radiative transfer model. FARMS-NIT substantially improves computational efficiency compared to other radiative transfer models. It will implement cloud property retrievals from GOES satellite data to compute spectral irradiances on photovoltaic (PV) panels which will be disseminated as a component of National Renewable Energy Laboratory’s (NREL’s) National Solar Radiation Data Base (NSRDB).