
On January 1, 2025, the UK Sustainable Aviation Fuel (SAF) Mandate officially took effect, marking a pivotal step toward decarbonizing one of the hardest-to-abate industries. This mandate introduces progressive obligations for fuel suppliers, aiming to boost SAF production and usage within the UK’s aviation sector.
What is SAF?
Sustainable Aviation Fuels (SAFs) are renewable alternatives to traditional jet fuel, offering substantial greenhouse gas (GHG) emission reductions. SAF can be derived from:
- HEFA (Hydroprocessed Esters and Fatty Acids): Oils or fats, such as used cooking oil.
- Non-HEFA Advanced Fuels: Created from wastes and residues, such as municipal solid waste.
- Power-to-Liquid Fuels: Synthesized using renewable or low-carbon power sources.
When replacing kerosene, SAF can achieve an average of over 70% lifecycle GHG savings, far exceeding the mandate’s 40% minimum requirement.
Key Provisions of the SAF Mandate
The SAF Mandate introduces a main obligation and a Power-to-Liquid (PtL) obligation to encourage innovation and supply growth:
- 2025: 2% SAF of total jet fuel demand (~230,000 tonnes).
- 2030: 10% SAF.
- 2040: 22% SAF.
The PtL obligation begins in 2028 at 0.2% of jet fuel demand, increasing to 3.5% by 2040.
“The SAF Mandate is a cornerstone policy for decarbonizing the aviation sector, driving innovation, and setting the UK on a course for sustainable skies.”
Certificates are issued based on the GHG emissions reductions achieved, allowing suppliers to demonstrate compliance, trade certificates, or pay a buy-out price. To ensure space for innovation, the mandate includes a HEFA cap, limiting HEFA-based SAF to 71% of supply by 2030 and 35% by 2040.
Impacts and Future Outlook
By shifting obligations to jet fuel suppliers and implementing advanced fuel incentives, the SAF Mandate aligns with the UK’s net-zero targets. In 2023, 97 million liters of SAF were used, showcasing the growing momentum in this sector. The mandate is expected to save up to 6.3 megatonnes of carbon annually by 2040.
Formal reviews will ensure the mandate evolves with technological and market advancements, with the first review scheduled for 2030.