Vattenfall has commissioned Fluence Energy, Inc. with the supply and long-term maintenance of a planned battery facility in Brunsbüttel. The project, which is being realised at the site of the Brunsbüttel nuclear power plant currently undergoing decommissioning, is designed with a capacity of 254 megawatts (MW) and a storage capacity of over 1,000 megawatt-hours (MWh). It is thus one of the largest battery storage projects currently in Germany and represents Vattenfall's most extensive battery project.
The facility is designed for a storage duration of approximately four hours and utilises Fluence's Gridstack™ Pro 5000 platform. The comprehensive battery storage solution includes the battery systems, associated power electronics, and an energy management system. Its operation aims to increase grid stability, promote the integration of renewable energies, and ensure reliable operation of the electricity system. Fluence is responsible for the turnkey implementation of the project, from planning, procurement, and construction to commissioning, supplemented by long-term service agreements to ensure performance throughout its lifespan.
Significance for the energy transition
According to SolarPower Europe, Germany is considered the leading battery storage market in Europe, with an addition of 6.6 GWh in 2025. Growth in this sector is significantly driven by the rapid expansion of wind and solar energy, increasing volatility of electricity prices, decreasing technology costs, and the ability to combine revenues from energy trading and grid services. These factors underscore the relevance of projects like the one in Brunsbüttel.
Claus Wattendrup, Head of Solar & Batteries at Vattenfall, emphasised that such battery storage systems make a significant contribution to the resilience of the energy system and the further integration of renewable electricity generation. He highlighted that Vattenfall, with Fluence as a partner, is creating a flexible facility that can respond to changing requirements of electricity markets and strengthens the portfolio of flexibility solutions. Julian Jansen, VP & Managing Director Fluence Germany, referred to the long-standing partnership and the shared vision of a more flexible energy system. He stated that Fluence, with over 20 realised battery storage projects in Germany, plays a leading role in the expansion of critical energy infrastructure.
Timeline and capacity expansion
The Brunsbüttel battery project is an integral part of Vattenfall's flexibility strategy and will almost double the company's existing battery capacity. Planned construction work is set to begin in 2027. Commissioning of the battery facility and its connection to 50Hertz's 380 kV grid are scheduled for the end of 2028.
