Device performance matching and optimization of photovoltaic-thermoelectric hybrid system

Abstract

• The effects of various factors on the device selection of the hybrid system are studied. • A device selection method of the hybrid system with broad suitability is established. • A multi-objective genetic algorithm is adopted to optimize the coupling efficiency and efficiency difference. • The two optimization objectives are proved to be negatively correlated. This paper focuses on the two critical issues of device selection and performance optimization for the photovoltaic-thermoelectric hybrid system. Theoretical models of concentrating photovoltaic-thermoelectric hybrid system and concentrating photovoltaic system are established. The impacts of varying factors on system device selection are investigated. The device performance matching mechanism of the coupling system is revealed, and a device selection method of broad suitability is proposed. The optimization of the hybrid system is conducted by adopting a multi-objective genetic algorithm with the highest coupling efficiency and the maximum efficiency difference relative to a single photovoltaic system as the optimization objectives. The results show that the minimum thermoelectric figure of merit of the hybrid system is determined only by the concentration ratio and the photovoltaic device capability when the cooling condition is fine, the thermal contact resistance is low, and the thermoelectric structure is appropriate. The proposed device selection method on the basis of these results can be well employed to select coupling devices and evaluate the system feasibility. The multi-objective optimization results reveal that the two optimization objectives are negatively correlated. Further consideration of the system economy is required to determine the compromise between the highest coupling efficiency and the maximum efficiency difference for the optimum design of the coupling system.