“Provided we all want a growing and sustainable aviation industry, at some point there won’t be enough biomass and you’ll have to go to eSAF,” Barrett said.
That’s also a concern for Henderson, who mentioned “issues around biodiversity loss, deforestation [and] land-use change that can come from crops” that are used to produce SAF. “On the used cooking oil side,” he added, “there’s a greater and greater risk of fraud in the system, as there’s greater and greater demand.”
That’s why the U.K. is already focusing on “second- and third-generation technologies” such as eSAF.
On the other side of the ocean there’s little interest in exploring alternatives to waste and crops to produce SAF, in part due to worries that eSAF production isn’t a sensible use of renewable energy.
Anna Oldani, chief scientific and technical adviser with the U.S. Federal Aviation Administration, noted that “displacing the renewable electricity to make a low-carbon liquid fuel, versus just using that renewable electricity to decarbonize the grid,” will exact a “severe penalty” in terms of sustainability.
“You’re going to have three times the carbon reduction benefit if you actually just decarbonize the grid, and use [renewable energy] as electricity, rather than diverting it to create a liquid fuel that then gets burned,” she said at Farnborough.
Oldani did add, however, that SAF produced from renewables could be a solution in countries that have an excess of renewable electricity.
