Certain Energy
Updated: September 27, 2026
The team
Country: UK | Funding: £10M (+)
Founded: 2017
Website: https://www.certainenergy.co.uk
Certain Energy develops hydrogen-manganese flow battery systems designed for grid-scale, long-duration energy storage. Unlike conventional batteries, the system can extend discharge duration by simply increasing the size of its electrolyte tanks, enabling storage from hours to days. According to the company, its technology achieves round-trip efficiency of more than 75%, enabling it to compete economically with lithium-ion batteries for key grid services while providing the resilience and reserve capabilities required by grids with increasing levels of renewable power.
Founded: 2017
Website: https://www.certainenergy.co.uk
Certain Energy develops hydrogen-manganese flow battery systems designed for grid-scale, long-duration energy storage. Unlike conventional batteries, the system can extend discharge duration by simply increasing the size of its electrolyte tanks, enabling storage from hours to days. According to the company, its technology achieves round-trip efficiency of more than 75%, enabling it to compete economically with lithium-ion batteries for key grid services while providing the resilience and reserve capabilities required by grids with increasing levels of renewable power.
