A GBP10 Million Round For Batteries That Last Days, Not Hours

Certain Energy, an Imperial College London spinout founded in 2017 as RFC Power by Professor Anthony Kucernak of the Department of Chemistry and Professor Nigel Brandon of the Department of Earth Science and Engineering, announced a GBP10 million Series A on August 26, 2026. The British Business Bank led the round with GBP3.5 million, joined by Centrica, Temasek Trust's Catalytic Capital for Climate and Health, and fellow Imperial spinout Ceres Power. The company operates out of the I-HUB on Imperial's White City campus in London.

Why Manganese, Not Vanadium

Certain Energy's batteries combine the mechanics of a flow battery with a fuel cell, converting electrical energy into chemical energy and back again by pumping liquid electrolyte through a stack. The choice of metal is the point: manganese is the 12th most abundant element in the Earth's crust, cheap and geographically widespread, unlike vanadium, the metal most of today's commercial flow batteries depend on and one whose limited, concentrated supply keeps costs high.

The bigger structural advantage is duration. Because the electrolyte and the power-converting stack are physically separate, storage duration scales just by making the electrolyte tanks bigger, stretching from hours to days without adding more of the expensive electrochemical hardware. Lithium-ion cannot do this cheaply: extending its duration means buying more cells, so cost rises roughly in step with hours stored.

What Comes Next

Certain Energy says the funding will go toward scaling up for volume production, building a megawatt-hour-class grid-connected demonstrator in India, expanding its UK research facilities, and building out supply chain infrastructure. "The transition to a decarbonised energy system requires affordable, long-duration energy storage," said Professor Kucernak. CEO Dr. Tim von Werne put it more bluntly: "Long-duration storage is the missing piece of the clean energy system."

The Bottleneck Behind Europe's Grid Squeeze

Long-duration storage is not a side technology, it is the specific gap behind the grid volatility Servola has already reported this week: European grid operator data shows solar has stabilised average supply while peak prices in constrained markets like Hungary have still spiked roughly tenfold, because there is nowhere cheap enough to bank surplus midday power for the evening demand peak. A state development bank co-leading a battery round rather than a purely private fund is a signal that the UK now treats duration, not just capacity, as public infrastructure worth derisking.

For any EU or UK business exposed to grid volatility, whether a manufacturer, a data centre operator, or an EV fleet running on time-of-use tariffs, the practical takeaway is that lithium-ion's cost curve favours short bursts, typically up to about four hours, while a tank-scaled chemistry like this one is built for exactly the multi-hour to multi-day gaps that spot-price spikes come from. It is not yet a product you can buy off the shelf, Certain Energy is still scaling toward volume production, but it is the category worth tracking before signing a long-term storage contract.

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