Energy Management, Optimization and Sensitivity of Dual Energy Storage Heat Pump System for a Nearly Zero Energy Building

To enhance the system energy flexibility, a dual energy storage heat pump (DESHP) system and energy management method considering air source heat pump (ASHP), photovoltaic (PV), thermal energy storage (TES) and battery energy storage (BES) is proposed based on an actual nearly zero energy residential building in severe cold regions. Considering technical performance, economic and environmental benefits as the key objectives, a multi-objective optimization is performed to determine the optimal system configuration and operational characteristics. Then the sensitivity characteristics of the parameters of electric vehicle (EV), PV, battery, ASHP and water tank are quantified. The results show that the DESHP system integrating TES and BES shows a better system performance. The EV, as a second energy storage body, which contributes 9.80% electric energy to meet building requirements. Increasing PV capacity can simultaneously enhance the flexible, economic and environmental performances of the DESHP system. While increasing battery capacity can enhance flexibility, it will sacrifice economy. The integration of EV is constrained by battery capacity. When EVs are introduced when battery capacity is abundant, it will reduce the grid interaction capability and have a negative impact on economic and environmental indicators. If the battery capacity is limited, its impact will be minimal.