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Produced from diverse sources such as used cooking oil, sewage, household rubbish, or even CO2 itself, SAF can reduce CO2 emissions by up to 80% compared to conventional fuel, according to the International Air Transport Association (IATA). And it can be used without modifying engines.
Companies including Rolls-Royce and Airbus have used 100% SAF to power engines during test flights, but it is already seeing much wider use when mixed with conventional fuel. According to the IATA, it has been used on more than 370,000 flights since 2016. The organisation forecast production of 100m litres in 2021, and that number is set to skyrocket as demand increases rapidly, with forward purchase agreements accounting for 14bn litres of future supply.
Sustainable specialism
With net-zero targets drawing ever closer, the UK government sees SAF as a potentially major contributor in the race to reduce aerospace emissions. Last July it launched a consultation on a SAF mandate, which would require jet fuel suppliers to blend increasing proportions of SAF into aviation fuel from 2025, and last November the Prime Minister and Bill Gates announced £400m of public-private investment in clean technologies such as SAF.
Production in the UK could generate £0.7-1.66bn each year, claims the government, creating 11,000 green jobs by 2040. Sustainable Aviation, which counts Rolls-Royce, Airbus and British Airways among its members, hopes that up to 12 plants could be built by 2030, reducing UK aviation emissions by up to 24% by 2050.
British Airways will become the first airline to use SAF produced in the UK, after signing a multi-year agreement with Phillips 66 Ltd. The SAF will be produced at scale for the first time in the UK at the firm’s Humber refinery. The airline said it would purchase enough sustainable fuel to reduce lifecycle CO2 emissions by almost 100,000 tonnes, the equivalent of powering 700 net-zero CO2 emission flights between London and New York on its fuel-efficient Boeing 787 aircraft.
The companies aim to grow production capacity and to use a wider range of sustainable waste feedstocks in future, said British Airways chief executive Sean Doyle. “The development of SAF is a major focus for us, and forms part of our commitment to achieving net-zero carbon emissions by 2050 through a series of short-, medium- and long-term initiatives.”
Stepping stone
Despite the interest at national and international level, it is not exactly clear how sustainable SAF can truly be. If made from biomass – as suggested by the US Department of Energy – it will bring the inevitable concerns about land and water use that accompany any biofuel project.
Perhaps more concerning for airlines is the cost – according to a 2021 Aviation Today article, SAF costs four times as much to produce as conventional jet fuel.
Some organisations, such as the Aerospace Technology Institute, see SAF as a short-term stepping stone on the route to true net-zero aviation, with hydrogen seen as the most promising future option.
With time running out to cut emissions, potential solutions cannot be ignored, no matter how short term their use might end up being. And with operators facing steep bills to upgrade aircraft, SAF might stick around for longer than expected.
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