Optimization Model for reducing Emissions of Greenhouse Gases from Automobiles (OMEGA)

On this page:

Overview of OMEGA
OMEGA v2.5.0
OMEGA v2.1.0
OMEGA v1.4.56
OMEGA v1.4.1
OMEGA v1.4.0
OMEGA v1.3.1
OMEGA v1.0.2

Overview of OMEGA

OMEGA is a free, stand-alone computer application which has been developed by EPA to evaluate policies for reducing greenhouse gas (GHG) emissions from light- and medium-duty vehicles. This model is intended primarily to be used as a tool to support regulatory development by estimating compliance pathways for vehicle manufactures and the associated costs and effects of policy alternatives under consideration.

OMEGA 2.5.0

(supporting the 2024 Final Rulemaking for Multi-Pollutant Emissions Standards for Model Years 2027 and Later Light-Duty and Medium-Duty Vehicles)

Downloadable Materials

OMEGA 2.5.0 model executables
These self-contained packages are the same version of the model that EPA used for the FRM’s compliance and effects analyses.
- Compliance analysis executable file for Windows (exe) (April 15, 2024) and for Mac (command) (April 15, 2024).
- Effects analysis executable files for Windows (exe) (March 18, 2024) and for Mac (command) (March 18, 2024).
Compliance analysis packages, Central case
These .zip files contain the model inputs and outputs for analyses presented in the FRM.
- Light-duty central case (zip) (March 2024).
- Medium-duty central case (zip) (March 2024).
Compliance analysis packages, Sensitivity cases
- Light-duty slower BEV acceptance sensitivity (zip) (March 2024).
- Light-duty faster BEV acceptance sensitivity (zip) (March 2024).
- Light-duty high battery cost sensitivity (zip) (March 2024).
- Light-duty low battery cost sensitivity (zip) (March 2024).
- Light-duty no-trading sensitivity (zip) (March 2024).
- Light-duty lower BEV production sensitivity (zip) (March 2024).
- Light-duty no additional BEVs beyond no-action sensitivity (zip) (March 2024).
- Light-duty ACC2 sensitivity (zip) (March 2024).
- Light-duty reduced IRA sensitivity (zip) (March 2024).
- Light-duty no BEVs illustrative scenario (zip) (March 2024).
- Medium-duty high battery cost sensitivity (zip) (March 2024).
- Medium-duty low battery cost sensitivity (zip) (March 2024).
- Medium-duty no-trading sensitivity (zip) (March 2024).
- Medium-duty no BEVs illustrative scenario (zip) (March 2024).
Effects analysis packages
This .zip files contain the physical and cost effects files used for the cost-benefits analysis presented in the FRM.
- Light- and medium-duty effects (zip) (March 2024).

Model Support

EPA OMEGA Documentation.
Contact omega_support@epa.gov with questions about setting up and running the OMEGA model.

OMEGA v2.1.0

(supporting the 2023 Notice of Proposed Rulemaking for Multi-Pollutant Emissions Standards for Model Years 2027 and Later Light-Duty and Medium-Duty Vehicles)

Downloadable Materials

OMEGA 2.1.0 model executables
These self-contained packages are the same version of the model that EPA used for the NPRM’s compliance and effects analyses.
- Compliance analysis executable file for Windows (exe) and for Mac (command) (April 27, 2023).
- Effects analysis executable files for Windows (exe) and for Mac (command) (May 5, 2023).
EPA’s OMEGA Model Final Peer Review Summary Report (pdf) (1.6 MB, April 2023, EPA-420-R-23-010)
Version 2.1.0 is released with various changes and improvements in response to reviewers’ comments.
Compliance analysis packages, Central case
These .zip files contain the model inputs and outputs for analyses presented in the NPRM.
- Light-duty central case (zip) (April 27, 2023)
- Medium-duty central case (zip) (April 27, 2023)
Compliance analysis packages, Sensitivity cases
- Light-duty high battery cost sensitivity (zip) (April 2023).
- Light-duty low battery cost sensitivity (zip) (April 2023).
- Light-duty faster BEV acceptance sensitivity (zip) (April 2023).
- Light-duty slower BEV acceptance sensitivity (zip) (April 2023).
- Light-duty ACC2 sensitivity (zip) (April 2023).
- Light-duty no-trading sensitivity (zip) (April 27, 2023).
- Medium-duty high battery cost sensitivity (zip) (April 2023).
- Medium-duty low battery cost sensitivity (zip) (April 2023).
Effects analysis packages
This .zip files contain the physical and cost effects files used for the cost-benefits analysis presented in the NPRM.
- Light- and medium-duty effects (zip) (April 2023).

Model Support

EPA OMEGA Documentation.
Contact omega_support@epa.gov with questions about setting up and running the OMEGA model. Please note that all correspondence will be added to the rulemaking docket.
Video Tutorial: Getting Started with OMEGA

OMEGA v1.4.56

(supporting the 2016 Proposed Determination and 2016 Draft Technical Assessment Report (TAR) for Model Year 2022-2025 Light-Duty Vehicle Greenhouse Gas Emissions Standards)

The downloadable installation file below contains the application executable file and five sample Microsoft Excel input files. In addition, 2 zip files contain files used to generate technology costs used as inputs to OMEGA and the OMEGA input/output files used to generate results presented in the 2016 Proposed Determination and 2016 Draft TAR. Please note that the zip file is a large download.

Model Documentation v1.4.56 (pdf) (632K, EPA-420-B-16-064, July 2016)
This document contains descriptions of the OMEGA model's operation, input and output files, and algorithms.
OMEGA 1.4.56 Installation Files (MSI) (msi) (3.46 MB, July 2016)
OMEGA pre-processors, Technology and Benefit-Cost Analysis files and OMEGA runs used in the Proposed Determination analysis.
These files contain technology cost development files including battery and motor cost development; the OMEGA Input/Output files used in the Proposed Determination analysis; and the OMEGA Inventory, Cost and Benefit Tool and Input/Output files. Please see the contained readme file for additional guidance.
- OMEGA pre-processors (zip) (845 MB, November 2016)
- Technology and Benefit-Cost Analysis files (zip) (64.35 MB, November 2016)
- OMEGA runs (zip) (507.63 MB, November 2016)
OMEGA pre-processor, Technology cost development, and Input/Output files used in the Draft TAR analysis (zip) (696.83 MB, July 2016)
This file contains technology cost development files including battery and motor cost development; the OMEGA Input/Output files used in the the Draft TAR analysis; and the OMEGA Inventory, Cost and Benefit Tool and Input/Output files. Please see the contained readme file for additional guidance.
April 2017 revised OMEGA pre-processor, the TEB-CEB “Machine,” fixes formatting of technology codes on electrified vehicle packages where the safety-related net mass reduction cap is 0 percent.
Three files, two Excel workbooks each with unique technology costs and a text file of the corrected VBA code.
- April 2017 OMEGA “Machines” using VBA v4.29 (zip) (1.71 MB, April 2017)

OMEGA v1.4.1

(supporting the Final Rulemaking to Establish 2017 and Later Model Year Light-Duty Vehicle Greenhouse Gas Emissions Standards)

The downloadable installation file below contains the application executable file and five sample Microsoft Excel input files. In addition, a zip file contains the input files which were used to determine the technology cost estimates for the Final Rulemaking to Establish 2017 and Later Model Year Light-Duty Vehicle Greenhouse Gas Emissions Standards. Please note that the zip file is a large download.

Model Documentation v1.4.1 (pdf) (1.14MB, EPA-420-R-12-024, August 2012)
This document contains descriptions of the OMEGA model's operation, input and output files, and algorithms.
OMEGA 1.4.1 Installation Files (MSI) (msi) (1.57 MB, August 2012)
This file contains the OMEGA v1.4.1 application executable file and five sample input files.
Input and output files used in the Final Rulemaking (zip) (231.7 MB, August 2012)
This file contains the input and output files used in the the Final Rulemaking to Establish 2017 and Later Model Year Light-Duty Vehicle Greenhouse Gas Emissions Standards, as well as the benefits worksheet. Please see the contained readme file for additional guidance.

OMEGA v1.4.0

(supporting the Notice of Proposed Rulemaking to Establish 2017 and Later Model Year Light-Duty Vehicle Greenhouse Gas Emissions Standards)

OMEGA 1.4.0 Installation Files (MSI) (msi) (585.5 KB, December 2011)
This file contains the OMEGA v1.4.0 application executable file and five sample input files.
Input files used in Interim Joint Technical Assessment Report (zip) (5.49 MB, October 2010)
This file contains the input files used in the the Notice of Proposed Rulemaking to Establish 2017 and Later Model Year Light-Duty Vehicle Greenhouse Gas Emissions Standards, as well as OMEGA post-processors including the benefits worksheet.

OMEGA v1.3.1

(supporting the model year (MY) 2017 - 2025 Interim Joint Technical Assessment Report of September 2010)

The downloadable installation file below contains the application executable file and five sample Microsoft Excel input files. In addition, a zip file contains the input files which were used to determine the technology cost estimates for the MY 2017-2025 Interim Joint Technical Assessment Report. The model documentation provides details on the model’s input files, algorithms, and output files.

Model Documentation v1.3 (pdf) (695K, October 2010, EPA-420-B-10-042)
This document contains descriptions of the OMEGA model's operation, input and output files, and algorithms.
OMEGA 1.3.1 Installation Files (MSI) (msi) (610 KB, October 2010)
This file contains the OMEGA v1.3.1 application executable file and five sample input files. This version has some minor technical corrections relative to the version (1.3.0) used in MY 2017-2025 Interim Joint Technical Assessment Report.
Input files used in Interim Joint Technical Assessment Report (zip) (5.49 MB, October 2010)
This file contains the input files used in the Interim Joint Technical Assessment Report, as well as the benefits post-processor worksheet.

OMEGA v1.0.2

(supporting the MY 2012-2016 Light Duty Greenhouse Gas rulemaking)

The downloadable installation file below contains the application executable file and five sample Microsoft Excel input files. In addition, a zip file contains the input files which were used to determine EPA’s technology cost estimates for the EPA-DOT Joint Final Rulemaking (FRM) to Establish Light-Duty Vehicle Greenhouse Gas Emission Standards and Improve Fuel Economy. The model documentation provides details on the model’s input files, algorithms, and output files. A copy of the peer review report and EPA’s response to those comments can also be found below.

Model Documentation v1.0 (pdf) (422 KB, October 2009, EPA-420-B-09-035)
This document contains descriptions of OMEGA’s general methodology, the input and output files, and algorithms.
OMEGA v1.0.2 Installation file (MSI) (msi) (1.13 MB, October 2009)
This file contains the OMEGA v1.0.2 application executable file and five sample input files. This version was used in EPA’s Final Rulemaking to Establish Light-Duty Vehicle Greenhouse Gas Emission Standards. (Requires the patch below)
Patch for OMEGA v1.0.2 (zip) (26.88 KB, October 2009)
Input files used in EPA’s FRM (zip) (261.13 KB, October 2009) This zip file contains 6 Excel files which were used to calculate manufacturers’ technology cost in EPA’s FRM.
Input files used in EPA’s NPRM (zip) (1 MB, October 2009)
This zip file contains 28 Excel files which were used to calculate manufacturers’ technology cost in EPA’s NPRM.
Peer Review Report and Response to Comments (pdf) (2MB, September 2009, EPA-420-R-09-016)
This document contains the Peer Review Report, which is comprised of comments from three separate peer reviewers, and EPA’s response to those comments.