From: Mercom India
Certain Energy, a U.K. long-duration energy storage company developing manganese flow batteries, has raised £10 million (~$13.63 million) in a Series A funding round to commercialize its technology and prepare for grid deployments.
The British Business Bank led the round, with participation from Centrica, Ceres Power Holdings, and Temasek Trust’s Catalytic Capital for Climate and Health.
Certain Energy plans to use the funding to scale its technology for volume production, develop a grid-connected megawatt-hour-scale energy storage system in India, expand its U.K. research facility, and establish a supply chain for future projects.
“The renewable power market is held back by its vulnerability to external factors,” said Executive Chair Mark Selby. “Last year, the U.K. 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.”
Previously known as RFC Power, Certain Energy was founded in 2017 as a spin-off from Imperial College London. Certain Energy’s flow battery uses manganese as a primary material. The system can increase its discharge duration by expanding the size of its electrolyte tanks. This configuration allows the technology to provide energy storage for periods ranging from hours to days.
The company said its technology has a round-trip efficiency of more than 75% and is designed to provide grid services, reserve capacity, and longer-duration electricity storage.
Certain Energy said its patented electrolyte is designed for a 20-year operating life with limited capacity degradation. The company claims its design and materials could reduce marginal storage costs to about one-tenth of those associated with comparable vanadium flow batteries and could also lower costs compared with lithium-ion energy storage systems.
According to Mercom’s recently released 1H 2026 Funding and M&A for Energy Storage report, venture capital funding for energy storage companies in 1H 2026 totaled $1.6 billion across 51 deals, representing a 6% YoY decline compared to the $1.7 billion raised across 36 deals in 1H 2025.
In May, CMBlu Energy, an organic solid flow battery technology developer, announced the completion of a €50 million (~$58.5 million) initial close of its Series C funding round, bringing the company’s valuation to over a €1 billion (~$1.17 billion). The round included participation from Samsung Ventures, alongside existing investors, including STRABAG SE.
