SECTION 3. ALLOWED

METHODOLOGIES FOR DETERMINING EMISSIONS RATES

.01 CORSIA Program . Emissions rates for SAF transportation fuels are determined under the CORSIA program based on the modeling of the fuel lifecycle, including all stages of fuel and feedstock production through to the end use of the finished fuel, to calculate and reduce greenhouse gas emissions from international aviation. In 2016, ICAO adopted CORSIA, which is set out in Annex 16 - Environmental Protection: Carbon Offsetting and Reduction Scheme for International Aviation ­(CORSIA) (2018), https://elibrary.icao.int/home/ product-details/229739.

Using the CORSIA program, there are two ways of obtaining the lifecycle emissions value of a SAF transportation fuel: (1) CORSIA Default and (2) CORSIA Actual. Additional information about CORSIA Default and CORSIA Actual is available at https://www.icao. int/environmental-protection/CORSIA/ Pages/CORSIA-Eligible-Fuels.aspx .

.02 45ZCF-GREET model . Administration of the § 45Z credit requires a determination of the emissions rates of different types and categories of fuels consistently and accurately, including fuels made from different pathways and primary feedstocks (as provided in the emissions rate table). ANL developed, and the DOE published, the 45ZCF-GREET model to determine emissions rates for the § 45Z credit that also meets three key parameters: (1) user-friendliness and consistency, (2) technical robustness of the pathways represented, and (3) consistency with the other requirements of § 45Z.

The first version of the 45ZCF-GREET model, anticipated to be released on Janu

ary 10, 2025, is available at https://www. energy.gov/eere/greet . The first version of the 45ZCF-GREET model includes the most commonly used types and categories of fuel that are anticipated to meet the eligibility requirements to claim the § 45Z credit. Additional types and categories of fuel may be added in future versions of the 45ZCF-GREET model. See the 45ZCFGREET User Manual ⁵ for additional background.