Efficiency boost and financial analysis of the thermophotovoltaic power system by photonic potential

Abstract

A hybrid thermophotovoltaic system for thermal-to-electrical energy conversion is a solid-state technique that exclusively utilizes infrared light. However, it faces an upper limit on its conversion efficiency. In this study, its performance is enhanced by integrating concentrated solar energy and a thermal battery. A surface-to-surface radiative analysis in COMSOL is conducted to determine the thermal-to-electrical conversion efficiency. In addition to photon recycling, facilitated by spectral filters, the cells' junction is externally biased to impart a positive photonic chemical potential. This enhances the spectral intensity due to a higher apparent temperature and an increased entropy content. Consequently, it raises the thermal-to-electric energy conversion efficiency to 49% in a real-world scenario and up to 56% in an ideal case. Arbitrage is introduced into this power plant by incorporating an electric grid heater in the system, which bypasses solar heating. It stores electric energy during off-peak hours and provides it during on-peak hours. In this research, financial analysis is carried out using GAMS, and an estimated arbitrage of up to $920/kW-year is achieved from the electricity grid in Pennsylvania, New Jersey, and Maryland (PJM). The thermal battery in the system is also compared with other energy storage devices, proving it to be advantageous compared to Li-Ion and lead-acid batteries, which exhibit higher unit energy storage and conversion costs.