Heating performance of a novel solar–air complementary building energy system with an energy storage feature

Abstract

To compensate for the defects of the air source heat pump at low temperatures, we propose a novel solar–air complementary energy system for buildings that included an energy storage feature. This system uses heat released by the water solidification process as a low-temperature heat source for the heat pump, while utilizing air as an auxiliary energy source. While the heat storage tank supplies the building during the day, the energy in the ice storage tank is restored by collecting photovoltaic waste heat from photovoltaic photothermal (PV/T) modules or by using air energy to melt stored ice. This study evaluated the heating performance of the system in winter by analyzing storage and release of heat as well as storage and melting of ice. The results show that for heat storage by ice mode, the average coefficient of performance (COP) of the heat pump was 2.60 and that of the proposed system was 2.03. For ice melting by solar mode, the average heat collection efficiency of the PV/T module was 35.3%. An optimization strategy for system operation was provided, and the economy of the system was analyzed. The system exhibited good operational stability and reduced the peak power grid load, thus providing a novel energy supply solution for cold regions.