Environmental groups have suggested that new US guidelines for sustainable aviation fuel (SAF) could lead to production of biofuels that may not be sustainable.
At issue are guidelines released on 15 December defining how fuel producers can determine which alternative fuels qualify for a new SAF tax credit.
Environmental groups have been urging the government not to allow a method known as ‘GREET’, which they say fails to fully account for a biofuel’s lifecycle emissions.
“Our initial assessment is that this would be a blank check for fuels made from sugar cane, soybean and rapeseed – none of which are sustainable or consistent with Congress’ intent,” said a spokesman for the Environmental Defense Fund.
A 2022 US law grants fuel producers a $1.25-$1.75 tax credit per gallon for SAF deemed to have 50% less life-cycle carbon emissions than fossil-based jet fuel. The law defines qualifying fuels as those meeting definitions within ICAO’s Carbon Offsetting and Reduction Scheme for International Aviation.
However, the law also allows fuels meeting other “similar” methods as qualifying.
The 15 December guidance, issued by the Internal Revenue Service and US Department the Treasury, starts to define those other methods.
Specifically, the government says current GREET models to not satisfy SAF requirements. However, it is developing a “modified GREET” model for SAF, to be completed in early 2024.
The aviation industry, however, met the new rules with praise:
“Today’s announcement is welcome news for the aviation sector, as it will help to accelerate the production and availability of SAF and stimulate new investment,” said trade group Airlines for America.
It added that the GREET model “ensures that credible and up-to-date life-cycle emissions measurements of a wide range of SAF pathways can be made.”