A model of integration between PV and thermal CSP technologies

Abstract

A model of integration between thermal CSP and PV technologies is discussed, showing the complementarity of the two technologies for electricity production. In the model, a CSP system with thermal storage is coupled with a PV system without storage: the PV field is expected to supply most of the electricity needed during the day and the CSP is expected to supply energy especially in the night, exploiting the storage. Excess of electric production due to PV is degraded to thermal energy and recovered in the heat storage system to integrate the thermal cycle, in order to keep the system as stand-alone as possible and to stabilize the connection with the power grid. Such a model is a non-compact hybrid PV-CSP system, i.e. the two solar fields operate independently (sharing the storage). Detailed annual simulations with realistic irradiance sequences and load profiles are presented and discussed. Results show that the solar energy can cover the 67% of the electricity needed by a Mediterranean community – despite the strong seasonal variation of the solar irradiation – and more than 90% of a constant electric load (24 hours / 7 days, e.g. an industrial district) in locations with low seasonal change of overall solar irradiation, such as a semi-arid sub-Saharan site.