Greener airplane fuel is here, and we’re going to need lots more

Major airlines have committed to eliminating their net carbon emissions by 2050 even as they expect a fivefold increase in annual global passengers over the same period. To meet that ambitious goal, they’ve touted the potential of sustainable aviation fuel, or SAF, a product that is chemically identical to kerosene but more environmentally friendly. Until technologies such as batteries or clean-burning hydrogen are commercially viable for powering large aircraft, which could take decades, SAF is the industry’s best option for getting greener. Yet, for now, the alternative fuel is used only rarely in commercial flights. Its limited adoption is a result of two interconnected challenges: SAF is expensive for airlines to purchase, and production volumes remain constrained. SAF makes up only about 0.1% of the global aviation fuel supply. Some carriers are blending small amounts of it with jet fuel on certain flights. Yet the largest carriers are keen to demonstrate how eager they’ll be as customers if production increases. By year’s end, United plans to fly what it calls the first 100% SAF passenger flight from Chicago to Washington D.C. using a Boeing 737 Max 8. Federal regulators have approved the voyage -- a technical demonstration without paying customers -- to show that the current limit of 50% SAF for a flight can be raised without problems. On Nov. 8, to mark the reopening of the US to vaccinated Europeans, British Airways flew an Airbus A350-1000 from London to New York City on 35% SAF. The carrier said that was the largest amount blended to date on a commercial flight. Widespread use of SAF could represent about 65% of the total cuts needed to meet the airlines’ 2050 emissions targets. But alternate fuels cost about four times more than standard kerosene-based fuel, a gap referred to as the “green premium.” <br/>