Impact of DNI Nowcasting on Annual Revenues of CSP plants for a time of delivery based feed in tariff

Abstract

The impact of a combined nowcast for direct normal irradiation on revenues of two different concentrating solar power plant technologies under a time-of delivery-tariff is investigated. The nowcasts merge several satellite and NWP based nowcasts together with a smart persistence approach in order to generate a best-of nowcast for all now- and forecast time horizons up to 9 hours and in a 15 min temporal resolution. The applied tariff scheme is similar to that used in South Africa for some of the CSP plants erected in that country with considerably increased remuneration during the evening hours with maximum energy demand. The study investigates the impact both with respect to the annual energy yield and the economic annual revenues of CSP plants. The results for the combined nowcast are compared with results using ECMWF IFS based DNI forecasts which are commercially available for plant operators as well as with a persistence approach and the ideal forecast derived from ground-based observations.