DOE updates 45ZCF-GREET model for clean fuel tax credit calculations

The U.S. Department of Energy released an updated 45ZCF-GREET model on June 12, 2026, which biofuel producers use to calculate carbon intensity scores for the 45Z clean fuel production credit. The update removes indirect land use change penalties, adjusts feedstock sourcing rules to exclude non-North American sources, and adds new pathways for renewable natural gas, renewable diesel, and sustainable aviation fuel. It also reflects changes from the One Big Beautiful Bill Act signed in July 2025. The updated model provides more certainty for the renewable fuel industry, though producers still await final feedstock guidance from the USDA and final 45Z regulations from the Treasury and IRS. Industry groups like Growth Energy, Clean Fuels Alliance America, and the Renewable Fuels Association praised the update for helping taxpayers claim the full value of the credit in the current tax year. The model is available on the DOE website.