EnBW Energie Baden-Württemberg AG has approved the final investment decision for a major battery energy storage system (BESS) at Philippsburg Energy Park, paving the way for the installation of one of Germany’s largest battery storage facilities. The project, which will include 400 MW of power capacity and 800 MWh of storage, will move forward without any government subsidies.

The new facility will be built on a site adjacent to the TransnetBW converter station, an integral part of the ULTRANET direct-current link transporting wind power from northern Germany to the southwest. The Philippsburg site, formerly home to two nuclear power units—now in dismantling since 2017 and 2020—continues its transformation into a major clean energy hub.

A key boost for grid flexibility

According to EnBW, the BESS will play a crucial role in strengthening Germany’s energy flexibility as the country integrates more wind and solar into its power mix.

“This investment decision is a key step in making our energy system more flexible,” said Peter Heydecker, Chief Operating Officer for Sustainable Generation Infrastructure at EnBW. “Battery energy storage systems are indispensable for balancing the fluctuating supply of wind and solar power with actual electricity demand. They are an ideal complement to hydrogen-ready gas-fired power plants, which are intended for longer deployments. The investment also boosts Philippsburg as a key energy hub.”

Construction to begin in 2026

Construction is scheduled to start in early summer 2026, with commissioning expected by the end of 2027. Once operational, the BESS will be capable of supplying enough electricity to power around 100,000 homes.

The project will be financed entirely through revenues from electricity sales and grid services that help maintain system stability and ensure reliable power supplies.