Photovoltaic Power Production Estimation Based on Numerical Weather Predictions

A photovoltaic (PV) power generation system relying on meteorological forecast provided by the European Centre for Medium-Range Weather Forecast (ECMWF) (ERA5 database) is proposed. Three years of data collected from photovoltaic panels deployed in Milan, Italy, have been analyzed, both in clear-sky and cloudy conditions. The Ineichen-Perez model has been used as a reference for clear-sky conditions. The power measurements were compared with the power calculated using ECMWF, based on solar theory and technical characteristics of the PV plant in place. cumulative complementary distribution function (CCDF) and errors, have been calculated to determine the accuracy of the model. Results indicate a good agreement in terms of generated power statistics, showing that ERA5 data can be reliably used to design solar plants as well as to forecast their performance and energy production.