How Grid Instability Sparked a Major Bet on This UK Battery Startup

Jan de Vries · 2026-08-26

Let's talk about a problem that's costing billions and a quiet British startup that just got a massive vote of confidence to fix it. Certain Energy, a long-duration energy storage company, just raised a cool $12.5 million in Series A funding. This isn't just another funding round—it's a direct response to a grid that's struggling to keep up with our clean energy ambitions. ### The Investors Placing Their Bets The round was led by the British Business Bank, which put in $4.3 million. They weren't alone. Big names like Centrica Energy, Ceres Power, and Temasek Trust's climate fund also jumped in. That's a serious lineup. It tells you they see something more than just a good idea; they see a necessary solution hitting the market at exactly the right time. Mark Selby, the Executive Chair of Certain Energy, put the problem in stark terms. "The renewable power market is held back by its vulnerability to external factors," he said. He pointed out a shocking reality: last year, the UK government spent about $1.9 billion just to pay renewable providers to *turn off* during peak production. If nothing changes, that cost could balloon to over $10 billion a year by 2030. Talk about an incentive to find a better way. ### A Wave of Energy Storage Innovation Certain Energy's raise is part of a much bigger trend. Across Europe, investors are pouring cash into companies that promise to make our power grids more flexible. In 2026 alone, similar energy-storage and grid-tech companies have pulled in at least $180 million. Think about that for a second. That's a lot of faith in a new generation of battery tech. - Amsterdam's Ore Energy raised $40 million for iron-air batteries. - Oslo's Photoncycle secured $16 million for seasonal storage. - Munich's encosa landed $27 million for commercial battery systems. Even in the UK, peers like Exergy3 and Gaussion have raised significant funds. The message is clear: the race to solve grid storage is on, and the starting gun has fired. ### So, What Makes Certain Energy Different? Founded in 2017 as a spin-out from Imperial College London, they've been working on a specific type of battery: the manganese flow battery. Here's the simple version of a complex idea. Our biggest challenge with wind and solar is that they don't always produce power when we need it. The sun sets, the wind stops, but our lights stay on. We need a way to stash that excess green energy for a rainy (or calm, or dark) day. That's where long-duration storage comes in. Unlike the lithium-ion batteries in your phone or electric car, flow batteries store energy in liquid tanks. Want to store more power for longer? You just make the tanks bigger. It's a brilliantly simple concept that's perfect for smoothing out the bumps in grid supply over hours or even days. ### The Manganese Advantage Certain Energy's secret sauce is their choice of material: manganese. They call it the twelfth most abundant element in the Earth's crust. The beauty of using something so common is cost. The company claims their design could slash storage costs to roughly one-tenth of similar systems that use rarer materials like vanadium. They're building a system meant to last around 20 years with minimal performance drop-off, boasting an efficiency of over 75%. This isn't about replacing lithium-ion batteries; it's about complementing them. For situations where you need to store a huge amount of energy for a long time, this could be the missing piece. As Charlotte Lawrence from the British Business Bank put it, "With grid demand and supply becoming increasingly volatile worldwide, the financial and strategic value of long-duration energy storage is clear." This $12.5 million is the fuel Certain Energy needs to move from promising prototype to a real-world tool that helps balance our grids. It's a bet on turning a critical weakness in our renewable future into a strength.