En esta noticia In the Swiss canton of Aargau, a pit more than 27 meters deep and as long as two soccer fields houses what could be the most powerful underground battery on the planet. The project includes 2.1 GWh of storage and 1.2 GW of output power —comparable to a nuclear power plant— with the ability to inject energy into the grid in milliseconds. The Swiss company Swissgrid has already approved the first phase of connection at 800 MW.

What is the most powerful underground battery on the planet, and how does it work? The company is building the facility at the Technology Center Laufenburg in northern Switzerland. Instead of the lithium-ion batteries used in cars or cell phones, this system stores energy in tanks with a special liquid —called vanadium electrolyte— that circulates through cells to charge and discharge electricity.

The main advantage is safety: the liquid is neither flammable nor explosive. And to increase storage capacity, you simply add more tanks, without needing to redesign the entire system. Why can the 2.1 GWh battery supply 210,000 homes for 24 hours?

On May 21, 2026, FlexBase announced Invinity Energy Systems as its strategic partner. The system will start at 1.5 GWh and expand to 2.1 GWh: enough to supply 210,000 homes for 24 hours. Full commissioning is planned for 2029.

The site will also include an AI data center whose waste heat will feed a district heating network, with an estimated saving of 75,000 tons of CO₂ over 30 years. Total investment ranges from US$1.2 billion to US$6.2 billion, with projections to create 300 jobs.