A Battery Energy Storage System (BESS) is an integrated system designed to store electrical energy in electrochemical batteries and discharge it at a later time when electricity is required. BESS plays a critical role in modern power systems by enabling flexible energy management and improving the efficiency of electricity networks.

By storing energy during periods of low demand or when renewable generation is high, and releasing it during peak demand or low generation periods, BESS helps balance electricity supply and demand. This balancing capability reduces stress on the power grid, minimizes the need for expensive peaking power plants, and enhances overall system stability.