Hybrid CSP-PV plants with integrated thermal storage.

With the cost of solar electricity generated by photovoltaic (PV) systems dropping, the integration of PV into concentrating solar power (CSP) plants is under active consideration. PV systems are more economical in providing electricity directly to the grid during sunshine hours, whereas the main advantage of CSP plants is the availability of economical large thermal storage (TES), especially when molten salt is used as heat transfer and storage fluid. Several options to combine the strengths of the two technologies are evaluated in this paper, including: a small PV plant designed to supply the CSP plant's own consumption; hybrid CSP-PV plants where the CSP plant is mainly used to charge the storage while the PV system delivers electricity to the grid during the daytime and optionally charges the storage by means of electrical heaters ("eTES"); and finally a PV only system that provides electricity during daytime and additionally charges the thermal storage by electrical heaters. The different hybrid operation strategies are evaluated for a typical plant located in Southern Spain with mediocre direct solar irradiation. A sensitivity study on the impact of a high DNI CSP location like South Africa and an advantageous feed-in tariff at night on the plant's economics is presented. [ABSTRACT FROM AUTHOR]