Design and Operation of Hybrid CSP-PV-Wind Plants Operating on the Italian Day-Ahead Electricity Market and on the Ancillary Services Market

Concentrating Solar Power equipped with Thermal Energy Storage (TES) allows for dispatchable power production, but the worldwide installed power is still limited due to its higher investment costs with respect to other renewable technologies. A promising option to reduce costs, while keeping a high dispatchability level, is the hybridization of CSP with Photovoltaic (PV) and wind turbine (WT) plants. Hybrid CSP-PV-Wind plants have already shown their capability to achieve higher dispatchability level and lower costs with respect to stand-alone CSP, PV and wind plants. This work investigates the techno-economic optimization of hybrid CSP-PV-Wind plants capable of operating on both the Day Ahead Market (DAM) and the Ancillary Services Market (ASM), assuming different market scenarios. The design and operation of the hybrid plant are co-optimized using the optimization framework developed by Politecnico di Milano and considering the simultaneous participation of such plant to the DAM and ASM Italian markets. Results showed that while a price multiplier of 4 should be applied to the current spot market prices to make the hybrid plant economically viable in the DAM market, a price multiplier of 2 is sufficient for a positive NPV when also the revenues from the ASM market are considered. Moreover, the CSP turn out to be an essential flexibility provider: conversely to the solution combining PV and WT with a battery storage, CSP-based configurations avoid the need for a large battery for the reserve provision, with a significant economic benefit on the plant NPV.