German municipal utility Stadtwerke Gaggenau and energy infrastructure company Capac AG are planning a 7.5 MW/30 MWh zinc-bromine battery energy storage system on the former site of the utility’s liquefied gas plant in Gaggenau, southwest Germany. The four-hour system is scheduled to begin construction in 2027, with commissioning in 2028.
The project is scheduled to begin construction in 2027, with commissioning in 2028.
Roles and technology
Capac AG acts as general contractor, handling technical planning, procurement, system integration and construction through to commissioning. The project will use battery systems from US manufacturer Eos. Eos’ Intensity architecture uses modular battery units installed within an engineered steel support structure that allows horizontal and vertical arrangement. Its zinc-based batteries are manufactured in Pennsylvania using zinc bromide, conductive plastic and graphite felt. The non-flammable aqueous chemistry is cited as an enabler of the compact layout.
The Gaggenau project is a municipal utility-led deployment of a non-lithium long-duration chemistry. Zinc-bromine batteries are being positioned for longer operating life and lower degradation than conventional lithium-ion systems, with a different fire-risk profile.
Site and grid context
The former liquefied gas plant site provides an industrial location for the storage system. The project is described as a 7.5 MW/30 MWh system, meaning four hours of rated output. That duration places it in the medium-duration segment rather than the very long-duration range, but it still offers more storage duration than many short-duration lithium-ion systems.
Capac and Eos have previously announced a 5 MW/22 MWh zinc-bromine project in Bruchsal in June 2026, alongside a deal covering 2 GWh of storage capacity across Germany, Austria and Switzerland through 2031. The Gaggenau project adds another municipal utility customer to that pipeline.
What comes next
The project’s timeline leaves time for permitting, engineering and procurement. Its success will depend on construction execution, grid connection arrangements and the operational performance of the Eos systems. For now, the announcement confirms a planned 30 MWh zinc-bromine BESS at a former gas plant site, with Capac as general contractor and Eos as technology supplier.
The project also gives the German municipal utility segment another example of diversification beyond lithium-ion. That is significant for local utilities assessing long-term infrastructure investments and supply-chain exposure.
This article was assisted by AI analysis. Please refer to the original source for official information.