400 MWh BESS in Hamburg begins construction

Flower has broken ground on a new 100 MW / 400 MWh utility-scale battery energy storage system in the Bergedorf district of Hamburg. The Swedish developer noted that a groundbreaking ceremony was held on Wednesday, with accompanying photos in hard hats, to mark the start of construction, with the system expected to come online by the end of 2028.

According to Flower, this is the largest project of its kind within a major German city, and it also represents the company’s largest self-developed project to date. Until now, Flower has focused on battery storage projects ranging between 6 MW and 100 MW in capacity, the first of which are slated for commercial operation in early 2027. In total, the company’s current development pipeline in Germany exceeds 300 MW of battery storage projects.

The four-hour storage system will be deployed to stabilize the grid, helping to better integrate generation peaks from solar PV and wind power into the broader energy system. Flower was supported in its search for a suitable site by local investment agencies, who assisted through the critical phases leading up to the start of construction.

Engie is also involved in the project as a long-term partner of the Swedish developer. A Flexibility Purchase Agreement (FPA) has already been structured in the form of a virtual tolling agreement. Through this arrangement, Engie will manage the market trading and dispatch of the battery storage system as soon as it connects to the grid.