Energy, exergy, economic and environmental analysis of photovoltaic/thermal integrated water source heat pump water heater

Abstract

The photovoltaic thermal integrated water source heat pump (PV/T-WSHP) water heater system can meet the demand for not only the domestic hot water but also the electricity production. To comprehensively analyze the benefits of the PV/T-WSHP water heater system, energy, exergy, economic and environmental analysis method was applied. A TRNSYS model of the PV/T-WSHP water heater system was developed based on the existing experimental setup, and validated by the experimental data. A combined system of single PV system and single air source heat pump water heater (PV + ASHP) system model was also built for comparison. The simulated results indicated the PV/T-WSHP water heater system had a 25.3% improvement in electrical conversion efficiency, a slightly lower EER of 3.71 and a significant reduction in annual exergy loss, comparing with the combined PV + ASHP system. In addition, the annual cost of the PV/T-WSHP water heater system was 217.7 yuan lower than the combined PV + ASHP system. The PV/T-WSHP heat water system and the combined PV + ASHP system could annually save the standard coal of 0.62 tons and 0.50 tons, respectively. This study provides an effective method to comprehensively analyze the performance of the PV/T-WSHP water heater system.