World’s Largest Vanadium Flow Battery to Rise in Switzerland

A Swiss data center campus is set to host the biggest vanadium flow battery installation ever built, pushing long-duration storage technology into a market long dominated by Chinese projects.

British-Canadian manufacturer Invinity Energy Systems has signed a construction contract with Equans Switzerland to deliver a modular system at FlexBase’s Laufenberg Technology Center in Laufenburg. The campus is planned as a large-scale data center hub requiring extremely high power reliability. FlexBase first disclosed the 500 MW vanadium battery plan in 2024 and obtained a local building permit a year later.

The installation will begin at 1.5 GWh of capacity, with the modular design allowing expansion to 2.1 GWh. According to Energy-Storage.news, no flow battery project worldwide has previously reached this scale; the largest deployments to date have been in China, where state-directed policy promoted storage diversification and supply-chain security.

The project’s site requires continuous discharge beyond eight hours — a duration window where flow chemistry holds clear advantages over lithium-ion. The key differentiators:

• Capital costs run higher than lithium-ion equivalents, yet the levelized cost of storage comes out lower over the system’s full service life
• No cell degradation, so capacity stays stable without replacement cycles
• No thermal runaway or fire risk, a decisive factor for a critical data center environment

In vanadium flow systems, energy and power are physically separated: liquid vanadium pentoxide electrolyte stored in tanks sets the energy volume, while the battery stack, pumps, and controls determine discharge rate. Scaling capacity means adding tanks and electrolyte — not duplicating power electronics as with lithium-ion.

Invinity’s globally installed fleet has now collectively delivered more than 10 GWh to customers. The Laufenburg project is expected to serve as the first proof point for gigawatt-class vanadium deployments outside Asia.

Source: Energy Storage News