UK Aviation’s Sustainable Fuel Ambitions Face Turbulence: Will Mandates Take Flight?
Just 1.6% of UK flights currently use sustainable aviation fuel (SAF), falling 20% short of the government’s 2% mandate for 2025. This shortfall isn’t just a missed target; it’s a stark warning that the path to decarbonizing aviation is far more challenging – and reliant on far more than good intentions – than many believe.
The SAF Supply Bottleneck: Beyond Recycled Cooking Oil
Currently, the UK’s entire supply of sustainable aviation fuel originates from a single source: recycled cooking oil, primarily from Asia. While a step in the right direction, this reliance creates a significant vulnerability. The Department for Transport (DfT) data reveals a mere 160 million litres of SAF were used up to early October, a drop in the ocean compared to the 10 billion litres of conventional jet fuel burned. This dependence on a single feedstock highlights the urgent need for diversification.
The Promise – and Peril – of Second-Generation SAF
The government’s ambitious targets – rising to 10% by 2030 and 22% by 2040 – hinge on the widespread adoption of ‘second-generation’ SAF. These fuels, derived from sources like agricultural waste and algae, are considered more sustainable long-term. However, they are currently unproven at scale and significantly more expensive to produce. Airlines are rightly questioning whether these mandates are achievable without substantial investment and technological breakthroughs.
Government Policy and Industry Incentives: A Mixed Bag
The UK government is attempting to stimulate SAF production through a forthcoming SAF bill, promising “revenue certainty” for investors. Heathrow Airport is also leading the charge, offering airlines reduced landing charges for using cleaner fuels, aiming for a 3% SAF usage rate in 2025. These are positive steps, but they may not be enough.
Aviation Minister Keir Mather has indicated that Heathrow expansion will be tied to climate impact reduction, framing SAF as a key enabler of growth. However, the simultaneous approval of airport expansions – Gatwick and Luton included – raises questions about the government’s overall commitment to curbing aviation emissions. The tension between economic growth and environmental sustainability is palpable.
Global Context: The UK is Ahead, But the World is Lagging
Despite these challenges, the UK is progressing faster than most nations. The International Air Transport Association (Iata) recently warned that global SAF production is stalling, with current levels at just 0.6% of total jet fuel consumption, projected to reach only 0.8% in 2026. Iata’s director general, Willie Walsh, rightly criticizes mandates as potentially counterproductive, arguing for incentive-based approaches that encourage production rather than simply demanding it.
This global stagnation underscores a critical point: SAF isn’t just a UK problem; it’s a global challenge requiring international collaboration and investment. The current reliance on recycled cooking oil isn’t scalable, and alternative feedstocks require significant research and development. The International Energy Agency (IEA) provides detailed analysis on the challenges and opportunities in sustainable aviation fuels.
Power-to-Liquid Fuels: A Potential Game Changer?
Beyond second-generation biofuels, ‘power-to-liquid’ (PtL) fuels offer a potentially transformative solution. These fuels are created by combining captured carbon dioxide with hydrogen produced using renewable energy. While still in the early stages of development, PtL fuels could offer a truly sustainable pathway to decarbonizing aviation. However, the energy intensity and cost of PtL production remain significant hurdles.
The Cost Factor: Making SAF Economically Viable
The fundamental challenge remains cost. SAF is currently several times more expensive than conventional jet fuel. Without substantial government subsidies, technological advancements, and economies of scale, widespread adoption will be impossible. The industry needs a clear, long-term policy framework that incentivizes investment in SAF production and deployment.
Duncan McCourt, CEO of Sustainable Aviation, remains optimistic, stating the UK is using “significant quantities” of SAF and will meet the mandate. However, optimism alone won’t fill the fuel tanks. The current trajectory suggests a significant acceleration in SAF production and a fundamental shift in feedstock sourcing are urgently needed.
What will it take to truly unlock the potential of sustainable aviation fuels? The answer lies in a combination of innovative technologies, supportive government policies, and a willingness from the industry to embrace a future powered by more than just recycled cooking oil. Share your thoughts on the future of SAF in the comments below!
