Parametric optimization of a novel solar concentrating photovoltaic-near field thermophotovoltaic hybrid system based on cascade utilization of full-spectrum solar energy

Abstract

Based on cascade utilization of full-spectrum solar energy, a novel solar concentrating photovoltaic and near-field thermophotovoltaic hybrid system (CPV-NFTPVS) is proposed to achieve efficient solar power generation. The full-spectrum solar energy is split into two parts by spectrum splitter: The high-frequency part is provided to concentrating photovoltaic module while the rest to near-field thermophotovoltaic module. The effect of operating parameters such as concentration ratio, split wavelength, applied voltage, and vacuum gap on the energy conversion performance of the hybrid system is investigated. Starting with a concentration ratio of only 210, the efficiency of the hybrid system exceeds the maximum efficiency of near-field solar thermophotovoltaic system (NF-STPVS) with a concentration ratio of 2000. Considering the technical difficulties of the ultrahigh concentration ratio and ultrahigh cooling rate, a concentration ratio of 1000 is a practical choice for the hybrid system and its efficiency reaches 56.20%, which is about 1.12 times higher than the maximum efficiency of NF-STPVS. The law of the optimal value of the operating parameters is further explored and it's found that the optimal gap distance is always 10 nm and the optimal split wavelength needs to be adjusted according to the concentration ratio. The significant value of CPV-NFTPVS based on cascade utilization in solar power generation is indicated and practical application of the near-field thermophotovoltaic is guided.