As the U.S. Treasury and IRS write rules for the new Clean Fuel Producer and SAF credits, it is vital that they maintain key provisions. The new tax rules must continue to exclude from eligibility fuels made by co-processing fats and oils with non-biomass feedstocks. Treasury must also allow U.S. producers to use domestically grown crops for fuel production; The Greenhouse Gases, Regulated Emissions, and Energy Use in Transportation (GREET) model from Argonne National Labs is the most up-to-date model and should be the gold standard for measuring lifecycle GHG emissions.

Congress determined more than a decade ago that making co-processed diesel at a conventional oil refinery does not generate the same economic, environmental and societal benefits as producing renewable diesel at a stand-alone, greenfield facility. Congress clarified in the new tax credit law that co-processed fuels – including SAF – are ineligible for incentives. The Treasury must follow Congress' intent.

While Congress specified the GREET model for measuring GHG emissions from transportation fuels, it also specified the ICAO model for SAF. The ICAO model contains outdated assumptions about the indirect emissions associated with U.S. crops that could unfairly exclude them from eligibility for tax credits. The GREET model is updated regularly. Treasury should specifically acknowledge the GREET model as a comparable substitute in final tax guidance.

Please ask your Representative and Senators to urge the IRS to follow congressional intent by  excluding co-processing and supporting homegrown fuels.