Operational study of domestic battery energy storage system

Abstract

A battery energy storage system (BESS) has been constructed and deployed in a residential property. The BESS uses a pack of lead‐acid batteries with a centre‐tap enabling the use of a simple half‐bridge converter as the bi‐directional interface to the mains. The BESS has been used in a number of ways including solar self‐consumption, capping the demand from the mains, providing the power for a heat pump and deferral of the load from charging a battery electric vehicle. All these have proven satisfactory on the basis of measured results. Solar self‐consumption, demand capping, and load shifting in the context of the normal domestic load can be achieved with a modest battery capacity, 3 to 5 kWh, but significant deferral of vehicle charging and time shifting of the winter heat pump load point to larger batteries, over 10 kWh. On the basis of current electricity tariffs in the UK, the cost of a BESS will not be recovered but a combination of new revenue streams, new time of use tariffs, possible subsidies, and reductions in system costs would make the use of a BESS economically attractive.