RWE develops 700 MWh battery at former nuclear power plant site in Germany

The dust had barely settled from Saturday’s demolition of the cooling towers at the former Gundremmingen nuclear power plant when RWE signaled its commitment to shaping Germany’s energy future. On Wednesday, in the presence of Bavarian Minister-President Markus Söder (CSU), the company broke ground on a new 400 MW/700 MWh battery storage facility.

RWE announced on Wednesday that it will use the existing grid connection of the decommissioned nuclear plant for the project, which represents an investment of approximately €230 million.

Over the coming months, RWE plans to install more than 200 containers housing around 850,000 lithium iron phosphate battery cells. These will be paired with over 100 ultra-fast inverters capable of supplying or absorbing electricity within milliseconds. The facility is scheduled to begin commercial operation in early 2028, helping to stabilize the electricity grid.

RWE describes the project as Germany’s largest battery storage facility to date. That title may be short-lived, however: Eco Stor is set to break ground next week on a 300 MW/716 MWh battery energy storage system in Förderstedt, Saxony-Anhalt. Meanwhile, Ads-Tec has announced plans for an even larger storage project – 1 GW/2 GWh – expected to come online in 2029.

At the Gundremmingen site, near the border between Bavaria and Baden-Württemberg, RWE intends to further utilize the existing infrastructure of the former nuclear site. Plans include a 55-hectare photovoltaic plant, with construction scheduled to begin next year, as well as a new gas-fired power plant.

Earlier this week, RWE also unveiled plans to build a hydrogen-capable combined cycle gas turbine (CCGT) power plant with a capacity of around 850 MW at its Voerde site in North Rhine-Westphalia. The company aims to participate in the Federal Ministry for Economic Affairs and Climate Action’s upcoming tenders for reserve power plants.

“RWE is preparing diligently to participate in the tenders and to begin construction of the Voerde plant promptly after being awarded the contract,” the company said on Monday.

Back in 2024, RWE commissioned a consortium of GE Vernova and Tecnicas Reunidas to initiate the permitting process for the Voerde project. The power plant will be technically capable of operating with at least 50% hydrogen from the outset and is expected to begin generating electricity in 2030. Its strategic location also connects directly to Germany’s core hydrogen network, enabling a full conversion to hydrogen in the future.

From pv magazine Germany