Swedish renewable energy developer Flower has officially started construction of a landmark utility-scale battery energy storage system in Hamburg’s Bergedorf district, with a formal groundbreaking ceremony held on Wednesday. Scheduled for full commissioning by the end of 2028, the 100 MW / 400 MWh four-hour storage asset marks a key milestone for urban energy storage in Germany.

The project is recognized as the largest battery storage scheme within a major German city and stands as Flower’s biggest self-developed project to date. To date, the company’s battery storage portfolio mainly covers capacities ranging from 6 MW to 100 MW, with its first batch of storage projects set to enter commercial operation in early 2027. Flower’s total battery storage development pipeline across Germany has already exceeded 300 MW, laying a solid foundation for its expanding renewable energy footprint in the country.

Engineered to strengthen grid stability, the new four-hour-duration battery system will effectively balance volatile power output, facilitating the integration of solar and wind power generation peaks into Germany’s national energy grid. Local investment agencies provided critical site selection and pre-construction support, ensuring the smooth launch of the flagship project.