Sub-Hour Evaluation of Global Horizontal Irradiance From the Physical Solar Model (Psm) Including Latitudes Below 20°S
Abstract
Since 2018 the Physical Solar Model (PSM) used for generating solar irradiance estimates in the National Solar Radiation Database (NSRDB) provides estimates for the Americas with a maximum time resolution of 10 minutes and approximate spatial resolution of 4 x 4 km (latitude, longitude). The performance of this model at hour and sub-hour time intervals has not been evaluated beyond 20°S. This work provides performance indicators at the 10 and 60 min timescales for the Global Horizontal Irradiance (GHI) component of the model, using 4 years (2020-2023) of controlled quality 1 min data from four ground stations in Uruguay, located in latitudes between 30 and 35°S. Three sites of similar latitudes in the northern hemisphere from the SURFRAD network (United States) have also been included for comparative purposes. The results show small positive mean biases below 4% (for both time scales) at all but one site, and relative RMSD in the ranges 15 28% and 10-16% at the 10 minute and 60 minute timescales, respectively. These preliminary results confirm PSM as a useful tool for solar irradiance estimations at southern latitudes between 30 and 35°S.
Keywords
Solar radiation, PSM, National Solar Radiation Database, Global Horizontal Irradiance, South America