Uniper Breaks Ground for 50MW Battery Energy Storage in Wilhelmshaven

Germany's Uniper SE and Slovenia's NGEN energetske rešitve d.o.o. have begun construction for a 50-megawatt (MW) battery energy storage project on the site of Uniper's former coal power plant in Wilhelmshaven, Germany.

"The battery energy storage system in Wilhelmshaven will balance out short-term fluctuations in the power grid caused by the feed-in of wind and solar energy in the future", a joint statement said. "In this way, the system will sustainably strengthen the integration of renewable energies as well as grid stability".

Olaf Lies, minister-president of the state of Lower Saxony, said in the statement, "The project exemplifies the next phase of the energy transition: the shift toward an integrated, digitally controlled energy system in which different technologies work together intelligently".

The partners expect to put the project into service by yearend.

"The battery storage facility is part of Uniper's Energy Transformation Hub Nordwest (ETHNw) and, following the Voslapper Groden PV park, is the second project in Wilhelmshaven to now enter the implementation phase", the statement said. "Within the ETHNw, Uniper is bringing together major projects with the aim of establishing an integrated hydrogen infrastructure in conjunction with renewable energy facilities".

The solar project on the ash landfill of the former coal plant will generate about 17,500 MW hours a year, enough to power up to 4,500 households based on an average household consumption of about 3,300 kilowatt hours per annum, according to Uniper.

Commissioning for the solar project is targeted for the first half of 2026.

In Wilhelmshaven, Uniper also plans to build a 1-gigawatt electrolyzer that would be powered by offshore wind.

Last year Uniper and thyssenkrupp Uhde GmbH signed a "framework agreement" for the construction of six commercial ammonia plants toward the establishment of a scalable hydrogen import terminal in Wilhelmshaven.

The agreement licenses thyssenkrupp Uhde's ammonia cracking technology to the power and gas utility. It covers up to six plants with a combined capacity of 7,200 metric tons of ammonia per day.

"The license package includes engineering, services and the supply of main equipment and catalysts", a joint statement said November 26, 2025.

"Uniper is currently driving forward the pre-FEED (front-end engineering and design) for a commercial plant at its Wilhelmshaven site. This pre-FEED phase will establish the design basis for the project, define its scope in more detail, further review its technoeconomic feasibility and reduce its uncertainties and risks".

Uniper expects to launch the FEED phase by yearend 2026.

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