(NAFB.com) – Clean Fuels Alliance America sent a letter to Treasury Secretary Janet Yellen urging the agency to issue guidance, including safe harbors, to the 45Z Clean Fuels Production Credit by September 1. The new producer credit becomes available on January 1, 2025, as the existing blender credit expires. Clean Fuels’ letter emphasizes the difficulties that farmers, producers, and fuel marketers are facing in making the transition without guidance on the rules. “U.S. biodiesel, renewable diesel, and sustainable aviation fuel producers are having difficulties finalizing feedstock contracts, securing capital flows, and meeting project deadlines without knowing the value of the credit,” says Clean Fuels in the letter. “The need for policy certainty is urgent.” Clean Fuels is requesting the Treasury to issue safe harbor provisions allowing taxpayers to rely on existing carbon lifecycle assessments, such as the GREET model, to calculate the 45Z credit until a final rule is in effect.