The Department of Energy’s (DOE) Argonne National Laboratory (Argonne) began developing the GREET® (Greenhouse gases, Regulated Emissions, and Energy use in Technologies) life cycle analysis (LCA) suite of models in 1994, with the first version released in 1995. Life cycle analysis is a framework for assessing the environmental impacts associated with all stages of the supply chain of a technology or product. 

The GREET model was developed to evaluate energy and environmental performance of technologies to assess research, development, and deployment (RD&D) progress, inform RD&D directions, and inform performance goals set by governments, corporations, and other stakeholders. Its development and applications have been an integral part of DOE’s RD&D efforts to pursue energy and material technologies for energy efficiency, affordability, and environmental sustainability.

GREET is a tool that assesses a range of life cycle energy, emissions, and environmental impact challenges and that can be used to guide decision-making, research and development, and regulations related to transportation and the energy sector.

For any given energy and vehicle system, GREET can calculate: 

  • Total energy consumption (non-renewable and renewable) 
  • Fossil fuel energy use (petroleum, natural gas, coal)
  • Greenhouse gas emissions 
  • Air pollutant emissions 
  • Water consumption.

GREET models are developed for specific use cases. Users are responsible for ensuring they have selected the correct model for their intended purpose. For instance, annual releases of R&D GREET are comprehensive in order to inform the life cycle analysis technical community and elicit stakeholder feedback. R&D GREET may not be the version of GREET adopted in independent regulatory programs (e.g., tax credits). Stakeholders seeking a GREET model for purposes of compliance with a given regulatory program should review guidance specific to that program to ascertain the appropriate version of GREET to use.

Click to access specific GREET versions:

The Argonne R&D GREET Model is used to evaluate energy use and emissions output of transportation and energy sector technologies to assess research and development progress and inform RD&D direction.

R&D GREET is available both as a Microsoft Excel file as well as a web-based tool.

DOE is collaborating with other federal agencies to develop the §40B(e)(2) GREET model to calculate the emissions reduction percentages under the Sustainable Aviation Fuel Credit, § 40B(e)(2) of the Inflation Reduction Act. The collaborating agencies anticipate that the § 40B(e)(2) GREET model will be available in early 2024 and will satisfy the statutory requirements of § 40B(e)(2). (Notice 2024-6 (irs.gov)

45VH2-GREET is the model that has been adopted by the U.S. Department of the Treasury to determine emissions rates for purposes of the Clean Hydrogen Production Tax Credit under Title 26 of the U.S. Code, Section 45V.

Download the latest version of the model 45VH2-GREET 2023.

The 45VH2-GREET 2023 user manual describes the methodology used by 45VH2-GREET 2023 to calculate life cycle greenhouse gas (GHG) emissions of hydrogen production under a well-to-gate system boundary and provides instructions on how the model should be used.

Download the 45VH2-GREET 2023 user manual.

Users should ensure that they are running the model on Microsoft Office 365 or Microsoft Office 2021, on a Windows operating system. They should also ensure that the zip file is downloaded to a hard drive on their computer that then virtual drives (e.g. cloud drives).

Download a factsheet of frequently asked questions (FAQs) and corresponding answers about how to use 45VH2-GREET.

If you have questions on how to use 45VH2-GREET, please submit them to 45VH2GREETSupport@ee.doe.gov. DOE will only respond to questions on how to use 45VH2-GREET. Questions about the 45V tax credit and eligibility for the tax credit should be directed to the Internal Revenue Service. DOE will not respond to questions about the 45V tax credit or eligibility for the tax credit.

The CA-GREET4.0 model is a modified version of the Argonne GREET1 2022 model to reflect California-specific fuel pathways, used to generate the carbon intensities (CIs) of those fuel pathways.

The ICAO-GREET version is used to estimate and verify the default core life cycle assessment values of the CORSIA-approved SAF pathways.