The plan for the grid-supportive large-scale battery storage system was already in place by spring 2022. The plan for the grid-supportive large-scale battery storage system was already in place by spring 2022. Possibly. In the end, funding was secured through a pool of investors from the East Westphalia-Lippe region. The grid operator Westfalen Weser gave the green light in November and December 2022. The permitting process proved more difficult. “That cost us three-quarters of a year,” recalls Sven Oberwemmer. Battery storage systems housed in buildings were unfamiliar territory for the authorities. Noise and fire protection, in particular, were major concerns. “We consulted the fire department about the required extinguishing system, conducted fire tests, and filled containers with smoke. Now, if you go by wind speed, there’s a real storm blowing through the container.”