Grid booster Kupferzell - largest grid battery storage system in the world

The Kupferzell grid booster, located in north-eastern Baden-Wuert­tem­berg, is setting new standards as the world's largest grid battery storage facility with a total output of 250 MW for one hour, set on an area the size of 4.5 soccer pitches (approx. 34,000 m²). The new grid booster will help reduce the operating costs of the German trans­mis­sion grid, enable more efficient use of the grid operator's existing as well as new power lines, and keep the power grid stable during trans­mis­sion line outages - within millisec­onds.

CDM Smith was involved in the approval planning and is responsible for the compre­hen­sive services for execution planning and construc­tion. As part of the execution planning, CDM Smith has crafted a 3D model (BIM) depicting the future battery storage system, with ongoing refinement slated throughout the construc­tion process.

After having received the approval for an early construc­tion start and partial completion of the detailed construc­tion planning, CDM Smith began preparatory groundworks and general site development in September 2023. In 2024, construction activities began, including the installation of foundations for the battery systems, as well as associated inverters and transformers. In addition, a control building with supporting infrastructure is being constructed, along with drainage systems, storage and cable ducts. Roadworks, external facilities, and landscaping measures are also integral parts of the project. Since 2025, the Netzbooster transformer has been installed on site. Furthermore, the first subnests have been successfully equipped with battery cubes and inverters.

Grid booster Kupferzell was already awarded the ICPMA Sustain­abil­ity Award at the ICPMA Awards Ceremony 2023. The ICPMA Award is a prestigious award that honors excellence and innovation in project management. For many years, companies and orga­ni­za­tions have been recognized for their expertise and dedication to providing outstanding solutions in the construc­tion and infra­struc­ture industry. At the award ceremony, Dr Constantin Prins (Project Management), Benjamin Bartsch and Lukas Wallrabe (both Business Development) accepted the award in the presence of our client Fluence Energy, represented by Timothy Frantz.