Switzerland dug a hole the size of two soccer fields to install the world’s most powerful underground battery, able to release 1.2 GW in milliseconds and store 2.1 GWh at a multibillion-dollar price tag

Switzerland dug a hole the size of two soccer fields to install the world’s most powerful underground battery, able to release 1.2 GW in milliseconds and store 2.1 GWh at a multibillion-dollar price tag

Switzerland has started turning a deep construction pit in Laufenburg into something much bigger than an underground room. FlexBase is building a giant redox flow battery project in the canton of Aargau, with plans for more than 2.1 GWh of storage and more than 1.2 GW of power output in its final form, a scale the company compares with the output of the Leibstadt nuclear power plant.

The point is not simply to build a record-breaking battery. The bigger question is how Europe keeps the lights on when solar panels and wind turbines produce power on nature’s schedule, not ours. That’s where this Swiss project gets interesting, especially as electric cars, heat pumps, data centers, and the electric bill all become part of the same energy puzzle.

The project is being built at the Technology Center Laufenburg, near the Star of Laufenburg, a historic hub for Europe’s interconnected power grid. FlexBase says construction of the center began in spring 2025 and will combine battery storage with a water-cooled AI data center, offices, and laboratories.