EnBW Advances Storage Strategy: Construction Begins on 100 MWh Large-Scale Battery in Marbach to Strengthen Grid Stability
Stuttgart/Marbach (Germany) - EnBW Energie Baden-Württemberg AG is continuing to expand flexible infrastructure as part of the energy transition. A key component is the use of battery storage systems to stabilize the grid. The energy company has now started construction of a large-scale storage facility in Marbach.
EnBW relies on storage as a key element of the energy transition
As part of its transformation into a sustainable infrastructure company, EnBW is also focusing on expanding battery storage as a complement to renewable generation plants and flexible generation capacity. The aim is to technically offset the increasing volatility in the power system caused by wind and solar energy and to ensure grid stability.
“Large-scale battery storage systems are indispensable for balancing fluctuating generation from wind and solar with actual electricity demand in the short term. For longer periods, hydrogen-ready gas-fired power plants can take over. The two technologies therefore complement each other ideally,” said Peter Heydecker, Board Member for Sustainable Generation Infrastructure at EnBW. “By connecting to the transmission grid of TransnetBW, the storage facility will play an important role in the entire southern German electricity grid.”
The project is also welcomed at the municipal level. Marbach’s mayor, Jan Trost, stated: “Marbach will be further strengthened as an important energy location through the construction of the battery storage system. We are pleased to contribute to security of supply in the region.”
Large-scale battery storage Marbach: technology, construction, and grid function
The new battery storage system is being built directly at the existing EnBW power plant site in Marbach. As part of the planned construction process, the ground will first be prepared using vibro-compaction to increase load-bearing capacity for the future foundations.
As the project progresses, around 264 battery cabinets will be installed, containing a total of approximately 110,000 battery cells. The system will use lithium iron phosphate (LFP) technology, which does not require cobalt and is designed for safety and longevity, particularly in stationary applications.
The system will be complemented by a new medium-voltage switchgear installation housed in a separate building. This will serve as the interface to the power grid and enable flexible grid injection and withdrawal to the transmission network of TransnetBW.
Storage as part of EnBW’s generation portfolio
The Marbach site is already integrated into EnBW’s system concept. In addition to the new large-scale storage facility, the company has been operating a grid stabilization facility there since last year on behalf of TransnetBW. This facility is not used for commercial electricity generation but exclusively for stabilizing the power system.
The storage system in Marbach is part of a broader storage expansion strategy by EnBW. The company currently operates 20 battery storage systems with a total installed capacity of over 100 megawatt-hours. In addition, projects with a combined capacity of around 1,800 megawatt-hours are under development or construction. At the same time, new solar parks are increasingly being combined with battery storage as standard to improve the integration of renewable energy into the system. EnBW is also planning another large-scale battery storage facility in Philippsburg.
Source: IWR Online, 20 Apr 2026
