Cost optimization of battery energy storage system size and cycling with residential solar photovoltaic

In Southeast Queensland, investment in electricity infrastructure to meet peak demand, and a reduction in average demand because of high residential solar generation, has caused network under-utilization and rising electricity costs. Coupling a battery energy storage system (BESS) with solar photovoltaic (PV) allows consumers to reduce their electricity bills by storing excess solar generation to consume in peak time-of-use (TOU) tariff periods. The BESS size and cycle schedule were optimized using mixed-integer linear programming to minimize annual energy cost to residential households. The optimal size was the smallest system because of the high, size-proportional BESS costs. The optimal cycling reduced solar PV export and peak demand. The annual electricity costs with and without an optimized BESS were considered under various feed-in tariffs, TOU tariffs and PV inverter sizes. In every scenario, the BESS cost exceeded its electricity savings and was not financially beneficial to install.