BP has led a $12.5m Series A funding round for Advanced Ionics, a Wisconsin-based start-up that has developed an electrolyser capable of producing hydrogen at a 30% higher efficiency than most technologies on the market.

The Symbion electrolyser is said to operate at extremely high efficiency, requiring less than 35kWh of electricity input per kilogramme of hydrogen when paired with an external heat source.

This compares to the 37.7kWh/kgH2 efficiency achieved by Bloom Energy’s solid-oxide electrolyser (SOE) in tests, one of the highest efficiencies on the market today.

The Symbion electrolyser is around 30% more efficient than alkaline and proton exchange membrane (PEM) electrolysers, generally considered the most mature commercially available technologies. These both require more than 50kWh/kgH2, although they generally work at lower temperatures.

Similar to SOEs, Advanced Ionics’ technology requires heat as well as electricity. However, the Symbion electrolyser can work at any temperature above 150°C, in contrast to many SOEs which need to run at 700-850°C or above.