June 20, 2025: Construction of an 800 MW/1.6 GWh flow battery has been launched on the borders of three European countries, Flow Batteries Europe (FBE) announced on June 17.

The system, sited at the electric grid interconnection point on the borders of Germany, France and Switzerland, is believed to be the world’s biggest flow battery and will help stabilize electricity flows across the countries, FBE said,

Leaders from FBE and the private equity-backed FlexBase Group met in Laufenburg, Switzerland to mark the launch.

The flow battery system, on a 20,000 m2 site, will be able to store energy for hours or even days, to maintain grid stability during periods of low wind and solar output, FBE said.

The Laufenburg facility will showcase one of the safest energy storage technologies available — non-flammable, non-explosive, and free from critical raw materials such as lithium or cobalt, the association said.

FBE secretary general Anthony Price, said it was now important for regulatory frameworks to support long-duration storage technologies such as flow batteries.

Studies by the German Institute for Economic Research highlight that 351 TWh of long-duration storage may be required to navigate prolonged renewable energy shortfalls — even with cross border grid interconnection, he said.

“The collaboration with FBE is an important step for our project and FlexBase as a company, said Marcel Aumer, group CEO and co-founder of FlexBase Group.

FBE is convening a joint working group to develop policy recommendations, which will include experience and information from the Laufenburg project. This and trends in the flow battery sector will be discussed at the International Flow Battery Forum in Vienna from June 24-27. Batteries International will be attending.