London Heathrow Raises the Bar on Alternative Aviation Fuels

By Garth Calitz

London Heathrow has decided that if it’s going to save the planet, it may as well do so with a bit of ambition and gusto. The airport has announced a new target for alternative aviation fuels to make up 5.6% of its total fuel mix in 2026, stepping well ahead of the UK government’s sustainable aviation fuel (SAF) mandate of 3.6% for the same year. It also marks a notable jump from Heathrow’s own earlier target of 3% in 2025, proving that even large airports can occasionally change gears without stalling the engine.

The announcement comes as pressure mounts on major global hubs to show that decarbonisation plans are more than just glossy PowerPoint slides and well-meaning mission statements to keep the Doomsday mob happy. While hydrogen and electric airliners remain firmly filed under “exciting, but not arriving at Gate 22 any time soon,” SAF is currently the only practical tool available to cut aviation’s lifecycle carbon emissions using today’s aircraft and infrastructure.

Heathrow estimates that achieving the 5.6% SAF blend in 2026 will cut lifecycle carbon emissions by more than 600,000 tonnes of the "lifegiving gas" in that year alone. To put that into perspective, that’s a lot of carbon not making it into the atmosphere, roughly equivalent to taking a very large number of cars off the road or grounding a small fleet of particularly enthusiastic frequent flyers. Looking further ahead, the airport is targeting SAF usage of at least 11% by 2030, signalling that this is intended to be a steady climb rather than a one-off sustainability headline.

The policy environment is slowly catching up. The UK government’s SAF mandate, introduced in 2025, is designed to stimulate domestic production and give fuel producers the confidence to invest in new facilities. Heathrow’s decision to aim above the mandated level effectively positions the airport as an early adopter and perhaps, a slightly overzealous one. The challenge, of course, is supply. Global SAF production remains limited, and demand from airlines, airports and corporate travel programmes is growing faster than new refineries can be built.

To help bridge the cost gap, Heathrow previously announced £86 million in incentives to encourage airlines to use SAF. While the airport has not confirmed whether additional funding will be made available to support the higher 2026 target, it is clear that good intentions alone will not fill fuel tanks. SAF remains significantly more expensive than conventional jet fuel, and airlines, despite their growing sustainability commitments, are unlikely to embrace it in large volumes unless the economics become less painful.

Matt Gorman, Heathrow’s Director of Sustainability, was keen to underline that SAF is already delivering tangible results. “Sustainable aviation fuel is not a hypothetical concept for the future; it’s already producing real impact in 2026,” he said. Gorman also noted that Heathrow accounted for around 17% of global SAF usage in 2024, an impressive statistic that highlights both the airport’s leadership and the still modest scale of SAF deployment worldwide. When one airport can claim such a large slice of global usage, it suggests the market is growing, but it is still very much in its infancy.

For airlines, Heathrow’s push presents both opportunities and complexities. Access to SAF supports corporate customers with net-zero commitments and helps airlines demonstrate progress on emissions reductions. However, the cost premium remains a persistent headache, particularly in a post-pandemic market still wrestling with rising fuel prices, supply chain challenges and the small matter of keeping balance sheets airborne.

Critics are quick to point out that SAF is no silver bullet for a problem that has yet to be scientifically proven beyond doubt. Lifecycle emissions reductions vary depending on feedstock and production methods and long-term sustainability depends on scaling production without unintended environmental consequences. Even so, most credible pathways to net zero by 2050 assume SAF will do much of the heavy lifting over the next two decades. In that context, Heathrow’s higher target is less a grand gesture and more a practical if demanding step toward turning ambition into measurable "progress".

Whether the SAF supply chain can keep up with Heathrow’s raised ambitions remains to be seen. What is clear is that the airport has decided to move from talking about decarbonisation to actually pouring it into the fuel trucks. For an industry often accused by the environmentalists of moving at cruise speed when it comes to climate action, Heathrow’s latest announcement suggests that, at least on SAF, the throttles are being nudged a little further forward.