Long-Run Marginal Emission Rates for U.S. Electricity in 2021

Supplying modeled estimates of long-run marginal emission rates (LRMER) for the contiguous United States, produced by the Department of Energy's Cambium project. It includes workbooks for state-level and 20 GEA region-level geographic resolutions. The data is intended for analyzing emissions induced or avoided by long-term changes in electricity demand.

Use Cases

• Calculate levelized long-run marginal emission rates for specific states or GEA regions to estimate emissions from long-term electricity demand changes.
• Compare long-run marginal emission rates (LRMER) across different geographic resolutions, such as states versus the 20 GEA regions.
• Analyze the influence of projected grid changes and capital asset evolution on emission rates for the contiguous United States.

Strengths

• Data is provided at two distinct geographic resolutions: states and 20 GEA regions.
• Produced by the Department of Energy's Cambium project with detailed methodology documentation.
• Planned for annual updates, indicating ongoing maintenance.

Limitations

• The dataset consists of modeled estimates, not direct measurements, introducing inherent uncertainty.
• Specific row counts, column details, and sample data are unavailable for assessing granularity.
• Geographic coverage is limited to the contiguous United States.

Provenance

Source

Department of Energy, Cambium project.

Collection Method

Modeled estimates from the Cambium project, using tools like ReEDS and PLEXOS.

Time Range

2021 (project year).

Freshness

Data is from the 2021 Cambium project, with the record last updated in March 2026.

Geography

Contiguous United States, at state and GEA region (20 regions) resolutions.