Certain Energy, a British long-duration energy storage company developing manganese-based flow batteries, has raised £10 million in Series A funding to commercialise its technology. The round was led by the British Business Bank, with participation from Centrica, Ceres Power Holdings and Temasek Trust’s Catalytic Capital for Climate and Health (C3H).
Scaling Long-Duration Energy Storage
The funding will support volume production, development of a grid-connected MWh-class system in India, expansion of Certain Energy’s UK research facility and creation of a scalable supply chain.
Certain Energy, formerly RFC Power, was founded in 2017 as an Imperial College London spin-off. The company develops manganese flow batteries designed to store renewable energy from hours to days, helping grids manage fluctuations in wind and solar generation.
“The renewable power market is held back by its vulnerability to external factors,” said Executive Chair, Mark Selby. “Last year, the UK Government spent around £1.5 billion asking renewable energy providers to shut off their operations during peak production, and left unaddressed, the grid operator expects that to climb towards £8 billion a year by 2030. The answer is long duration energy storage and Certain Energy has the technology and now the funding to deliver highly efficient, affordable batteries, based on abundant materials, to make this a reality.”
Michael Shanks, Minister of State in the Department for Energy Security and Net Zero, said, “Homegrown clean energy is our route to more affordable bills and energy security, and storing it for when we need it most is critical. “By investing £3.5 million in Certain Energy, the British Business Bank is backing British innovation and helping develop the long-duration energy storage we need to store clean power for days, not hours, and deliver a more secure energy system.”
Manganese-Based Battery Technology
Certain Energy’s technology uses manganese, one of the most abundant elements in the Earth’s crust. Storage duration can be extended by increasing electrolyte tank capacity, while round-trip efficiency exceeds 75%. The patented electrolyte is designed for a 20-year operating life with minimal capacity degradation.
Chief Executive Officer Tim von Werne said "Long-duration storage is the missing piece of the clean energy system, and manganese flow is the technology that should win. With the British Business Bank behind us, we have the capital and the mandate to build a global champion here, turning world-class UK science into the industry the energy transition needs."
Supporting Commercial Deployment
The Series A investors highlighted Certain Energy’s potential to reduce storage costs and strengthen renewable energy infrastructure.
Charlotte Lawrence, Managing Director and Head of Direct Equity at the British Business Bank, said, “Faced with recent energy shocks, the UK needs to find ways to improve its energy efficiency and grid resilience. Certain Energy’s technology has proved it can deliver longer duration storage while reducing costs, with potential applications not only in the UK, but across the globe. Our investment will help Certain Energy commercialise and take the next steps towards deployment.”
Rob Booker, Chief Strategy and Transformation Officer, Centrica, stated: “Long duration storage is critical to managing the energy system of the future, and Certain Energy’s technology is exactly the kind of innovation needed to reduce costs and improve efficiency, while supporting a more renewables-led, intermittent power mix.”
Stuart Paynter, CFO, Ceres, commented: “Certain Energy has a combination that is rare in this sector: a low-cost, abundant chemistry and a credible, capital-efficient route to manufacturing. We’re glad to back a fellow UK innovator with global ambitions.”
Ryan Tan, Head, C3H, added: “As renewable energy deployment accelerates, the ability to deliver reliable, affordable clean power over longer durations will be critical. Certain Energy’s novel battery technology replaces traditional battery elements with earth-abundant materials such as manganese to deliver cost-effective and scalable long-duration storage performance with less environmental impact. This aligns with C3H’s focus on advancing promising climate innovations, and we see strong potential for Certain Energy’s technology to scale widely for meaningful impact.”