Sustainable Aviation Fuel (SAF): When Will Flights Actually Become Carbon Neutral?

The aviation industry accounts for roughly 2.5% of global carbon dioxide emissions. As climate concerns grow among travelers, major airlines are pointing to Sustainable Aviation Fuel (SAF) as the ultimate fix. However, switching a global fleet from fossil fuels to biofuels is not a simple flip of a switch.

What Is Sustainable Aviation Fuel?

SAF is a liquid fuel designed to reduce lifecycle carbon emissions by up to 80% compared to traditional jet fuel. Unlike conventional aviation fuel, which is extracted and refined from crude oil, SAF is produced from renewable resources.

Today, the most common type of SAF is made using a process called HEFA (Hydroprocessed Esters and Fatty Acids). This involves refining used cooking oil, animal fats, and agricultural waste into jet fuel. Companies like Neste and World Energy are currently the largest commercial producers of this fuel globally.

In the future, the aviation industry hopes to rely heavily on synthetic e-fuels. These advanced fuels are created by capturing carbon directly from the air and combining it with green hydrogen. While e-fuels are incredibly promising because they do not rely on limited agricultural waste, they are currently produced in very small, experimental batches.

The Current Reality of Biofuels in Aviation

Despite heavy marketing campaigns from airlines, SAF is barely making a dent in global fuel consumption right now. In 2023, the International Air Transport Association (IATA) reported that SAF accounted for just 0.2% of the world’s commercial aviation fuel. This means 99.8% of commercial flights are still burning fossil fuels.

However, specific airlines are making significant purchases to kickstart the market. United Airlines has been a massive proponent of the technology, securing agreements to buy over 3 billion gallons of SAF over the coming decades. Delta Air Lines has also committed to using 10% SAF by the end of 2030.

Because SAF is not currently available at every airport, airlines often use a “book and claim” system. An airline might buy a batch of SAF that gets loaded into a random plane in Los Angeles, but the airline will claim the environmental carbon credit for a flight departing from New York.

Timelines for Carbon-Neutral Flights

When will you actually fly on a fully carbon-neutral airline? The global aviation industry has set a strict target of achieving net-zero carbon emissions by 2050. This timeline relies heavily on SAF replacing at least 65% of conventional jet fuel.

To force the industry to adapt, governments are stepping in with strict mandates. The European Union recently passed the ReFuelEU aviation rules. Under this law, aviation fuel suppliers must ensure that 2% of fuel made available at EU airports is SAF starting in 2025. This requirement jumps to 6% in 2030, 20% in 2035, and a massive 70% by 2050.

The United States is taking a slightly different approach. Instead of strict mandates, the US government created the SAF Grand Challenge. This initiative aims to produce 3 billion gallons of SAF domestically by 2030 and 35 billion gallons by 2050.

The High Cost of Greener Travel

The biggest roadblock to carbon-neutral flights is the price tag. Conventional jet fuel usually costs between $2.50 and $3.00 per gallon. Right now, SAF is two to four times more expensive than traditional fuel. Airlines operate on very tight profit margins, meaning they cannot simply absorb this massive cost increase without raising ticket prices for passengers.

To help close this price gap, governments are offering financial incentives to producers. The US Inflation Reduction Act includes a tax credit specifically for SAF production. Depending on exactly how much the specific batch of fuel reduces greenhouse gas emissions, producers can claim a tax credit between $1.25 and $1.75 per gallon. While this financial support helps, it is not enough to make SAF cheaper than fossil fuels today.

Challenges in Scaling Production

Beyond the high cost, the industry faces a severe shortage of raw materials. There is simply not enough used cooking oil and leftover animal fat in the world to power the global aviation fleet.

To scale up production, energy companies need to build entirely new refineries that can process solid municipal waste, woody biomass, and eventually synthetic e-fuels. IATA estimates that the industry will need roughly $1.45 trillion in capital investments to build the infrastructure required to hit the 2050 net-zero goals.

Furthermore, current commercial aircraft are only legally certified to fly on a maximum 50% blend of SAF and traditional jet fuel. While engineering tests prove that modern jet engines can handle higher blends, regulatory hurdles remain. In November 2023, Virgin Atlantic successfully flew a Boeing 787 from London to New York using 100% SAF. This historic test flight (dubbed Flight100) proved the technology is safe and effective. Now, the challenge is building enough fuel to make flights like that a daily reality.

Frequently Asked Questions

What is Sustainable Aviation Fuel made from? Currently, most commercial SAF is made from renewable waste products. This includes used cooking oil from restaurants, tallow (animal fat), and agricultural residues. Future versions of the fuel will be made from municipal solid waste and carbon captured directly from the atmosphere.

Will ticket prices increase to pay for SAF? Yes, it is highly likely that ticket prices will rise as airlines transition to SAF. Because sustainable fuel costs two to four times more than standard jet fuel, airlines will need to pass at least some of those costs onto passengers to maintain profitability.

Can existing airplanes fly on biofuels? Yes. SAF is considered a “drop-in” fuel. This means it has the same chemical properties as traditional jet fuel and can be pumped directly into existing aircraft engines without any mechanical modifications. Currently, commercial regulations limit airlines to a 50% blend, but engines are mechanically capable of burning 100% SAF.