10% efficiency solar thermophotovoltaic systems using spectrally controlled monolithic planar absorber/emitters

Abstract

In solar thermophotovoltaic (STPV) generation systems, the thermal radiation from emitters heated by the high temperature solar absorbers is converted into electricity at a photovoltaic (PV) cell. STPV systems have some advantages over PV generation systems. For instance, it is possible to control the thermal radiation spectrum of the emitter. Generally, the PV cell has an inherent sensitive region where an incident photon excites the electron. Enhancing the thermal radiation in this sensitive region of the PV cell, therefore, increases the generation efficiency. Theoretically, the efficiency of STPV systems can reach up to 85% when Carnot efficiency is considered and up to 45% when a monochromatic radiation releasing emitter is used. However, the experimental STPV system is less efficient than theoretical one as a consequence of the large amount of heat loss from the high-temperature absorber/emitter system. The purpose of this study is to achieve a high-efficiency STPV generation system using a monolithic planar spectrally selective absorber/emitter. The temperature superiority of the monolithic planar absorber/emitter is estimated by using spectral and thermal properties of STPV system components. Using the enitre configuration of the STPV system, a system efficiency of over 10% is estimated in this study.

Concentrating Solar Power

“…80 Shimizu, et al also used a selective absorber/emitter to estimate up to 8% conversion efficiency, although this was not directly demonstrated. 338 STPV efficiency is predicted to reach 20% for systems scaled up to larger absorber/emitter areas (which reduces the effect of edge losses) and which use higher quality PV cells and sub-bandgap filtering. 192 A demonstration of an STPV device with efficiencies comparable to existing CSP plants would suggest the potential for economical STPV systems and smaller scale CSP technology.…”

“…Rinnerbauer et al used a monolithic two-dimensional photonic crystal absorber and emitter on a single chip to demonstrate 3.5% STPV conversion efficiency . Shimizu et al also used a selective absorber/emitter to estimate up to 8% conversion efficiency, although this was not directly demonstrated . STPV efficiency is predicted to reach 20% for systems scaled up to larger absorber/emitter areas (which reduces the effect of edge losses) and that use higher quality PV cells and sub-bandgap filtering .…”

Concentrating Solar Power

“…80 Shimizu, et al also used a selective absorber/emitter to estimate up to 8% conversion efficiency, although this was not directly demonstrated. 338 STPV efficiency is predicted to reach 20% for systems scaled up to larger absorber/emitter areas (which reduces the effect of edge losses)…”