Topsoe, a Danish electrolyser firm, has partnered with UK-based Carbon Neutral Fuels to advance the production of sustainable synthetic aviation fuel (eSAF) using solid oxide electrolyser cell (SOEC) technology. The partnership will see Topsoe deliver 120MW of green power to Carbon Neutral Fuels’ Project Starling in Workington, UK, marking the first commercial application of Topsoe’s SOEC technology for eSAF production. The plant is expected to produce 25,000 metric tonnes of e-SAF per year, with construction planned for 2028 and operations expected to begin in 2031, pending a final investment decision.
The project was awarded the largest e-fuels grant from the UK Government’s third Advanced Fuels Fund in July 2025. The partnership aims to reduce lifecycle emissions by 89% compared to fossil jet fuel, making a significant contribution to the UK’s climate targets. The electrolyser stacks for the project will be delivered from Topsoe’s SOEC manufacturing facility in Denmark, with first deliveries expected in 2028.
The Starling project is currently in the Front-End Engineering Design (FEED) stage, and once operational, it will be a significant step towards decarbonizing the aviation industry. The project’s success is also expected to pave the way for the development of a commercial-scale eSAF market. The UK government has confirmed that its revenue certainty mechanism for SAF will be funded through a levy on aviation fuel suppliers, providing a crucial funding mechanism for the industry.
The partnership between Topsoe and Carbon Neutral Fuels is a significant development in the eSAF market, which has been gaining momentum in recent years. The European Commission has announced a €2.9 billion investment in sustainable fuels by 2027, and companies such as Finnish technology firm Liquid Sun are launching pilot plants to produce eSAF. However, the funding of SAF production remains a challenge, with competitive pricing being a precondition for scale. The UK government’s revenue certainty mechanism is expected to provide a boost to the industry, enabling companies to develop commercial-scale eSAF production facilities.