Centrica Energy and renewable energy developer Zelestra have signed a physical tolling agreement covering a 99MW/297MWh standalone battery energy storage system in Lower Saxony, Germany.
Zelestra will develop, construct, own and operate the three-hour Hilgermissen BESS, while Centrica Energy will trade and optimise the contracted capacity.
Engineering and procurement activities are due to be completed this year, with construction scheduled to start in 2027. The project is expected to enter full operation in the second half of 2028.
Under the tolling agreement, Centrica Energy will optimise the battery across Germany’s day-ahead, intraday and ancillary-services markets. The companies did not disclose the duration or financial terms of the agreement.
The battery chemistry, system supplier and power conversion equipment have also not been disclosed. Although lithium-ion remains the dominant technology for projects of this scale and duration, the companies have not confirmed that chemistry for Hilgermissen.
Lower Saxony combines a substantial industrial base, including automotive, agricultural and food-production businesses, with significant wind and biomass generation. The companies said the battery would provide flexible capacity to help integrate renewable electricity and support grid stability.
Cassim Mangerah, managing director of Centrica Energy, said: “This agreement with Zelestra is an important milestone for Centrica Energy in Germany and another step forward in delivering on our strategy. The continued growth in our German flexibility portfolio demonstrates the demand for our optimisation capabilities and further strengthens our position in one of Europe’s most dynamic flexibility markets.”
Mathias Kuenicke, CEO of Zelestra in Germany, said: “Hilgermissen adds 300 MWh of flexible capacity to one of Europe’s most connected grids and largest energy storage markets. This tolling agreement with Centrica Energy is a vote of confidence in our BESS platform, and it builds directly on the pipeline we’re growing across Germany, with more than 2 GW of solar, wind and storage projects in development.”
Centrica Energy is the energy trading and optimisation arm of UK-headquartered Centrica. It has more than 18.8GW of capacity under contract, of which more than 85% comprises renewable energy assets.
Zelestra, which is backed by investment organisation EQT, develops, constructs and operates large-scale renewable energy projects.
Photo: BESS units being installed © Zelestra
