Experimental optimization of a spectrum-splitting photovoltaic-thermoelectric hybrid system

Abstract

This paper provides a comprehensive experimental optimization of a spectrum-splitting photovoltaic-thermoelectric hybrid system. A steady-state experimental setup is established. The properties of the coupling system with different splitter cutoff wavelengths and thermoelectric device structures are tested and compared with the single photovoltaic system under the same conditions. The effects of concentration ratio, cooling water temperature, and flow rate on the coupling properties are also experimentally investigated. The results show that among the three cutoff wavelengths tested, 880 nm, 990 nm, and 1100 nm, the coupling system using the 880 nm cutoff wavelength splitter performs best with the highest output power of 1.64 W. The coupling utilization can boost the power by 49.1 % compared to the 1.1 W power of the single photovoltaic system. Effective enhancement in the coupling property can be achieved by increasing the thermoelectric leg height, elevating the concentration ratio, lowering the cooling water temperature, and enhancing the flow rate. The coupling system output power is increased by 24.2 % by raising the thermoelectric leg height from 1.0 mm to 1.5 mm. When increasing the concentration ratio from 55 to 146, the total system power improves by 65 %, and the thermoelectric power ratio of the total power rises from 15.2 % to 37.5 %. The results can be used to guide the subsequent studies and practical applications of the spectrum-splitting photovoltaic-thermoelectric hybrid system.