Simulation study on characteristics of photovoltaic/thermal combined dual-source heat pump with electrical energy storage system

Considering the mismatch between residential energy use time and power generation time, in order to effectively utilize solar energy, this study integrates a lead-acid battery as an energy storage device into a photovoltaic/thermal combined dual-source heat pump (PV/T-DSHP) system, forming a PV/T-DSHP with electrical energy storage (EES) system. Taking a residence in Shanghai as a case, the performance of this system during the heating season is simulated and compared with that of a conventional PV/T-DSHP system. The evaluation of energy utilization is conducted using two indicators: solar fraction and self-consumption ratio. Compared with the conventional PV/T-DSHP system, the PV/T-DSHP-EES system reduces total grid electricity supplementation by 67.03%, decreasing dependence on the grid. Additionally, the average solar fraction and self-consumption ratio of the system applied to the residential building are 0.68 and 0.84, respectively, representing increases of 28.31% and 31.25% compared with the conventional PV/T-DSHP system, effectively enhancing solar energy utilization efficiency during the heating season.