RWE Begins Construction of 236 MW Battery Energy Storage System at Hambach Mine in Germany

RWE has started construction of a 236 MW/470 MWh battery energy storage system (BESS) at the Hambach opencast mine in Germany, further expanding its large-scale energy storage portfolio to support the country’s renewable energy transition.

The battery storage facility is being developed near the village of Niederzier in the Düren district. Preparatory work on the three-hectare site began at the end of 2025, and the first of 128 lithium-ion battery containers has already been delivered. The project is expected to become operational in 2027.

Once commissioned, the facility will have an installed capacity of 236 MW and an energy storage capacity of 470 MWh. The battery system is designed to stabilise the electricity grid by providing balancing energy and will also support future grid services, including inertia, helping integrate increasing volumes of renewable energy.

Nikolaus Valerius, CEO of RWE Generation, said the Hambach project forms part of the company’s broader battery storage expansion programme in Germany.

“In Germany alone, RWE is currently building large-scale storage facilities with a capacity of around 1.7 gigawatts. The battery storage facility in Hambach is also a powerful partner for wind and solar power. It will balance out fluctuations in the electricity grid in a fraction of a second,” Valerius said.

Thomas Körber, Member of the Executive Board of RWE Power responsible for lignite operations, said the project demonstrates how former mining sites are being repurposed to support the energy transition.

RWE noted that the Hambach site already hosts three solar power plants with a combined capacity of approximately 50 MWac, alongside an integrated 4.1 MW/8.1 MWh battery storage system. The company is also developing a nearby 14.8 MWac solar park coupled with an 80 MWh battery storage facility in the future Manheimer Bucht development area.

Globally, RWE currently operates battery energy storage systems with a combined capacity of 1.7 GW, while an additional 2.5 GW is under construction across the United States, Europe and Australia. The company said expanding its battery storage portfolio remains a key pillar of its long-term growth strategy and its efforts to accelerate the integration of renewable energy into power systems.