Performance of new designed meta-material absorbers/emitters reshaping solar spectrum to double-narrowband emissive spectrum for STPV power generation

Solar thermophotovoltaic system can reshape the solar spectrum and improve the conversion efficiency of photovoltaic. In this study, the characteristics of ideal selective absorber for AM0 and AM1.5 solar spectra are compared, and the principles are summarized to design a metamaterial absorber for different spectra. The absorption efficiency can reach more than 80 % at the high temperature of 1700 K. This study innovatively proposes a STPV system that matching a double-narrowband (DNB) emitter with Si/InGaAsSb tandem cells. The theoretical efficiency of STPV with a DNB emitter is about 4 % higher than that with a wide-band (WB) emitter by analyzing thermodynamic model. Accordingly, a metamaterial DNB emitter is designed. The results show that the DNB metamaterial selective emitter designed in this study can achieve a TPV efficiency of near 50 %. The concentrating ratio and temperature have an inverse effect on the absorption efficiency and TPV efficiency. The optimized STPV system efficiencies for AM0 and AM1.5 are 37.29 % and 37.20 % under typical condition, respectively, which are a great improvement compared to the solar PV cell. The proposed metamaterial absorber and DNB emitter have great application potential in power generation for both space and ground conditions.