Approximations to the CPC—a comment on recent papers by Canning and by Shapiro

Abstract

Innovative concentrating PVT solar collector concepts based on a CPC geometry concept were developed to outperform the asymmetric Solarus CPVT collector and therefore decrease the energy/performance gap between CPVT and PV/ST solar collectors.The updated reflector geometry proved to be the most suitable reflector geometry for CPVTs, where the electrical peak efficiency per gross area reached 10.6%, which is +16.5%rel higher than the electrical peak efficiency of the Solarus CPVT. Optical efficiencies of η0 = 62.3% and η0 = 61.8% for CPC 1 and CPC 2 have been achieved, respectively.A PV module (0.5 m2) combined with an ST solar collector (0.5 m2) system to be able to deliver the same overall energy yield as the newly developed CPVT collector (1 m2) requires on average +0.02 m2 (at 45 °C), −0.06 m2 (at 55 °C) and −0.15 m2 (at 65 °C) of installed area, for a wide range of latitudes.A CPC-PVT system to increase its competitiveness requires a material cost reduction and at the same time an increased overall efficiency. Nevertheless, the energy/performance gap between a system composed of PV + ST technologies and a CPC-PVT decreased significantly.