Germany's New Mega-Battery Projects Set to Boost Grid Stability by 2027
Two municipal energy providers, Mainz Stadtwerke AG and ESWE Versorgungs AG, are implementing two projects in partnership with battery storage specialist Intilion: a 67.7-megawatt-hour (MWh) battery system with 22.7 megawatts (MW) of output in Mainz's Ingelheimer Aue and a 33.8 MWh/11.3 MW facility in Wiesbaden.
For the Mainz project, the client is Kraftwerke Mainz-Wiesbaden AG (KMW), a joint subsidiary of Mainz Stadtwerke and ESWE. In Wiesbaden, Intilion is working on behalf of ESWE Bioenergie, which operates a biomass-fired combined heat and power plant.
Both battery storage systems belong to Intilion's "Scalecube" product line and are designed as modular units, each consisting of containerized batteries with 5.6 MWh of capacity. A total of 18 modules will be deployed. According to Intilion, construction began in January, with commissioning scheduled for February 2027 in Wiesbaden and March 2027 in Mainz.
Intilion is serving as the system integrator, overseeing planning, implementation, trial operation, final system testing, and startup. The contract also includes long-term service and monitoring. A 15-year "Premium Service Package" has been agreed upon, guaranteeing 97% availability. The two facilities will primarily support energy trading but can also provide primary and secondary balancing power.
