How can sustainable aviation fuel (SAF) future-proof aviation?

The aviation industry is responsible for roughly two-to-three percent of global carbon emissions, with these numbers projected to grow.

SAF provides a compelling solution, offering the potential to reduce lifecycle emissions by up to 65 percent compared to conventional jet fuel, depending on the pathways and feedstocks used. Other technological advancements, such as electric or hydrogen-powered planes, remain far from scalable, especially for long-haul flights. SAF, however, is ready to make an immediate impact on the industry’s decarbonisation efforts.

Regulatory pressures are also driving the push towards SAF adoption. Governments, particularly within the European Union (EU) and the United States, have introduced mandates and incentives to accelerate SAF production and uptake. For example, the EU has imposed SAF usage quotas at airports and introduced subsidies to make SAF more economically competitive.

SAF can be produced through multiple processes, but the most commonly used pathway globally is via the HEFA (Hydroprocessed Esters and Fatty Acids) process. This method converts renewable feedstocks like used cooking oil, animal fats and vegetable oils into jet fuel. HEFA's primary advantage lies in its maturity as a technology and its relatively low production costs.

Other advanced production technologies include:

• Gasification and Fischer-Tropsch (FT), which converts agricultural residues, forestry by-products and municipal solid waste into aviation fuel.
• Alcohol-to-jet (ATJ), which utilises ethanol or other alcohols as feedstocks to produce SAF.
• e-SAF, which utilises CO2 and H2O combined with an input to convert the carbon and hydrogen into jet fuel.

These advanced technologies offer greater feedstock flexibility and include options such as agricultural waste, woody biomass or even carbon captured directly from the air. However, they are still in the early stages of development and come with higher production costs compared to HEFA. Additionally, e-SAF pathways are heavily reliant on a source of very low cost, low carbon intensity energy.

SAF offers several key benefits that make it a promising solution for decarbonising the aviation industry. One of its most significant advantages is its immediate impact. SAF can be used in existing aircraft without requiring any modifications, providing a ready-to-use solution to reduce carbon emissions.

SAF boasts feedstock versatility, as it can be produced from a wide range of renewable sources, many of which are waste products. This creates environmental benefits while reducing reliance on fossil fuels. With the demand for renewable feedstock increasing, SAF production can also create economic opportunities by driving growth in agricultural supply chains and rural economies. It ultimately encourages global collaboration, allowing countries to position themselves as key players in the emerging SAF market by leveraging local resources to produce and export the fuel.

Despite these benefits, SAF faces several challenges. One of the primary obstacles is its high production cost, which is currently two-to-seven times higher than conventional jet fuel. This poses a pricing challenge for airlines and consumers. Sourcing reliable and sustainable feedstocks, such as used cooking oil or forestry residues, remains difficult, particularly when scaled to meet global demand.

A patchwork of regulation also presents significant obstacles. While areas like the EU and the US have clear policies to promote SAF, others, including Australia, have limited regulatory support. Without mandates or incentives, scaling SAF production becomes significantly harder. Overcoming these hurdles will be critical to helping SAF fulfill its potential as a sustainable solution for aviation.

The path forward for SAF includes developing long-term supply agreements, expanding regulatory support and improving technology to lower production costs.

SAF represents a crucial lever in reducing the aviation industry’s carbon emissions. While challenges around cost and scalability persist, global efforts to advance SAF production and adoption are driving the industry toward a more sustainable future. Countries, industries and organisations that invest in SAF today will shape the trajectory of aviation’s tomorrow.