The world’s largest high-temperature electrolyser, deployed by steelmaker Salzgitter under an EU-funded green hydrogen project called Grinhy2.0, has achieved record efficiency levels.

The electrolyser, which was developed and manufactured by German manufacturer Sunfire, uses solid oxide electrolysis (SOE) technology and draws on waste heat from Salzgitter’s steelmaking process.

The electrolyser produced 200m³/hr of green hydrogen at an electrical efficiency of 84pc el,LHV—a measure of the energy contained within the hydrogen compared with the electricity used to make it.

More established technologies such as alkaline electrolysis (AE) or proton-exchange-membrane electrolysis typically reach efficiencies of around 60pc el,LHV.

“This is a level of efficiency that no one else has achieved before,” says project leader Simon Kroop from Salzgitter’s research group, Salzgitter Mannesmann Forschung.

84pc el,LHV – Efficiency of electrolyser

The fact they operate at high temperatures means SOE cells are significantly more efficient. The trial also used waste heat from the steelmaking process to improve efficiency.

Grinhy2.0 has received funding from the EU’s Clean Hydrogen Partnership, which is supported by the EU’s Horizon 2020 research and innovation programme, lobby group Hydrogen Europe and international non-profit Hydrogen Europe Research.

Earlier this year, Sunfire received a €60mn ($68mn) grant from the German government to support the commercialisation of SOE technology and to further develop AE to operate at a larger scale.

UK-based hydrogen technology developer Ceres Power recently announced its move into commercialising SOE units.

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Author: Stuart Penson