Swiss company FlexBase is building a technology centre in Laufenburg, canton Aargau, whose centrepiece is a vanadium redox flow battery (VRFB) intended to help stabilise the electricity grid. If built as planned, it would be the largest installation of its kind in the world.
The planned building is 218 metres long, 80 metres wide and 30 metres high, with a 25-metre-deep structure and a blue photovoltaic facade of about 2 MW — described as one of Europe's largest PV facade areas. As FlexBase CEO Marcel Aumer notes, the solar facade is negligible compared with the battery itself.
1.2 GW and 2.1 GWh by 2029
According to the planning status reported, FlexBase intends to install 108 vanadium redox flow batteries by 2029, with a maximum power of 1.2 GW — on a par with the Leibstadt nuclear power plant — and a storage capacity of 2.1 GWh. FlexBase says that capacity equals the electricity demand of 170,000 households over 24 hours.
For comparison, the largest such facility in operation today is in China: Rongke Power announced a 1 GWh / 200 MW project that went into operation at the start of the year — significantly smaller than what is planned in Laufenburg.
Why Laufenburg
Aumer says Laufenburg is the only place to build something of this magnitude. At the "Stern von Laufenburg", the Swiss grid interconnects with the European grid, giving access to the European electricity market via more than 41 cross-border lines. He had passed through the site professionally over the past decade, and when it came up for sale in 2023 he knew "within a second" it was the right one.
Total costs are CHF 2.5 to 5 billion, funded by private wealth. Aumer, the main shareholder of FlexBase, declined to expose his investors publicly.
He describes it as a passion project that could only be realised at this location and in this way — as a campus covering numerous fields, including an AI data centre above the battery and space for start-ups.
Construction and obstacles
When the Keystone-SDA news agency visited FlexBase in mid-September, the large construction site in Laufenburg was characterised mainly by a sizable excavation pit and numerous cranes.
Aumer warns that batteries cannot be connected to the grid at will: grids are ageing and connection capacity is lacking, while expansion is complicated by objections. He aims to smooth the peaks created by renewable energy — both short-term fluctuations and the storage of daytime surplus for discharge at night — but says there is still a long way to go before 24-hour, 365-day renewable supply can be guaranteed.
This article was assisted by AI analysis. Please refer to the original source for official information.