The UK has one of the most developed policy architectures for power-to-liquid (PtL) SAF in Europe. However, it also has zero PtL SAF volumes produced under its own mandate to date. The disconnect and whether we are likely to see PTL-SAF growth in the UK is addressed in the following article.  

The supportive case 

The UK government has built a comprehensive framework to support e-SAF:  

• SAF Mandate – live since January 2025, with a dedicated PtL obligation starting at 0.2% in 2028 and rising to 3.5% by 2040 ​[1, 2]​ 
• Revenue certainty mechanism (RCM) – a contract for difference (CfD)-style strike price contract modelled on the power sector, established under the SAF Act 2026 ​[3]​. The RCM is open to all SAF production technologies except HEFA-based biofuels, providing a clear signal that the PtL route is an intended beneficiary ​[4]​ 
• Hydrogen Allocation Rounds (HAR), a government funding mechanism to support low carbon hydrogen production across several rounds. HAR3 confirmed for 2026 (up to 1.5 GW) and HAR4 for 2028 ​[5]​ 
• Advanced Fuels Fund (AFF) – provided grant funding to first-of-a-kind commercial and demonstration-scale projects producing SAF ​[6]​ 
• Low carbon fuels fund – supersedes the AFF and will provide £219 mil between 2026-2027 and 2029-2030 to support low-carbon fuel projects ​[7]​ 

The project reality check  

Aside from announcements, the project pipeline exists but no projects have reached FID, with the most advanced projects current in FEED. The UK produced SAF volumes totalling 370 million litres in 2025, all produced by bio-based pathways and none via the PtL route.  

Table 1: Selected UK PtL SAF projects 

Project	Pathway	Stage	Ref.
SkyFuel (ETFuels)	Methanol-to-Jet	FEED, class III cost estimate due	​​[8]​
Eq.flights (equilibrion)	Nuclear-powered PtL	Pre-FEED	​​[9]​
Project Starling (Carbon Neutral Fuels)	PtL with DAC	FEED, targeting FID mid-2027	​​[10]​

 

Difficult economics  

The cost stack for PtL-SAF is unforgiving relative to HEFA:  

• Green hydrogen remains the dominant cost driver for PtL-SAF production and remains relatively high compared to blue and grey hydrogen due to high renewable power feedstock prices 
• CO2 feedstock sourcing (DAC vs. point-source biogenic) adds a second variable cost layer with limited domestic supply at scale  
• The SAF Mandate buy-out price sits at £5.00/litre for the PtL obligation specifically, which sets a rough ceiling on what RCM strike prices need to beat to pull investment rather than just avoid penalty ​[2]​ 

Competing demand 

Green hydrogen isn’t sitting idle waiting for aviation to claim it:  

• HAR3 and HAR4 allocation is not ring-fenced for aviation offtake; it competes directly with other applications such as industrial and heat decarbonisation processes 
• The UK’s original 10 GW low-carbon hydrogen ambition already exceeded the government’s own demand analysis for 2030, meaning allocation rounds are being run into a market where the supply-demand match is contested even before aviation enters the queue ​[11]​ 
• Grid connection queues and curtailment access add a further layer of competition for the cheapest power, again shared across sectors rather than allocated to PtL specifically

RCM strike prices can de-risk revenue. They cannot guarantee the hydrogen shows up on time or at the assumed cost, and that’s a distinct risk that doesn’t get retired by the same mechanism. 

Uncertainty signal  

In June 2026, DfT opened a call for evidence stress-testing its own SAF Mandate, specifically asking whether enough non-HEFA and PtL fuel will be available to meet the 2027-2028 requirements ​[7]​. Government was explicit that it isn’t trying to weaken the mandate’s targets ​[7]​. But the fact that the department felt the need to ask the question, roughly 18 months after the mandate came into force, is itself informative. 

It is worth noting too that the UK’s PtL target (3.5% by 2040) is already lower than ReFuelEU’s equivalent (10% by 2040). The UK isn’t just behind on delivery; it set a lower bar to begin with ​[2]​. 

Verdict 

The mechanisms in place in the UK are real, increasingly specific, and arriving faster than most of Europe, however, three consultations are still open as of mid-2026 (RCM levy design, contract allocation detail, and the mandate review itself), and the DfT (those running the policy) is openly questioning whether its own supply assumptions hold. 

Policy intent has never really been the binding constraint here, rather hydrogen availability, grid connection timing, and whether RCM strike prices land high enough to cover the high production cost of PtL-SAF. Until HAR3 results land and RCM allocation rounds open, PtL-SAF growth in the UK is a 2028-onwards story at the earliest, and even that depends on projects currently in FEED reaching FID within the next 12-18 months. 

 

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References 

[1]	Norton Rose Fulbright, “A new sustainable aviation fuel mandate: The UK Government’s latest step in supporting the decarbonisation of the UK aviation industry,” Norton Rose Fulbright, May 2024. [Online]. Available: https://www.nortonrosefulbright.com/en/knowledge/publications/b5f9f70c/a-new-sustainable-aviation-fuel-mandate. [Accessed 6 August 2026].
[2]	Climate Catalyst, “Alternative aviation fuel policy in the UK,” Climate Catalyst, July 2026. [Online]. Available: https://climatecatalyst.org/learning-hub/sustainable-aviation-fuel-policy-in-the-uk/. [Accessed 6 August 2026].
[3]	Watson Farley & WIlliams, “The UK Sustainable Aviation Fuel Act 2026: Enhancing revenue certainty for clean aviation investment,” Watson Farley & WIlliams, 18 June 2026. [Online]. Available: https://www.wfw.com/articles/the-uk-sustainable-aviation-fuel-act-2026-enhancing-revenue-certainty-for-clean-aviation-investment/. [Accessed 6 August 2026].
[4]	King & Spalding, “UK Revenue Certainty Mechanism for Sustainable Aviation Fuel,” King & Spalding, 17 February 2026. [Online]. Available: https://www.kslaw.com/news-and-insights/uk-revenue-certainty-mechanism-for-sustainable-aviation-fuel. [Accessed 6 August 2026].
[5]	Protium, “What is the Hydrogen Allocation Round?,” Protium, 25 July 2025. [Online]. Available: https://protium.green/what-are-the-hydrogen-allocation-rounds/. [Accessed 6 August 2026].
[6]	Department for Transport, UK Government, “Advanced Fuels Fund (AFF) competition winners,” Department for Transport, UK Government, 22 July 2025. [Online]. Available: https://www.gov.uk/government/publications/advanced-fuels-fund-competition-winners/advanced-fuels-fund-aff-competition-winners. [Accessed 6 August 2026].
[7]	M. Simonovska, “UK launches review of future SAF supply as concerns grow over non-HEFA availability,” Fastmarkets, 30 June 2026. [Online]. Available: https://www.fastmarkets.com/insights/uk-launches-review-of-future-saf-supply-as-concerns-grow-over-non-hefa-availability/. [Accessed 6 August 2026].
[8]	ETFuels, “ETFuels awarded UK government grant to develop methanol-to-jet facility,” ETFuels, 23 July 2025. [Online]. Available: https://www.et-fuels.com/article-etfuels-awarded-uk-government-grant-to-develop-methanol-to-jet-facility. [Accessed 6 August 2026].
[9]	Kent, “Kent collaborates on Pre-FEED study for Eq.flight demonstration plant,” Kent, 18 February 2026. [Online]. Available: https://kentplc.com/news-insights/kent-collaborates-on-pre-feed-study-for-eq-flight. [Accessed 6 August 2026].
[10]	Carbon Neutral Fuels, “Project Starling,” Carbon Neutral Fuels, 2026. [Online]. Available: https://www.carbonneutralfuels.com/projects/project-starling. [Accessed 6 August 2026].
[11]	Clean Air Task Force, “Recalibrating UK hydrogen towards a demand-led, systems-based approach,” Clean Air Task Force, 17 November 2025. [Online]. Available: https://www.catf.us/resource/recalibrating-uk-hydrogen-towards-a-demand-led-systems-based-approach/. [Accessed 6 August 2026].