Last week marked the official commissioning of the Immenstadt battery system, located in the scenic region of Allgäu, southern Germany. With a storage capacity of nearly 33 MWh, it is currently the largest battery in operation in Bavaria. Beyond its scale, this project highlights how practical collaboration, structured processes, and the right digital tools can support the energy transition.

At Cellect Energy, we’re pleased to have contributed to this project by providing the software infrastructure needed to operate and manage the battery reliably and transparently. Our role focused on ensuring that all operational partners could access and work with the data they need—when and how they need it.

• Cellect Data Management: We provided the software that integrates all on-site data from the battery system, power electronics, and other components. This data is accessible to all operational partners via our versatile Cellect API.

• Cellect Platform: Green Flexibility leverages our battery asset management platform for the entire technical and commercial operation of the Immenstadt battery site, ensuring seamless operations.

One of the most notable aspects of this project is its timeline. The battery system went from an initial idea—through planning, construction, and integration—to full commercial operation in just 18 months. That’s relatively fast for an asset of this type and size.

This project wouldn’t have been possible without the vision and dedication of green flexibility and AÜW - Allgäuer Überlandwerk GmbH, who are making strides toward a sustainable energy future. Congratulations to them for building and operating the biggest battery in Bavaria!

Bringing the Immenstadt battery system to life was a collective effort—and at Cellect Energy, we’re proud to have played a meaningful role in it. Projects like this are complex by nature, and delivering a reliable software layer that integrates smoothly with all system components requires both technical precision and close collaboration.

What made this initiative especially rewarding was seeing our solutions actively supporting a project that aligns so clearly with the future of energy: smarter infrastructure, clean power, and coordinated operations. We’re especially proud of the Cellect Energy team—whose dedication, expertise, and attention to detail made this contribution possible. Their work continues to shape how energy storage systems are managed across Europe and beyond.

Whether you’re planning a new battery installation or scaling an existing one, we’re here to help.

Get in touch to learn how Cellect Energy can support your energy storage journey.