German utility company EnBW is set to install a 100 MW battery storage system at its Marbach power plant, aiming to enhance energy storage and grid stability in southern Germany. With a capacity of 100 MWh, the battery will be capable of meeting the electricity needs of around 12,500 households for up to 24 hours, although it will not be dedicated to a single location. Instead, its connection to the TransnetBW transmission grid is expected to significantly support regional power management.
The Marbach facility will become the largest battery storage project within EnBW’s generation portfolio, with construction planned to begin next year and commissioning expected by the end of 2025.
Michael Class, EnBW’s head of portfolio development in generation, highlighted the critical role of battery storage in managing renewable energy fluctuations. “With the increasing share of electricity from renewable sources such as wind and solar energy, it is becoming increasingly important to be able to store energy and make it available again at another time,” he noted. This type of “disposable power” is essential to maintaining a reliable electricity supply as the energy sector transitions to renewables.
EnBW’s head of battery system solutions, Arnim Wauschkuhn, explained that battery storage enables rapid response to grid demand. “They store electricity from the grid when larger amounts of electricity are available and can feed it back into the grid in seconds if necessary,” Wauschkuhn said. He added that battery storage complements other technologies, such as hydrogen-capable gas-fired power plants and pumped storage, which provide stability during prolonged low wind and solar periods, often seen in winter.
The project is also timely, with Wauschkuhn noting that declining battery costs and rising demand for short-term flexibility in energy markets have boosted the project’s profitability. “Battery modules have become significantly cheaper. At the same time, the need for short-term flexibility on the energy markets is increasing,” he said.
EnBW’s Marbach installation will feature lithium iron phosphate batteries, a cobalt-free option, and will be located on the southern part of the existing power plant. It will also leverage shared infrastructure at the site, which already hosts a grid stabilization hub for TransnetBW.
Battery storage plays an increasingly central role in EnBW’s energy projects, with systems integrated into new solar parks to support flexible energy feed-in. As EnBW continues its renewable expansion, the Marbach project highlights the utility’s commitment to large-scale battery investments for a resilient and renewable-focused energy future.
