Vattenfall has awarded the 254 MW Brunsbüttel BESS, which is to have a storage capacity of over 1,000 MWh, to Fluence Energy. The four-hour plant is to be built on the site of a nuclear power plant in Germany that is being decommissioned, and it is scheduled to be in operation by the end of 2028.
Snapshot
Power output: 254 MW
Storage capacity: 1 GWh
Duration: Four hours
Owner: Vattenfall
Turnkey supplier: Fluence Energy
Platform: Gridstack Pro 5000
Construction start: 2027
Operation target: End 2028
Grid link: 380 kV
Grid operator: 50Hertz
Location: Brunsbüttel, Germany
Fluence Energy, a US-based provider of energy storage systems and optimization software, has been selected by Vattenfall to deliver the Brunsbüttel BESS in Germany. Its agreement with Vattenfall also covers the long-term service of the plant. The plant has been designed for an output of 254 MW and over 1,000 MWh of storage, and it is to stand on the site of the Brunsbüttel nuclear power plant, where decommissioning is now under way. The agreement was announced from Berlin on 14 October 2026.
Fluence will deliver the four-hour facility on a turnkey basis, which means that the engineering, procurement, construction and commissioning of the plant will all be carried out by the company. The facility is to be built on its Gridstack Pro 5000 platform, which combines the battery systems, the power conversion equipment and an energy management system. Construction is expected to begin in 2027, and the commissioning of the plant, together with its connection to the 380 kV transmission network of 50Hertz, is planned for the end of 2028.
The Brunsbüttel BESS will be the largest battery project of Vattenfall to date, and it will nearly double the battery storage capacity that the company already has in operation. The project has been described by Vattenfall as a key component of its flexibility strategy, and it is expected to be among the largest BESS projects in Germany.
Claus Wattendrup, Head of Solar & Batteries at Vattenfall, said that such facilities "play an important role in strengthening the resilience of the energy system and enabling the continued integration of renewable power generation". Julian Jansen, VP & Managing Director of Fluence Germany, said that the relationship between the two companies "now spans eight projects across three European countries", and that Fluence has delivered more than 20 BESS projects in Germany.
Germany is currently the leading battery storage market in Europe, and 6.6 GWh of battery storage was added in the country in 2025, according to SolarPower Europe. The growth of that market has been driven by the rapid expansion of wind and solar power, by the increasing volatility of electricity prices and by declining technology costs, as well as by the ability of storage assets to combine revenues from energy trading and grid services.
Fluence Energy is listed on the Nasdaq, and its energy storage and optimization software is used for renewables and storage in nearly 50 markets.