A bipartisan group of 21 federal lawmakers on July 28 sent a letter to U.S. Treasury Secretary Janet Yellen urging the Treasury Department to adopt the U.S. Department of Energy’s GREET model as the secondary methodology for calculating the sustainable aviation fuel (SAF) tax credit.

According to the lawmakers, adoption of the GREET model would “dramatically enhance the effectiveness of existing [SAF] incentives and accelerate the aviation industry’s decarbonization efforts.”

“Barring the aviation industry from embracing the most accessible SAF options will not only deprive American farmers of the chance to contribute to a new clean energy market, but also severely delay adoption of promising low-emission energy sources,” the lawmakers wrote in the letter. “This missed opportunity will result in the continued release of millions of tons of carbon emissions in the years ahead that could otherwise be abated.”

The letter stresses that GREET “indisputably mirrors the criteria required by statute for a secondary methodology” and “offers the ability for SAF stakeholders to adopt emerging advancements and technological breakthroughs.” The lawmakers also note that adoption of the GREEET model “ensures that every participant involved in the SAF lifecycle has the opportunity to effectively engage in carbon-reducing practices.”

Within the letter, the highlights five specific justifications for the use of GREET. First, it is a “similar methodology,” as required by statute, to “the most recent Carbon Offsetting and Reduction Scheme for International Aviation (CORSIA), which has been adopted by the International Civil Aviation Organization (ICAO).” Second, GREET satisfies the criteria for lifecycle analysis under the Renewable Fuel Standard. Third, the lawmakers stress that the use of GREET is mandated under statute to calculate the lifecycle analysis (LCA) for other transportation fuels, including hydrogen and non-aviation fuels under the Clean Fuel Production Tax Credit. The letter specifically stresses that some facilities will produce both aviation and non-aviation fuels. Requiring those facilities to utilize different models for aviation and non-aviation fuels would unnecessarily complicate the ability of those taxpayers to calculate credit values for those fuels, according to the letter. Fourth, using GREET for LCA creates a system to reward farmers for climate-smart agriculture practices and introduces a market-driven approach to sustainability. Finally, GREET is the most up-to-date, accurate model for our domestic practices, the lawmakers said.

“It is of utmost importance that Treasury adopts GREET as the secondary model for SAF provisions outlined in IRC Section 40B,” the lawmakers wrote. “Failure to do so would impede the majority of the existing SAF market from capitalizing on this incentive, hinder our nation’s ability to make additional investments in this technology, and obstruct progress in carbon reduction efforts. We strongly urge Treasury to take the necessary steps to implement GREET as the secondary model without delay.”

The letter is signed by Reps. Mark Pocan, D-Wisc.; Angie Craig, D-Minn.; Ashley Hinson, R-Iowa; Max Miller, R-Ohio; Mariannette Miller-Meeks, R-Iowa; Nikki Budzinski, D-Ill.; Eric Sorensen, D-Ill.; Mike Flood, R-Neb.; Brad Finstad, R-Minn.; Mark Alford, R-Mo.; Mike Bos, R-Ill.t; Darin LaHood, R-Ill.; Frandy Feenstra, R-Iowa; Zach Nunn, R-Iowa; David Scott, D-Ga.; Adrian Smith, R-Neb.; Dusty Johnson, R-S.D.; Pete Stauber, R-Minn.; James Baird, R-Ind.; Kim Schrier, D-Wash.; and Don Bacon, R-Neb.

Growth Energy has welcomed the letter, stressing that it demonstrates the importance of Treasury’s adoption of the GREET model for the SAF tax credit. “GREET is the best lifecycle analysis model to fully and accurately capture the full carbon emissions benefits of American-made, farm-based feedstocks for SAF,” said Emily Skor, CEO of Growth Energy. “Not adopting this model would rob many American farmers and their communities of the chance to participate in this new clean energy market as it takes off. SAF represents an enormous opportunity to significantly lower carbon emissions in the aviation sector while simultaneously growing the rural economy. We thank Reps. Pocan, Hinson, Craig and all the other signatories in the House for sending this letter, and for doing their part to make sure Treasury gets this right.”  

A full copy of the letter is available on Growth Energy’s website.