Combining Numerical Weather Predictions and Satellite Data for PV Energy Nowcasting

The increasing presence of photovoltaic (PV) generation in the energy mix demands improved forecasting tools which can be updated in an almost continuous basis. Satellite-based information lends itself naturally to this purpose and here it is used to nowcast hourly PV energy production for horizons up to six hours over Peninsular Spain and two islands, Majorca in the Mediterranean Sea and Tenerife in the Atlantic Ocean. This paper compares a single model-based on same-day numerical weather prediction (NWP) with hourly refreshed models which either only use satellite-based measurements or which combine both NWP same-day forecasts and satellite data. As shown in the experiments, the satellite-NWP combination gives very good nowcasting results, clearly superior to those achievable separately by either approach.