What Is Sustainable Aviation Fuel, and Will It Really Make Flying Greener?

29.04.2024 - 22:45 / afar.com / Airlines

The airline industry is betting big on sustainable aviation fuel, or SAF—a fuel alternative made from renewable biomass and waste products. Dozens of airlines around the globe are experimenting with it; in November, headlines buzzed following the first fully SAF-powered transatlantic flight on a commercial airline (British carrier Virgin Atlantic). But while the emissions-heavy airline sector is heralding SAF as a silver bullet to its decarbonization goals, experts say environmental pitfalls and other obstacles abound.

SAF is a liquid, energy-dense fuel sourced from nonpetroleum sources, known as feedstocks, including renewable plant- and waste-based products such as used cooking oil, municipal waste, and algae. Estimated to slash the carbon footprint of conventional kerosene-based jet fuel by as much as 80 percent, SAF is also attractive for the “drop-in” compatibility it offers with existing airplane technology (meaning that it’s capable of being used with existing aircraft engines and other supply infrastructure and is compatible to be safely mixed with conventional jet fuel).

Currently, SAF is positioned as the sector’s leading means of meeting pressing U.N.-set climate targets and emerging government-imposed mandates that require airlines to partially employ SAF to operate within their borders (now instated in places like the European Union, United Kingdom, and Singapore). The International Air Transport Association (IATA), a global trade association representing some 300 airlines, has committed to meeting a net-zero emissions target by 2050—and SAF is tied to a substantial 65 percent of its calculations for reaching that goal.

Currently, 0.2 percent of aviation fuel consumed worldwide each year is SAF. “SAF use is a drop in the bucket,” says fuel expert Nikita Pavlenko of the nonprofit International Council on Clean Transportation (ICCT).

Why is that? Well, not only is SAF up to five times more expensive than standard jet fuel, but also, it’s scarce: While roughly 158 million gallons were produced in 2023, IATA says that 119 billion gallons of SAF is needed annually to reach net-zero emissions by 2050.

Costs and funding are a big part of the scalability issue. The ICCT website reports that supply is not currently where it needs to be because the funds that “airlines are throwing at SAF today are insufficient to increase supply and build true markets.” Organizations like the ICCT suggest that airlines are unlikely to voluntarily pay a premium on fuel costs since it would increase their operating costs, push airfares up, and potentially quell demand by pricing customers out of flying. Instead, these groups suggest that supply needs to be boosted via SAF government mandates as well as economic