Optimal design principle of a cascading solar photovoltaic system with concentrating spectrum splitting and reshaping

Abstract

In this paper, an optimal design method and principle of a cascading solar photovoltaic (PV) system with concentrating spectrum splitting and reshaping is proposed. The cascading solar PV system uses a second thermophotovoltaic (TPV) subsystem to reshape the spectrum which cannot be efficiently used by first PV subsystem for reuse to realize cascading solar energy utilization of full spectrum. The method optimizes the solar energy distribution and TPV key component in the PV-TPV system for the first time. Through the optimal design method, the system parameters such as the optimal cutoff wavelength of the spectral splitter and the optimal absorptivity of the TPV absorber are obtained. At the same time, the specific effects of cutoff wavelength of the spectral splitter, TPV intermediate area ratio, system concentration ratio, TPV absorber and PV cell area ratio, cooling system heat transfer coefficient, and different TPV cells on the hybrid system are analyzed. At 1000 concentration ratios, the hybrid system achieves an electrical efficiency of 35.69%, which is 9.55% points higher than single PV system. The system also has efficiency and economic advantages over other concentrating hybrid systems. This paper provides guidance for the subsequent design and construction of the PV-TPV hybrid system.