SAF represents aviation's most promising and practical path to reducing carbon emissions and achieving 2050 sustainability goals. In May 2025, the UK Government introduced the Sustainable Aviation Fuel Bill (SAF), which has reached Report Stage in Parliament. The Chartered Institute of Logistics and Transport (CILT UK) is helping the Government with advice and guidance on SAF and how it can help the logistics and transport sector. 

But understanding SAF 's workings and benefits is crucial for the aviation sector – and why it must be embraced sooner rather than later. Geoff Maynard, member of the Aviation Policy Group at CILT (UK), recently gave evidence in Parliament to the Sustainable Aviation Fuel Bill Committee as MPs further consider the Bill.

Geoff Maynard has worked in the aviation sector for over 25 years, undertaking a wide range of aviation related commissions, many with extensive environmental content. Educated at Queens’ College, Cambridge, with a degree in Natural Sciences, Geoff has held senior positions in both the private and public sectors. He has worked on many major projects including Heathrow’s T5, the Olympic Terminal in Beijing, and a new airport for Eswatini.

Geoff gives his expert insight into SAF, its benefits, challenges, future and why the sector must embrace it. 

SAF is a cleaner alternative to traditional jet fuel that can power aircraft without engine or infrastructure changes. Produced from sustainable resources like agricultural waste, used cooking oil, and municipal solid waste, SAF is a "drop-in" fuel that can be used in existing aircraft engines and fuel systems without modifications. It performs identically to traditional jet fuel in terms of energy density, freezing point, and combustion characteristics, requiring no special training or new equipment. SAF can also be produced using green electricity, water and carbon dioxide extracted from the air. This SAF, also known as e-fuel, could be produced in very large quantities – constrained only by the investment in new plant.

Raw materials undergo treatments to remove impurities, then hydro processing, gasification, or fermentation are used to transform them into high-quality aviation fuel that mimics traditional jet fuel properties. The aim for the government is to blend SAF fuel with traditional fossil jet fuel and with time increase the SAF fuel ratio and thus lower the use of fossil jet fuel. 

Sustainable Aviation Fuel (SAF) offers significant environmental advantages, primarily through a substantial reduction in lifecycle carbon emissions. Unlike traditional jet fuel, which releases ancient carbon into the atmosphere, SAF is derived from materials that recently absorbed atmospheric carbon dioxide, creating a closed carbon loop. This process can lead to lifecycle carbon emission reductions of up to 80% compared to conventional fossil jet fuel.

Additionally, SAF contributes to waste reduction by repurposing materials such as used cooking oil, agricultural residues, and municipal waste into energy, fostering a circular economy in waste management and energy production.

The government is encouraging this trend by first, mandating the percentage of SAF that must be included in aviation jet fuel sold in the UK. Second the SAF bill currently going through parliament establishes a company that can contract with industry to produce SAF at an agreed cost. If the SAF is ultimately sold at a price more than the agreed cost the excess is returned to the Government. Conversely if the SAF is sold at less than the agreed cost, the Government reimburses the producer for the loss. In this way, the Government eliminates the uncertainty that private industry faces in producing SAF, ensuring they cover their costs but also ensuring sufficient SAF is available to meet the mandated percentage.

These measures will help SAF overcome its adoption barriers, primarily its high cost, which is two to five times greater than traditional jet fuel, impacting airline profitability and passenger pricing. The Government expects that as the mandated SAF percentage rises, volumes produced will rise and it will naturally bring the price down as demand goes up.

The development of SAF is creating new industries and economic opportunities, with companies investing in production facilities, research, and supply chains. This investment is generating jobs. For airlines, SAF is vital for achieving sustainability goals and meeting passenger demands for eco-friendly travel. The ability to hit sustainability targets by simply adding a fuel the mix is the biggest pull factor, but for this to happen Government must encourage and support the development and introduction of SAF.  This year all jet fuel sold in the UK must  by law contain 2% SAF, with the percentage rising linearly to 10% by 2030, and on to 22% by 2040.

The future of SAF looks promising due to advancements in technology and increased production. Researchers are creating new methods that lower costs and reduce environmental effects. Major airlines aim for net-zero, which means SAF will play a vital role. Aircraft are being designed for 100% SAF, and production capacity is set to grow. 

The availability of fossil jet fuel will reduce as other sectors, notably road transport, move away from fossil diesel and petrol. SAF will fill this gap and with the support of CILT UK we are helping bridge the conversation between our industries, airlines and Government.