Energy company EnBW has announced plans to develop a 400 MW/800 MWh battery energy storage system at its energy park in Philippsburg, located in southwestern Germany. The project is set to become one of the largest battery systems in the country and is designed to absorb excess electricity from renewable sources and release it back into the grid when needed.

According to EnBW, the facility will be capable of meeting the daily electricity needs of around 100,000 households. The battery storage system will be located adjacent to the Ultranet converter station, built by transmission system operator TransnetBW, which transports wind power from northern Germany to the south via a high-voltage direct current (HVDC) link.

“The generation capacity of renewable energy, which depends on weather conditions, must be balanced with the actual electricity demand from households, businesses, and industry,” said Peter Heydecker, EnBW board member responsible for sustainable generation infrastructure.
“Battery storage and hydrogen-ready gas-fired plants provide the flexibility we need in the system,” he added.

Philippsburg Mayor Stefan Martus emphasized the town’s longstanding role in Germany’s energy landscape:

“Philippsburg has been one of the most important energy hubs in all of Germany for half a century, and our municipality must continue to play this leading role in the future—as an anchor point and major storage site for sustainable power generation.”

The battery project is expected to be financed through revenues from the electricity market and grid services, without any government subsidies, according to EnBW. The company added that the existing grid infrastructure at the site makes Philippsburg a suitable location and simplifies development compared to a greenfield alternative.

TransnetBW is expected to provide full grid connection capacity—both for feed-in and extraction—by mid-2027. However, EnBW stated that the project is still in its early stages, with a final investment decision and planning approval yet to be made.

If approved, the system is expected to be commissioned by late 2027.