Parametrical analysis of a novel solar cascade photovoltaic system via full-spectrum splitting and residual-spectrum reshaping

Abstract

In this study, a novel cascade photovoltaic power generation system via full-spectrum splitting and residual-spectrum reshaping is proposed to realize the cascade conversion of solar energy. A cavity-structured absorber and outer-wall emitter combined device is designed for reshaping the residual infrared spectrum, and the corresponding physical model is also established. The parametric analysis of the whole system is conducted to investigate the effect of cavity structure, second-stage cell, spectrum-split frequency, selective emitter and concentration ratio on the system performance. The results indicate that the system efficiency can reach 34.32%, which is higher than that of solar photovoltaic (27.6%) by 6.72 percentage points. It is founded that the solar thermophotovoltaic conversion system equipped with the cavity-structured absorber, whose absorption efficiency can reach more than 99.06%, can efficiently absorb and utilize the infrared residual spectrum. The cavity structure can avoid the manufacture of complex micro/nano structured materials and the high design cost of selective absorber. When Si is selected as second-stage photovoltaic cell and the selective emitter is used, the system efficiency is higher than that using GaSb cell by about 2–3 percent points. Besides, the lower cost of Si cell also provides certain application advantages. The result of this study paves a theoretical guiding for the development and application of solar photovoltaic technology.