UK delivers Europe's largest vanadium flow battery at 20.7 MWh

London-listed Invinity Energy Systems has completed delivery of its 20.7 megawatt-hour vanadium flow battery (VFB) system to the Copwood VFB Energy Hub located in East Sussex, England. The milestone marks a significant step forward for long-duration energy storage in Europe, as grid operators increasingly seek technologies that can store renewable energy over extended periods without significant capacity degradation.

Vanadium flow batteries differ fundamentally from conventional lithium-ion cells: they store energy in liquid vanadium electrolyte tanks, allowing capacity and power output to be scaled independently. Crucially, they can endure an virtually unlimited number of charge-discharge cycles with negligible performance loss — a major advantage for grid-scale applications where assets must operate reliably for decades.

Once commissioned later in 2026, Invinity says the Copwood project will hold the title of Europe's largest vanadium flow battery installation. The 20.7 MWh figure is substantial: by comparison, the average EU household consumes roughly 3.5 MWh per year, meaning this single system could theoretically power nearly 6,000 homes for a day on a single charge.

The project reflects a broader European push to diversify grid-scale energy storage beyond lithium-ion dominance. As solar and wind capacity continues to expand across the EU, long-duration storage technologies like VFBs are gaining traction among utilities and grid operators seeking stable, low-degradation assets to balance intermittent generation.