Will Sustainable Aviation Fuel Help the Industry Reach its Net-Zero Goals?

Contrary to expectation, the aviation industry accounts for a relatively small share of global carbon emissions. It was responsible for 2 percent of global emissions in 2022. However, the industry is growing exponentially, faster than road, rail or shipping. And flying forms the largest chunk of an individual’s carbon footprint. 

The biggest challenge of the aviation industry is that it is the hardest to decarbonize. “Air transport has always been referred to as a ‘hard-to-abate’ sector due to the fact that we don’t have off-the-shelf solutions for decarbonization,” Haldane Dodd, executive director of Air Transport Action Group, said at the Global Sustainable Aviation Forum during COP28 in Dubai.

Though it comes with challenges, the aviation industry has established that the use of sustainable aviation fuel (SAF) is a viable solution and perhaps the only way to decarbonize the sector without relying on carbon offsets. It is estimated that SAF could cover around 65 percent of the total reduction in emissions needed by the industry to reach net zero in 2050, as called for in the 2015 Paris Agreement. 

What exactly is sustainable aviation fuel?

Sustainable aviation fuel is a liquid fuel used in commercial aviation that reduces carbon dioxide emissions by up to 80 percent. It is produced from a number of sources — referred to as feedstock — that include waste oil and fats, green and municipal waste, and non-food crops. 

The first test flight with biojet fuel, which is extracted from plant or animal sources, was performed by Virgin Atlantic in 2008. More recently, Virgin Atlantic celebrated its first 100 percent SAF flight from London to New York City. Named Flight100, it marked the world’s first 100 percent SAF flight by a commercial airline across the Atlantic. The sustainable aviation fuel used for the flight was made from a blend of waste fats and plant sugars.

The industry is ready to use sustainable aviation fuel, but there is not enough of it

Although many airlines are ready to use sustainable aviation fuel to fulfill their net-zero goals, the supply is limited. 

“There was at least triple the amount of SAF in the market in 2022 than in 2021. And airlines used every drop, even at very high prices!” Willie Walsh, the International Air Transport Association’s director general, told India-based aviation magazine SP’s Airbuz. "If more was available, it would have been purchased." In 2023, the amount of SAF available met just 0.20 percent of the industry’s fuel needs. That amount cost around $1 billion. 

During the International Civil Aviation Organization Conference on Aviation and Alternative Fuels, held in Dubai before COP28, 50 airlines representing over 40 percent of global air traffic committed to using SAF for more than 5 percent of their total fuel use by 2030. Many set a goal of 10 percent and some up to 30 percent by 2030.

Boeing is mobilizing its supply chain to complete the testing necessary to ensure its commercial airplanes are 100 percent SAF-compatible by 2030. Since 2022, the company has agreed to purchase 7.6 million gallons of sustainable aviation fuel for its U.S. commercial airplane operations.

Rolls-Royce recently announced that it successfully completed compatibility testing of 100 percent SAF on all of its in-production civil aircraft engine types. This fulfills its 2021 commitment to demonstrate that there are no engine technology barriers to using 100 percent SAF.

How much sustainable aviation fuel is needed, and how much will it cost?

Meeting the 2050 net-zero goals will require an annual production capacity of 118.6 billion gallons of SAF. Investments are in place to expand the annual production from the current 33 million gallons to 1.3 billion by 2025. 

To match the amount of jet fuel the U.S. used in 2019, for example, the country would need to invest $400 billion to deploy 250 sustainable aviation fuel refineries by 2050. 

The current amount of SAF available on the global market is extremely low. And right now, SAF is three to five times more expensive than fossil fuels. Widespread use of the fuel will only be possible if its supply volumes and availability increase significantly as quickly as possible and SAF prices fall. 

Scaling up production is a challenge

The only way SAF is currently produced at scale is with feedstock, but the available supply of feedstock materials is expected to limit increased production, said Agnes Thornton, director and co-founder of Sustainable Flight Solutions Ireland, an independent organization bringing together the aviation industry, supply chain stakeholders, and academia to drive the production and implementation of SAF.

“The development and acceleration of synthetic fuel production, as well as novel feedstock opportunities in the biomass sector, are essential to meet mandated demand from airlines, as well as voluntary demand from other industries,” Thornton said. 

SAF can be produced synthetically via a process that captures carbon directly from the air. It is considered sustainable because the raw feedstock does not compete with food crops or water supplies, and it is not responsible for forest degradation. 

Power-to-X technology is another way to scale sustainable aviation fuel production, Thornton said. Power-to-X is a collective term for technologies that turn electricity into carbon-neutral synthetic fuels, such as hydrogen, synthetic natural gas, liquid fuels or chemicals.

The Lufthansa Group, one of the five largest SAF customers worldwide, is investing up to $250 million in procuring next-generation SAF technologies for the coming years. Their focus is on Power-to-Liquid and Sun-to-Liquid technologies. For example, Lufthansa Airlines, the German Aerospace Center, Airbus, MTU Aero Engines and Munich Airport recently signed a letter stating their intent to research Power-to-Liquid aviation fuels. Furthermore, the Lufthansa Group’s Swiss International Air Lines invested in the solar power manufacturer Synhelion at the end of 2022. The airline aims to fly with the first quantities of solar fuel.

“New technologies are being developed at a fast rate,” Thornton said. “Feasibility is one thing, however more important is sustainability. Several certification bodies, such as the [International Sustainability and Carbon Certification] and RSB, ensure entire supply chain certification and sustainability of the end product. The testing for feasibility and commercialization is yet to come for several of these technologies.” 

To achieve net zero by 2050, increased funding for early-stage research and development, as well as policy development to aid SAF deployment processes, will be the determining factor in how fast the industry will move.