National Corn Growers Association President Tom Hagg and the leaders of 16 state corn grower groups on Sept. 7 sent a letter to Treasury Secretary Janet Yellen advocating for the adoption of the U.S. Department of Energy’s GREET model to measure greenhouse gas (GHG) reductions for the purposes of the sustainable aviation fuel (SAF) tax credit. 

The SAF tax credit, created by the Inflation Reduction Act, includes language specifying that the GHG reduction of the fuel is to be calculated with “the most recent Carbon Offsetting and Reduction Scheme for International Aviation which has been adopted by the International Civil Aviation Organization” or a similar methodology. Representatives of the U.S. biofuel and agricultural industries have been urging Treasury to adopt GREET as a methodology to calculate GHG emissions reductions for the purposes of the SAF tax credit, noting it most accurately reflects current U.S. agricultural practices.

“Because biomass feedstocks, including feedstocks from agriculture and corn ethanol, are essential SAF sources, it is imperative that this new tax credit properly accounts for the lifecycle carbon emission reductions of these sources and the conventional jet fuel these new fuels will replace,” Hagg and his colleagues wrote. “There are numerous reasons as to why the GREET model is the instrument for accomplishing that objective.

“GREET is the federal government’s most robust and updated model or methodology for transportation lifecycle assessment. It is used globally to measure lifecycle greenhouse gas emissions from transportation, and the DOE has the best resources, expertise, and current ability within federal government agencies to assess lifecycle emissions accurately and scientifically. 

“The GREET model accurately accounts for on-farm carbon reduction activities and feedstock yield increases and the improved agriculture production practices that farmers have adopted over the last twenty years,” they continued. “This further solidifies GREET as the methodology the U.S. Department of the Treasury and the IRS should use to determine tax credits for SAF under the IRA.”

A full copy of the letter is available on the NCGA website.