Europe’s flow battery market just received a larger target than most of the sector has ever had to design around. Invinity Energy Systems has been selected by FlexBase Group to design a vanadium flow battery system of up to 1.5 GWh for Technology Centre Laufenburg, an AI data center and technology campus under construction on the Swiss-German border. FlexBase says the system could expand to 2.1 GWh in later phases. If the project moves from engineering into procurement, it would place one of Europe’s largest planned non-lithium batteries inside one of the power market’s fastest-growing load categories: AI data infrastructure. AI-generated image A concept view of a flow battery campus beside grid infrastructure. Image generated for CurrentCells. What Was Announced On May 21, Invinity said FlexBase selected it after a competitive review of flow battery manufacturers. The work begins with an engineering phase that is expected to run through 2026 and into 2027. That phase generates engineering revenue for Invinity, subject to milestones, but it is not yet the same as a full battery supply order. That distinction matters. The announcement is a design selection and strategic partnership, not final proof that 2.1 GWh of hardware will be delivered. After engineering is complete, FlexBase is expected to place a purchase order if the system design, economics, and integration plan satisfy the project’s requirements. Still, the scale is unusual. The first phase alone, up to 1.5 GWh, would be described by the companies as the world’s largest flow battery to date. The planned expansion to 2.1 GWh would make the project large enough to sit beside major lithium-ion grid storage projects in capacity terms, while serving a very different operating profile. 1.5 GWh Initial planned flow battery capacity 2.1 GWh Potential later-phase capacity 2026-27 Expected engineering window 30+ yr Flow battery design-life claim Why this is different The project is not just another grid battery announcement. It links a long-duration, non-flammable chemistry with an AI data center campus, a load type that is forcing developers to think beyond short-duration price arbitrage. Why Flow Batteries Fit This Job Vanadium flow batteries store energy in liquid electrolyte tanks rather than inside solid electrodes. Power comes from electrochemical stacks, while energy capacity scales through tank volume. That split is one reason flow systems are often pitched for long-duration, high-throughput applications where cycling stress can punish lithium-ion assets over time. FlexBase highlighted three traits in its selection: safety, cycle stability, and flexibility. Safety is the easiest to understand. Vanadium electrolyte is not flammable in the way lithium-ion battery packs can be under thermal runaway conditions. For a dense campus that combines computing equipment, electrical rooms, and battery infrastructure, that property has real design value. Cycle stability may be just as important. AI data centers are not passive buildings waiting for cheap power once per day. They can create heavy, persistent demand, and they increasingly need ways to firm renewable energy, reduce grid stress, and maintain service quality. A battery that can cycle frequently without the same degradation profile as lithium-ion could be useful if the economics survive engineering review. AI-generated image Flow battery systems separate energy storage tanks from electrochemical stack rooms, which can make duration scaling different from lithium-ion pack design. The Data Center Angle The Laufenburg project sits at the intersection of two market pressures. Europe wants more renewable power and more grid flexibility. At the same time, AI computing is adding electricity demand in places where grid capacity, land, permitting, and reliability all matter. FlexBase is trying to solve those issues as one campus design rather than as separate procurement problems. That is why the flow battery is being framed as grid support infrastructure, not just backup power. Invinity said the system would support renewable energy integration at the site and provide grid stabilization. In practical terms, that could mean charging when renewable output or grid conditions are favorable, discharging into campus load during high-value periods, and offering services that help the surrounding grid manage volatility. Energy-Storage.news reported that the design is expected to be vertically arranged, with tanks on one floor and stacks on another because of limited floor area. That detail is important. A GWh-scale flow battery in Europe cannot simply copy China’s large on-site construction model if labor and building costs differ. It has to prove that modular factory-built equipment can be integrated into a compact, high-value European site. What still has to be proven • Final procurement: The engineering award must become a full purchase order before manufacturing begins at scale. • Installed cost: Flow batteries need competitive lifetime economics, not just strong technical arguments. • Integration: The battery, data center, grid connection, and renewable supply plan have to work as one operating system. • Delivery timing: Engineering runs through 2026 and into 2027, so execution risk remains high. Why It Matters for Europe Most of the world’s largest flow battery deployments have been in China. Europe has seen pilots, commercial projects, and long-duration storage policy interest, but not many projects that force the supply chain to think in GWh terms. That is what makes Laufenburg notable even before final procurement. For Invinity, the announcement follows its delivery of modules for a 20.7 MWh flow battery project in the UK. Jumping from tens of MWh to a potential 1.5 GWh or 2.1 GWh system is not a normal incremental step. It is a test of whether modular flow battery manufacturing can scale into infrastructure-class orders outside China. For Europe’s battery market, the project also broadens the conversation beyond lithium-ion. Lithium iron phosphate remains the workhorse for most grid storage because it is cheap, bankable, and mass-produced. Flow batteries are not replacing that position soon. The question is narrower and more useful: can non-lithium systems win specific jobs where safety, long cycle life, and long duration are worth paying for? AI-generated image AI data centers are pushing battery developers toward systems that can handle high throughput, grid services, and reliability requirements at the same site. The Bottom Line The Laufenburg battery is not built yet, and investors should treat it as an engineering-stage project rather than a finished GWh-scale order. But the direction is clear. Data centers are becoming anchor customers for storage designs that need to do more than shift solar power by four hours. If FlexBase and Invinity convert the design work into a purchase order, Europe would get a rare real-world test of a massive vanadium flow battery attached to one of the continent’s most power-hungry growth sectors. That would give utilities, data center developers, and long-duration storage investors something the flow battery industry has needed for years: a high-profile project where the chemistry has to perform at infrastructure scale. The Bottom Line: Invinity’s FlexBase selection does not guarantee a 2.1 GWh buildout, but it gives flow batteries a serious European data center use case and a path to prove whether non-flammable long-duration storage can compete where lithium-ion is not the only answer.