Headline: United Airlines just became the first airline in history to operate a passenger flight using 100% sustainable aviation fuel

Sustainable Aviation Fuel (SAF) is one of the next big things in energy. United’s flight was the aviation industry’s first passenger flight using 100% non-petroleum-based SAF. It was Chicago to Washington, has more than 100 passengers including United’s CEO.

More than 4.5 billion people flew in 2019. That created about two percent of global manmade carbon emissions. “While COVID-19 may impact passenger growth trajectories in the medium term, aviation’s annual passenger numbers are still expected to grow towards 7.5 billion by 2035, meaning that effective action on reducing carbon emissions is essential to ensure the sustainable development of the industry,” says the International Air Transport Association (IATA).

The United flight had 500 gallons of SAF in one engine and 500 gallons of traditional fuel in the other. SAF is drop-in ready. It can be used by itself or mixed with regular fuel.

“SAF can start from various feedstock sources, such as oils from plants, algae, greases, fats, waste streams, alcohols, sugars, and captured CO2, but ends up being the same hydrocarbon mixture called kerosene that we know as jet fuel,” says GE Aviation’s engineering leader for aviation fuels and additives. “The use of SAF can lower the lifecycle carbon footprint compared to commercial jet fuel.

Humber was completed in 1968 and is in North Lincolnshire, United Kingdom

Scale is the challenge now – getting enough SAF online. Traditional oil companies are using their expertise in the effort. “The Humber Refinery was the first in the UK to co-process waste oils to produce renewable fuels and now we will be the first to produce SAF at scale,” says Phillips 66 refinery general manager Darren Cunningham. “We’re refining almost half a million liters of sustainable waste feedstocks a day.” Phillips 66 and British Airways have an agreement on fuel supply.

SAF production is limited now, less than 1% of the global jet fuel demand. Industry is hoping for two percent by 2025. These transitions take time. GE Aviation wrote, “The cost is still the challenge, with SAF being considerably more expensive than traditional jet fuels. However, there are mechanisms, incentives, policies, and regulations being put in place that will help SAF use to become more economically viable for the operators.”

SAF proves that the energy transition is happening in many places.