Assessment and comparison of concentrator cell carrier efficiencies under very high fluxes

Abstract

The present work aimed at assessing and comparing the thermal performances of two different types of carrier exposed to natural sunlight beams concentrated up to 1,500 - 5,000 suns. Metallic and hybrid metal-ceramic carriers of various dimensions, or bonded to cells of different sizes, were considered. Temperature profiles inside the carriers exposed to concentrated beams were measured using temperature sensors placed at two different locations. 3D heat transfer simulations of a carrier bonded either to the real Ge-based solar cell or to the dummy cell instrumented for our temperature measurements showed that the measured temperatures differ by less than a couple of degrees from the real solar cell surface temperatures within a large range of concentration. Experimental results and thermal simulations confirmed the need to select a high-conductivity carrier combined with a very efficient active device for cooling solar cells under very high concentration. In addition, the key role played by thermal constriction in the heat transfer process was highlighted, demonstrating the importance of carefully optimizing the carrier design.