On Friday, June 12, the Department of Energy released a much-anticipated update to its GREET model, which is used by biofuel producers to calculate the value of the 45Z Clean Fuel Production Tax Credit. Many of these changes were initiated under the “One Big Beautiful Bill” of 2025.

NEFI has included the need for the updated GREET model in its testimony and written comments to the DOE and IRS throughout the past year. The value of 45Z clean fuel production credits is based on a fuel's emissions factors, and these updated emissions profiles, which will now support a diverse range of feedstocks and emerging fuels and technologies, will more accurately determine the credit's value.

GREET stands for Greenhouse gases, Regulated Emissions, and Energy use in Technologies. The updated GREET model has removed the indirect land-use change (ILUC) penalties from the original 45Z calculations, as written into the Biden Inflation Reduction Act.

NEFI continues to press for reinstatement of the Section 40A biodiesel blenders tax credit, which many in our industry continue to view as the more effective vehicle for supporting renewable fuel use in our sector. For more information, contact NEFI Manager of Government Affairs Liam Dotson at liam.dotson@nefi.com.