The UK has completed the delivery of what is set to become the largest vanadium flow battery (VFB) in Europe, which will reportedly be capable of storing enough energy to power 3,000 households after sunset.

Developed by Invinity Energy Systems, a London-listed leading VFB manufacturer, the giant 20.7-megawatt-hour (MWh) Copwood VFB Energy Hub is based in East Sussex. The facility is expected to store excess solar energy and feed it back into the grid during periods of high demand.

The hub pairs 90 vanadium flow batteries with a three-megawatt solar array. This setup forms a large-scale long-duration energy storage system that can power a total of 3,000 homes daily. The project will begin operations later in 2026.

“This project is about far more than a single battery system, it is proof that Britain can build the infrastructure needed to transform the country into a clean energy superpower,” Jonathan Marren, Invinity Energy Systems CEO, pointed out.

Europe’s largest VFB

While conventional lithium-ion (Li-ion) batteries are mostly used for short bursts of storage, vanadium flow cells are made for energy shifting over longer periods. They store excess renewable electricity generated during the day and then release it overnight or during periods of peak demand.

This significantly helps stabilize the grid and reduce dependence on fossil fuels. The battery uses a water-based electrolyte and carries no fire risk. This addresses the growing public and regulatory concerns surrounding lithium-ion battery fires.

Invinity Energy Systems also said that the batteries are engineered for decades of heavy-duty cycling. This potentially gives them a longer operational lifespan than conventional battery systems.

The Copwood site is also seen as an essential demonstration project for the UK’s growing long-duration energy storage sector, which is expected to play a massive role in future renewable-heavy electricity grids.

Marren emphasized the importance of the project. “By building Europe’s largest vanadium flow battery here in Britain, and manufacturing it in Scotland, we’re showing that the clean energy transition can strengthen our energy security, cut system costs and create skilled industrial jobs at home,” he added.

Energy security push

According to Invinity Energy Systems, the delivery follows as the UK and Europe continue grappling with energy security concerns and volatile gas prices tied to the ongoing geopolitical instability in the Middle East.

“If we are serious about delivering a power system dominated by renewables, we must stop wasting the energy we work so hard to generate,” Marren continued in a statement. “Long-duration storage is the missing piece that turns intermittent wind and solar into reliable, on-demand power.

The batteries were assembled at Invinity’s facilities in Motherwell and Bathgate in Scotland, where the firm conducts manufacturing, research, as well as product development activities for UK and European markets.

The project received backing from the UK’s National Wealth Fund. It also secured grant funding from the Department for Energy Security and Net Zero through the government-supported Longer Duration Energy Storage demonstration program.

The UK’s energy regulator, Ofgem, is set to announce key decisions soon under its Cap and Floor support scheme aimed at accelerating investment in large-scale energy storage infrastructure.