Late last year, Vancouver-based aviation analyst Mark Miller bought airplane tickets to bring his family of four to Rome this summer. The Millers would spend Italy’s high season trawling the city’s ancient ruins, exploring the Vatican, and swooping down to Sardinia to experience the island’s dramatic sea cliffs, white sand beaches, and ancient limestone caves.
Five months later, Miller, a commentator for CBC News, watched in disbelief as Iran closed the Strait of Hormuz—a crucial waterway between the Persian Gulf and the Gulf of Oman, through which nearly 20 percent of the world’s oil supply flows.
The unprecedented closure sent global stockpiles of jet fuel plunging, depleting strategic reserves in the UK, Germany, and France. “Reports out of Europe said that the fuel supply could run low by end of June, which was about the time we would have been there,” Miller says. “The last thing we wanted to do is get stuck in Europe.”
The supply shortage has spread to the US as the war in Iran continues. On Thursday, an American Airlines spokesperson told USA Today that it would temporarily suspend several domestic routes in August and September due to rising jet fuel prices.
In the end, the Millers canceled their trip, alongside millions of summer travelers performing the same mental calculus. With carriers canceling thousands of flights in advance of potential fuel shortages, Miller and other analysts have turned their attention to sustainable aviation fuel, commonly called SAF, which can cut emissions by up to 80 percent but costs two to five times the price of regular jet fuel. United Airlines, Delta, American, and Cathay Pacific are among the carriers now using SAF.
“Right now, conventional jet fuel looks to be twice as expensive going into the summer travel season,” says Lauren Riley, chief sustainability officer for United Airlines. “That makes SAF look like a more competitive alternative financially. In fact, it’s the closest to parity we’ve ever seen. This is the first time in my career that we’re actually having conversations about it.”
Before the blockade, the summer of 2026 was shaping up to be a post-Covid comeback for commercial aviation. With the FIFA World Cup, America’s semiquincentennial celebrations, and Harry Styles’ “Together, Together” world tour on tap, demand for summer travel had never been stronger, Riley says.
With rising prices and increased demand, the airline industry is hopeful that SAF can help bridge the gap. Made from renewable resources like used cooking oil and leftover french fry grease, SAF can be blended with conventional jet fuel as a substitute without any need to alter the aircraft’s design.
US conglomerate World Energy began converting agricultural waste, fats, oils, and greases into SAF at its production facility in Paramount, California in 2016, becoming the fuel’s first commercial-scale producer. “There’s hardly any difference downstream of the treatment process and the blending process,” says Joseph Ran, vice president of asset optimization for World Energy. “You just add an additional blending step of mixing the SAF and the fossil fuel.”
The technology is simple, according to Ran. The problem is creating a reliable supply. Bottlenecks such as scarcity of raw materials called feedstocks, complex infrastructure, and expensive production processes have kept the industry’s use of SAF below 1 percent of total global jet fuel consumption. World Energy, which supplied SAF to United Airlines, Air France, KLM, and others ended SAF production last year “as part of an overall effort to better focus company resources,” according to a company spokesperson.
But this year’s oil crisis has highlighted the need for an alternative to jet fuel. “The closing of the strait has been a very vivid example of overreliance on a single commodity,” says Scott Lewis, president of World Energy’s Net-Zero Services group. In April, United formed a consortium with Microsoft, DSV, and Houston-based multinational energy company Phillips 66 to scale production and unlock 11 million gallons of SAF.