Comparison of satellite imagery based data, reanalysis data and statistical methods for mapping global solar radiation in the Lerma Valley (Salta, Argentina)

Global solar radiation is the most important factor to determine the energy generation potential of photovoltaic (PV) plants. In Argentina only a small number of ground measured data of global solar radiation exists. Researchers and PV developers have to use statistical methods or satellite imagery to handle this lack of information and provide an estimation of global solar radiation for a particular location. In this paper global solar radiation data sources for the Lerma valley are explored in order to assess which data set is best suitable for future studies of photovoltaic energy generation potential at the best possible spatial and temporal resolution. We evaluate global solar radiation from the reanalysis data set provided by the European Centre for Medium-Range Weather Forecasts (ECMWF) and the Meteosat second generation derived data set provided by Land Surface Analysis Satellite Applications Facility (LSA-SAF). These are compared with each other, with data generated using statistical methods and with data from a pyranometer. The results show that the data from LSA-SAF fit best to the ground measurements. This together with a high spatial and temporal resolution makes the LSA-SAF data a satisfactory alternative to compensate the lack of global solar radiation data available for the study area.