On May 30, 2025, the U.S. Department of Energy (DOE) Bioenergy Technologies Office (BETO) announced that it “removed barriers to domestic bioenergy production by updating its 45ZCF-GREET modeling tool to account for new feedstocks and methods of production, including ethanol from corn wet-milling and natural gas from coal-mine methane.” According to BETO, these measures will allow a wider range of farmers and companies to do business in the alternative fuels market. BETO notes that the U.S. Department of the Treasury adopted the 45ZCF-GREET model to help transportation fuel producers assess their eligibility for 45Z, also known as the Clean Fuel Production Credit, a provision in the Internal Revenue Code that provides tax credits for the production of certain clean transportation fuels. The latest GREET^® (Greenhouse gases, Regulated Emissions, and Energy use in Technologies) model, updated user manual, and a log of all changes are available online. For questions on how to use the model, contact 45ZCFGREETSupport@ee.doe.gov.