Performance study on photovoltaic/thermal solar-assisted heat pump system

This paper reports the energy and exergy performance of a photovoltaic/thermal solar-assisted heat pump system (PV/T-SAHPS) with different solar radiation levels. From the heat pump, the solar evaporator/collector extracts the thermal energy required, while the cooling effect of the refrigerant reduces the working temperature of the PV cells. Therefore, this integrated PV/T-SAHPS exhibits a relatively high thermal performance with improved coefficient of performance (COP) and PV efficiency. The Engineering Equation Solver tool embedded with the Hottel–Whillier equation was used to stimulate the system to quantify the enhancement of heat transfer due to the use of a refrigerant (R134a). Simulation results indicated that the maximum efficiency of the hourly electricity generation of the PV system could reach 11.56% at 1000 W/m², the average electrical efficiency was 11.88%, and the maximum efficiency of the hourly thermal generation was 88.68% when the solar irradiance variation ranges from 300 to 1000 W/m². The maximum PV panel temperature was 35.68 °C at 14:00. The average values of COP and COP_ex were 6.14 and 1.49, respectively. These result indicated that the heat pump system performance is relatively high.