Retrofitting operating CSP plants with PV to power auxiliary loads - Technical consideration and case study

Abstract

In the context of Concentrating Solar Power (CSP) plants, Photovoltaic (PV) augmentation is the process whereby the online parasitic loads (also known as auxiliary loads) of a CSP plant are supplemented by a PV facility located on site. Typically, the cost of energy generated by a PV plant is lower than that generated by a CSP plant and thus, PV augmentation can improve the financial return of CSP projects. While previous work has explored the topic primarily from the point of view of using CSP-PV hybridization on new build CSP or to provide baseload power, this paper focuses specifically on retrofitting existing CSP plants with a PV facility to service only the auxiliary loads. It discusses the technical and design considerations for PV integration in operational CSP plants, as well as the typical regulatory and permitting constraints that are expected to be encountered in offtake agreements. The paper also presents an analytical modelling tool developed by the authors and presents a case study to demonstrate the various design and optimisation strategies, the benefits, and the economic gains which are possible in CSP-PV augmentation.