EnBW has proposed a 400MW/800MWh battery energy storage system (BESS) at its former Philippsburg nuclear power plant site in southern Germany. The project aims to support grid stability by storing surplus renewable power and releasing it during peak demand periods.

The proposed system would be one of the largest battery storage facilities in Germany. The project is awaiting a building permit and a final investment decision. If approved, construction could begin soon, with operations targeted for mid-2027.

The site, currently being decommissioned, is located near a major TransnetBW substation linked to the Ultranet transmission corridor, which channels wind power from northern to southern Germany.

Peter Heydecker, board member for sustainable generation infrastructure at EnBW, emphasized the need for short-term flexibility to balance variable renewable generation with electricity demand. He noted that battery systems will work in tandem with hydrogen-ready gas power plants to ensure grid reliability.

The land designated for the battery system is separate from nuclear decommissioning infrastructure, allowing the project to proceed independently.

This initiative follows EnBW's ongoing 100MW/100MWh battery build in Marbach and complements a pumped hydro storage project launched in 2023.