Vattenfall has awarded Fluence Energy the contract to develop the Brunsbüttel battery storage project in Germany. With a capacity of 254 MW and over 1,000 MWh, the facility will rank among the country’s largest and marks the most ambitious storage project the Swedish utility has ever undertaken.
The agreement signed between the two companies covers a full turnkey delivery by Fluence: engineering, procurement, construction, commissioning, and long-term service support are all included in the contract. The chosen technology is the Gridstack Pro 5000 platform, a utility-scale storage solution integrating battery systems, power conversion equipment, and an energy management system designed to support grid resilience and renewable energy integration. The system is configured for a four-hour discharge duration.
Construction is scheduled to begin in 2027. Commissioning and connection to 50Hertz‘s 380 kV transmission grid are expected by the end of 2028. The selected site is the former Brunsbüttel nuclear power plant in Schleswig-Holstein, northern Germany, which is currently being decommissioned. The choice of location is deliberate: the site already boasts high-voltage grid connection infrastructure, a direct legacy of the nuclear facility that supplied power to the region for over forty years.
For Vattenfall, this project nearly doubles the company’s operational storage capacity, which currently stands at 150 MW in operation and 120 MW under construction. Most of the Swedish group’s other storage assets are co-located with solar or wind farms. Brunsbüttel breaks that mould: it is a standalone facility, designed to operate directly on the energy market and provide grid flexibility independently. Julian Jansen, VP and Managing Director of Fluence Germany, noted that the partnership with Vattenfall now spans eight projects across three European countries. Fluence has already delivered more than twenty storage projects in Germany.
Germany’s storage market is being driven by the rapid expansion of renewables and the growing need to balance an increasingly variable grid. A 1 GWh facility connected directly to the 380 kV transmission network carries significant weight in this context. If timelines are met, Brunsbüttel will come online at a point when Germany will need even greater flexibility to manage the peaks and troughs of wind and solar generation. For Vattenfall, it means cementing an active role in Europe’s energy transition well beyond conventional power generation.
