Both SAF’s availability and costs, however, are on a positive trajectory, at least for HEFA (hydrotreated esters and fatty acids), after substantial market developments in 2024. The Forum’s 2025 white paper Financing Sustainable Aviation Fuels: Case Studies and Implications for Investment highlights that production capacity is expected to have reached 4.4 million tonnes per year (Mt/a) in 2024, doubling 2023’s capacity.5 Even so, demand is expected to outstrip supply by 2030. The price premium of SAF has also been reducing throughout 2024, at least in Europe, where the average cost differential between HEFA and conventional jet fuel has fallen from approximately 2x in September 2023 to 1.2x in November 2024.6 Where balance sheets allow it, some airlines are signing long-term contracts for SAF offtakes or taking an equity stake in developing SAF projects, demonstrating a willingness to invest and pay the SAF premium. FIGURE 5 Number, volumes and tenor of SAF offtake agreements, tracked by ICAO ICAO SAF tracker for offtake agreements Number (#) of offtake agreements; offtake volumes (million litres); and length (years) 051015202530354045 02,0004,0006,0008,00010,00012,000 2019 2020 2021 2022 2023 202414,00016,00018,00020,00022,000Offtake volumes (million litres) Offtake agreements (#) Offtake length (years)975 6.3 6.7 6.8 5.9 5.2 4.545 4162343 28 209,21711,755 1,56821,715 Number of agreements Offtake length (years) Offtake volumes (million litres) Source: ICAO.Availability and cost of SAF Executives highlighted the availability and cost of SAF as the biggest challenge affecting progress on decarbonizing aviation during 2025. Many airlines typically highlight SAF’s availability and price as the key obstacles preventing them from signing firm, long-term offtake agreements; equally, investors view such offtake agreements as a “must have” before providing SAF plants with the capital they need to develop. The challenge is that the airline business is known for its small margins – and the COVID-19 pandemic resulted in significant losses and bankruptcy risks that threatened the growth of the sector and exacerbated its traditionally low creditworthiness. ICAO offers an online tracker of SAF offtake agreements, which shows that the number of agreements, as well as their volume and average tenor, has been reducing since they peaked in 2022 (see Figure 5).4 While data should be interpreted cautiously, as offtake agreements are usually multi-year and thus may not need re-signing on a yearly basis, there is a clear downward trend in the willingness to enter long-term deals. This is particularly true in emerging aviation markets looking to grow, such as Asia Pacific, the Middle East and Latin America, where carriers fear the higher ticket prices could have a big impact on competitiveness at a key growth moment. 2.1 Technology challenges ICAO’s online tracker of SAF offtake agreements shows that the number of agreements, as well as their volume and average tenor, has been reducing since they peaked in 2022. Global Aviation Sustainability Outlook 2025 11