Optimization of Thermophotovoltaic Power System With a Spectrally Controlled Multi-Concentric Emitter

Abstract

Abstract Thermophotovoltaic energy conversion is a solid-state thermal-to-electric energy conversion technique which uses only infrared light i.e., heat. Its maximum achieved efficiency by proper bandgap energy selection and utilizing spectral control strategies is merely 30% which is currently still low to be used as a standalone device for energy harvesting. Recently, researchers used molten metal storage and concentrated solar power (CSP) as an input to derive these thermophotovoltaic blocks. Such blocks usually consist of an emitter and a photovoltaic power converter which boosted the system efficiency by adding a silver-based reflector to bounce unused photons back to the emitter. In this work, we have demonstrated another means of photon recycling on the conversion efficiency by passing the radiations through spectral filters before incident on these cells. The spectral filters were selected by aiming at gaining maximum conversion efficiency and a cylindrical power block was used in order to reduce the conversion losses due to edge effects. The modified model in terms of geometrical shape and spectrally controlled filters was able to achieve a conversion efficiency up to 50% even without using the back surface reflectors (BSRs). This work provides the framework for a cheap and efficient alternative to the combined-cycle electric turbines currently used to convert heat into energy inside utility-scale concentrated solar power facilities. This work enables widespread use wherever solar energy is available in abundance.