Explainer: Sustainable Aviation Fuel Gets Off The Ground

Reducing greenhouse gas emissions in aviation, one of the fastest-growing sources of emissions in many parts of the world, is a major challenge. Cross-country and international flights are especially emissions-intensive. And so far, clean substitutes for fossil jet fuel have been very expensive and limited.

Still, governments are beginning to require and incentivize the use of small amounts of sustainable fuels — generally made from plants (biofuels) and used cooking oils or manufactured using renewable energy — alongside fossil fuels. Burning these sustainable fuels in jet engines still produces carbon emissions. But those emissions are balanced by the carbon removed from the atmosphere in the process of making the fuels, either from growing the plants or manufacturing the fuels.

In the U.S., the Environmental Protection Agency’s Renewable Fuel Standard has worked alongside tax incentives and state programs to encourage the construction of production capacity over the past few years. Several of those facilities began kicking into gear late last year and early this year. The two lines in the chart above show that SAF production is suddenly shooting up as new capacity finally comes online.

It is unclear whether some of the policies that have led to SAF’s growth so far will survive efforts by Republicans in Washington to roll back policies that support renewable energy and climate action.

U.S. SAF production capacity increased by 25,000 barrels per day at the end of 2024, from near zero, as facilities in California and Texas came online, according to EIA’s analysis of company announcements and trade press. Production capacity jumped to 30,000 barrels per day by February 2025.

Overall production of “other biofuels,” EIA’s category that includes SAF but excludes the more established biofuels ethanol, biodiesel and renewable biodiesel, is expected to double in 2025 compared to last year, then rise another 20% next year, driven in large part by growing SAF production, the EIA said.

Still, those volumes represent less than 2% of the 1.7 million barrels of jet fuel used in the U.S. each day. Because the aviation sector overall is continuing to grow, the share of sustainable fuels in the overall fuel mix will remain about the same next year even after the additional production growth.