Household Photovoltaic Intelligent Power System Based on Energy Storage

A household photovoltaic intelligent power supply system was proposed to increase the on-site consumption capacity of household photovoltaics and fulfill the requirements for a comfortable and convenient living environment. The system can fulfill the requirements of household electricity, space heating, space cooling, and hot water supply throughout the year. Heating and cooling were realized using air source heat pumps (ASHP), underfloor heating, fan coil units, and energy storage water tanks, which store hot water in winter and cold water in summer. A TRNSYS simulation model of the system was created based on residential buildings in Shandong, China. Based on the simulation results and local electricity prices, the energy storage operation plan was optimized, and the economic efficiency of the system was analyzed. The results indicate that the system can meet the building′s year-round electricity consumption, maintain indoor temperatures in winter and summer, and generate revenue from photovoltaic power, yielding the maximum return on investment throughout the entire life cycle. The optimal operating schedule for the ASHP is from 09:00 to 16:00 and 22:00 to 05:00 in winter and from 07:00 to 18:00 and 22:00 to 05:00 in summer. Controllable electrical appliances were used from 10:00 to 16:00. In contrast, appliances with energy storage were used from 11:00 to 14:00 to consume and store the photovoltaic electricity. The energy-storage water tank reduces standard coal consumption by 46% compared to the case without a water tank, demonstrating a substantial energy-saving effect.