Power generator LEAG and its turnkey BESS construction partner HyperStrong have started building a 400MW/1,600MWh project in Germany, while Sunotec has done the same on a 441MWh project.
The companies announced the launch of construction on the ‘GigaBattery Boxberg 400’ battery energy storage system (BESS) project yesterday (1 September).
The 4-hour project will connect directly to the high-voltage transmission grid, and is being built on the rehabilitated area of a former lignite-fired power plant site.
It comes with the Energy Storage Summit Germany 2026 right around the corner, on 15-16 September 2026 in Berlin (use our code ESN20 for a 20% discount on tickets).
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China-based system integrator HyperStrong is building the BESS project under a turnkey contract for LEAG. It will provide the end-to-end battery energy storage solution, including its HyperBlock III liquid-cooled BESS units, electrical equipment integration and turnkey construction.
Kai Wang, UK and Ireland country manager for HyperStrong, called it the company’s ‘first full wrap EPC BESS in Europe’.
Siemens Energy meanwhile is deploying a new 380 kV switchgear system to connect the project to the grid.
After being a bit slower to BESS than some of its other peers like RWE, LEAG made two huge project announcements in late 2025: the 1GW/4GWh GigaBattery Jänschwalde 1000 with system integrator Fluence, and then the 1.6GWh project with HyperStrong.
The 4GWh project is expected to be completed in 2027/28. LEAG and Fluence started building their second project together, a smaller 100MW/400MWh system, last month.
Germany is widely agreed to be one of if not Europe’s most attractive energy storage market with huge wholesale market opportunities and numerous offtake and tolling options available to help unlock financing.
The main challenges are now around grid fees, flexible connection agreements (FCAs) and regulatory clarity, according to event speakers we’ve been hearing from ahead of the Berlin conference in two weeks’ time.
We caught up with HyperStrong’s president of technology Dr. Yang Guang in a video interview whilst at the Smarter E Europe trade show and conference in Germany in June, mainly to discuss sodium-ion technology and increasing controls on Chinese technology in Europe and the US (subscription required).
Sunotec starts building 441MWh project
In related news, system integrator Sunotec has started construction on a 100MW/441MWh BESS in Stendal, Saxony-Anhalt, Germany, with commissioning planned for Q1 next year.
The project is being built under a joint venture, Secursun, between Sunotec and developer Surenergy.
Among those attending the groundbreaking were Thomas Wünsch, State Secretary at the Ministry of Science, Energy, Climate Protection and the Environment of Saxony-Anhalt and Bastian Sieler, Lord Mayor of the Hanseatic City of Stendal.
