Dynamic performance of photovoltaic thermal-heat pump system with connection configurations

Buildings account for a significant share of global energy consumption and carbon emissions, with space heating and domestic hot water being major contributors. Photovoltaic thermal (PV/T)-heat pump system offer a promising solution by generating both electricity and thermal energy, improving overall efficiency. While existing studies focus on individual PV/T collector performance, little is known about the effects of hybrid series-parallel configurations and mass flow rates on long-term operational efficiency. This study evaluates the impact of these factors on PV/T-heat pump system performance. A dynamic model combining lumped-parameter and transient heat current method was developed for a PV/T-heat pump system. It is found that dynamic response time of collectors in series is around 25–35 min. Different collector connection modes (series, parallel, and hybrid) and mass flow rates were simulated to assess their effects on system performance, including fluid and PV cell temperatures, electrical and thermal efficiency. Results show that increasing the number of collectors in series raises fluid and PV cell temperatures, reducing efficiency. Optimal performance was achieved with hybrid series-parallel configurations (N = 2, mass flow rate 0.03–0.035 kg/(m2·s)). The system's electrical efficiency was 12.01 %, and daily power output was 19.83 kWh, with COP values of 1.8 and 2.46. Hybrid series-parallel configurations and appropriate mass flow rates enhance PV/T-heat pump system efficiency, contributing to energy savings and reduced carbon emissions. Future research should focus on real-world validation.