As wind and solar power reshape electricity systems, the challenge is no longer simply generating renewable energy but keeping it available when the sun is not shining and the wind is not blowing. British energy storage company Certain Energy is targeting that gap with a flow battery technology designed to store renewable electricity for hours or even days. The company has now secured £10 million in Series A funding to move its manganese based system closer to commercial grid scale deployment.
From Imperial Research to Energy Storage
Founded in 2017 as a spin out from Imperial College London, Certain Energy was previously known as RFC Power. The company has spent years developing long duration energy storage technology aimed at supporting electricity grids as renewable generation becomes a larger part of the energy mix.
Its technology is designed to absorb electricity when renewable generation is high and release it when supply falls short of demand. This could help grids reduce renewable energy curtailment, improve stability and lower dependence on gas fired power plants that are often used to meet short periods of peak demand.
The latest funding 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.
A Different Approach to Long Duration Storage
Certain Energy is developing a manganese flow battery rather than relying on conventional lithium ion chemistry.
Flow batteries store energy in liquid electrolytes contained in external tanks. Electricity can be stored by changing the chemical state of the electrolyte and later released through the battery system.
One advantage of this architecture is that storage duration can be increased by expanding the size of the electrolyte tanks. This means the same basic battery technology can potentially be configured for applications requiring several hours of storage or much longer periods.
That flexibility is increasingly important as electricity grids deal with larger variations in renewable generation.
Manganese at the Centre
Certain Energy’s technology uses manganese in its electrolyte chemistry. Manganese is an abundant material and the company believes its use could help reduce the cost and supply chain challenges associated with some alternative battery materials.
The company says its patented electrolyte has been designed for an operating life of around 20 years with limited degradation. It also reports round trip efficiency of more than 75 per cent.
Certain Energy claims its approach could reduce marginal storage costs to approximately one tenth of those associated with comparable vanadium flow batteries.
If achieved at commercial scale, that cost profile could make flow batteries more competitive for applications where long storage duration and reserve capacity are more important than the very high power density required in some shorter duration applications.
Moving Toward Grid Deployment
The Series A financing will fund several major development programmes. One of the most significant is the planned construction of a grid connected MWh class storage system in India.
The company will also expand its research facility in the UK and develop the supply chain needed to support future commercial deployments.
These steps are intended to take Certain Energy beyond laboratory and development stage technology toward volume production and broader market adoption.
Supporting Renewable Heavy Grids
Long duration energy storage is becoming increasingly important as countries add more intermittent renewable generation. Solar power can create substantial daytime electricity surpluses, while wind generation can vary considerably depending on weather conditions.
Storage technologies capable of shifting electricity over longer periods can help bridge these gaps without requiring grids to rely entirely on additional fossil fuel generation or costly infrastructure expansion.
Certain Energy is positioning its manganese flow battery as one potential solution to this challenge. The company’s immediate priority is proving its technology through larger scale deployment while establishing the manufacturing and supply infrastructure required for commercial growth.
With £10 million in fresh capital, Certain Energy now has the resources to take its technology from an advanced research project toward real world grid applications in the UK, India and potentially other renewable energy markets.