Verification of direct normal irradiance foreasts for the concentrating solar thermal power plant Andasol-3 location

The successful integration of solar electricity from concentrating solar power plants into the existing electricity supply requires an electricity production forecast for 48 hours, while any improved surface irradiance forecast over the next upcoming hours is relevant for an optimized operation of the power plant. In order to quantify the quality of today’s state of the art, meteorological ground-based measurements are obtained from the Andasol location (near Guadix, Spain). A verification is performed for commercially available DNI forecasts based on Model Output Statistics (MOS) and for a data set based on the ECMWF IFS numerical weather prediction model. Generally, the ECMWF day ahead forecast performs better than the MOS-based approaches at the Andasol location for the test years of 2007 to 2009. Additionally, a nowcasting scheme based on Meteosat Second Generation cloud imagery and cloud movement tracking is currently under development. Preliminary results show a positive impact of up to 8 hours depending of the time of the day and a RMSD reduction of up to 10%. This illustrates the potential of the further development of a satellite-based nowcasting scheme