There are currently two types of home energy storage systems available: grid-connected and off-grid systems. The main components of a grid-connected home energy storage system include a solar array, grid-connected inverter, BMS management system, battery pack, and AC load. This system utilizes both solar power and energy storage to provide a hybrid power supply. In normal conditions, the load is supplied by the photovoltaic grid-connected system and mains power. However, during power outages, the energy storage system and the photovoltaic grid-connected system work together to supply power. The grid-connected home energy storage system is designed with three working modes. Mode 1 allows the surplus electricity generated by the photovoltaic system to be connected to the grid. In Mode 2, the photovoltaic system provides energy storage while simultaneously supplying electricity to some users. Finally, Mode 3 involves the photovoltaic system providing partial energy storage.
The off-grid home energy storage system operates independently without any connection to the power grid. Hence, there is no need for a grid-connected inverter for the entire system. Instead, the requirements can be met with a photovoltaic inverter. This system is designed to function in three different modes. Mode one caters to days when there is ample sunlight, allowing the photovoltaic system to simultaneously provide energy storage and meet the user's electricity consumption needs. On cloudy days, mode two comes into play, where both the photovoltaic system and energy storage batteries work together to supply electricity to the users. Finally, during evenings and rainy days, mode three activates, where the energy storage batteries solely supply the necessary electricity to the users.