Concepts for combining concentrating solar mirrors with PV modules

Abstract

Concentrating solar thermal (CST) technologies produce renewable, sustainable heat at elevated temperature. In this work four concepts are compared to integrate photovoltaic cells into CST heliostats and at tower receivers to increase efficiency and decrease cost of the systems. Based on previous research, parameters are derived which describe energy production and investment cost of the concepts. It is found that the integrated concepts can increase the total annual energy production of a concentrating solar power plant by 23% to 40%, justifying investment cost increase compared to the conventional configurations. According to this the concepts utilizing a spectrally selective mirror on top of PV cells to replace the concentrating mirrors are expected to be economically feasible. The concentrating PV concept produces electricity at lower cost than separate stand-alone PV if the spillage radiation flux around the receiver of CST tower plants is higher than around 350 kW/m2.