Solid oxide electrolysis cells to unlock renewable power potential

Researchers at Danish catalysis company Haldor Topsoe have published an article in Science magazine which suggests that solid oxide electrolysis cell (SOEC) technology can unlock the full potential of renewable power and provide climate-friendly fuels.

Electrolysis technologies play a central part in power-to-X solutions that produce climate-friendly fuels, such as hydrogen and ammonia. The company said that to meet the future needs for decarbonisation globally, electrolysis technologies must be deployed at a massive scale.

“In the article in Science, we claim that the SOEC technology holds the best promise for a wider adoption thanks to unrivalled energy conversion efficiencies,” said Rainer Küngas, Principal Scientist at Topsoe and one of the lead authors of the article. “The high operating temperature of SOECs gives rise to the two main advantages over competing alkaline and polymer-electrolyte membrane (PEM) electrolysers: more favourable thermodynamics and faster kinetics.

“It is also essential that the SOEC technology is based on scalable production methods and abundant raw materials such as nickel, zirconia and steel.”

The SOEC technology can be thermally integrated with a range of chemical synthesis processes enabling the efficient production of future fuels such as methanol and ammonia. Green ammonia, for example, can be produced from air, water and renewable electricity and become a highly attractive fuel for decarbonising the maritime sector.

The article in Science describes key developments in the SOEC technology within the past 15 years and argues that it is ready for an industrial scale-up, which is in fact already happening at a rapid pace. Researchers from Haldor Topsoe, Technical University of Denmark, Aalborg University and Energinet have contributed to the article.

The technology has moved from the R&D phase into demonstration and scale-up, and today it is on the verge of commercialisation. Topsoe said it is at the forefront of the commercialisation activities and has just shipped the world’s first unsubsidised SOEC plants that will soon start converting CO₂ into useful chemicals in Ohio, USA.

Solid oxide electrolysers: from nanoscale to macroscale. For a larger image, click here.

Topsoe is simultaneously continuing research and development activities to achieve further performance enhancements and cost reductions on cell, stack and system level.

When renewable electricity is used in electrolysis, the production of fuels and chemicals can be decoupled from fossil resources and CO₂ emissions, paving the way for an energy system based entirely on renewable energy and resources.

Image: A solid oxide electrolysis stack developed by Haldor Topsoe. Powered by electricity, the stack can convert steam into hydrogen or carbon dioxide (CO₂) into carbon monoxide (CO).