Investigating applications of energy storages for the integration of renewables in the distribution grid — View from a distribution grid operator

The electric utility of the city of Zurich, ewz, expects the grid load to receive additional intermittent components due to distributed generation and electric vehicles. Although the distribution grid generally has reserve capacity to cope with altered and additional loading, local temporary congestions are probable - especially during peak production and peak demand. Instead of the conventional method, grid reinforcements, battery energy storage systems (BESS) have the potential to mitigate the congestion by shifting the peak loads. Therefore, the investigations in this paper comprise the utilization of BESS as grid components. Three applications of BESS in the distribution grid and their economic aspects are presented in this paper. A pilot project is planned to demonstrate the feasibility of the applications and to gain experience with BESS.