
RWE has launched construction on a 236MW/470MWh BESS in Germany, while IPP Kallista has done the same on a 193MW/386MWh system in France, supplied by Envision Energy.
RWE starts construction on 2-hour BESS in Germany
Power firm RWE has started building a 236MW/470MWh battery energy storage system (BESS) project at its Hambach open-cast mine in Elsdorf, North Rhine-Westphalia, Germany.
The first few battery container units have already been delivered, of the 128 that will be delivered, and commissioning is planned for 2027.
Thomas Körber, a member of the RWE Power Executive Board responsible for lignite: “The Rhineland mining region remains an energy hub, and that is good news. In addition to renewable energy plants, we are building storage facilities on opencast mining areas that are no longer needed. This is an important contribution to the energy transition, directly from the opencast mine.”
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RWE has already commissioned 50MWac of solar PV and a 4MW/8.1MWh BESS at the Hambach open-cast mine site.
The firm has been one of the key players in the German grid-scale BESS market in the past few years. It is building two of the largest projects in the country under-construction, at 400MW/800MWh and 400MW/700MWh respectively.
It is the latest in a string of large-scale BESS projects to have progressed to investment, financing or construction totalling 15GWh since regulators confirmed the 4 August 2029 for projects to get online and avoid charge-discharge grid fees.
RWE didn’t reveal (and never does) the BESS supplier it is using for the project. As a huge power firm present across technologies and regions, it likely has a significant degree of in-house system integration capabilities.
IPP Kallista enlists Envision Energy for France BESS
Clean energy technology firm Envision Energy will supply BESS to independent power producer (IPP) Kallista for its Neuilly-en-Thelle 193MW/386MWh project in Hauts-de-France, France. Construction started this month with commercial operation expected in Spring 2028.
Envision said the project will be powered its lithium iron phosphate (LFP) cells and “supported by the company’s 10GWh gigafactory in Hauts-de-France”. The gigafactory in Douai, built by Envision’s Envision AESC arm, has been operational since June 2025. It added that the project “combines local battery manufacturing with system integration to strengthen regional industrial capacity and enhance energy infrastructure resilience,” again implying it will be supplied by the factory.
It is the second project the two companies have partnered on, following a 120MW/240MWh one last year that was also said to be supplied by the local factory.
Landesbank Saar and BNP Paribas provided financing for the project while contractors Omexom and Skyray will build it. Power firm EDF’s Agregio Solutions will optimise its dispatch in the electricity market. It will provide balancing services to transmission system operator RTE while also participating in the wholesale energy market.
The largest BESS project currently online in France is a 240MW/480MWh one from TagEnergy, supplied by Tesla. Last week, Amarenco started building a 200MWh system.