Performance analysis of a novel PV/T hybrid system based on spectral beam splitting

Photovoltaic/thermal (PV/T) hybrid utilization is a promising method for efficient solar energy harvesting. However, a low operating temperature is required for photovoltaic (PV) conversion to make PV efficiency at a high level, while a relatively high operating temperature is preferred for photothermal (PT) conversion to improve the quality of collected heat, which causes a temperature conflict and induces certain limitations on the efficiency and scale promotion of PV/T. Herein, a novel PV/T system is proposed based on the spectral beam splitting and serial thermal circuit to decouple the power generation and heat collection, which aims to reduce the intrinsic temperature conflict and improve efficiency. A combined thermal-electrical model of the PV/T system is developed and parametric analysis is performed. Predicted results show that the temperature of the solar cells is 7.7 degrees C lower than the outlet water temperature in the novel PV/T system, demonstrating the temperature-decouple effect. Compared with the traditional PV/T system, the outlet water temperature is 3.9 degrees C higher and the solar cell temperature is 9.4 degrees C lower in the proposed system, showing a comprehensive efficiency improvement of 17.9%. In summary, this work provides an alternative way for efficient PV/T utilization by decoupling the operating temperature of PV and PT processes.