Performance sensitivity analysis of residential photovoltaic-driven heat pumps with energy storage

Purpose This study thoroughly investigates how the performance of a PV-driven heat pump with a water storage tank and batteries is affected by various factors, including different electrical load profiles, domestic hot water (DHW) load profiles, heating elements with varying output capacities, battery capacities, and the threshold values for operating the heating elements in residential buildings. Design/methodology/approach Using a typical Australian house fitted with an integrated PV-driven heat pump and a water storage tank as a case study. Transient System Simulation (TRNSYS) is used to model the integrated system and validated using the measured hourly PV generation, house electricity consumption, and energy use of the heat pump. Findings Adjusting the electrical load profile from low to high enhances annual PV self-consumption by 12%, rising from 7% to 19%. However, the daily distribution of electrical load profiles influences the fraction of the electrical load that can be satisfied by PV energy. Variations in DHW loads can influence the PV and grid energy consumption of the integrated system, but their effect is significantly less pronounced than that of fluctuations in electrical loads, as the p-values obtained from the two-way analysis of variance for the annual PV self-consumption and self-sufficiency both exceed 0.05. The utilisation of batteries and heating elements can either store surplus PV energy or convert it into thermal energy storage for household consumption; nevertheless, the effective use of stored thermal energy is essential to prevent redundant energy storage. Originality/value These results provide researchers a better understanding of using PV-driven heat pumps with energy storage systems to attain higher levels of building electrification while providing a foundation of knowledge for residents and industry experts in determining the appropriate dimensions of the integrated system according to the energy demands of their homes.