Methods: Emissions from electricity use
calc.energy-units.emissions · Version 0.1.0
Method
Multiply the energy by the subregion's eGRID2023 total output emission rate for each gas (lb/MWh), convert pounds to metric tons (0.45359237 kg/lb), and add CH₄ and N₂O to CO₂ with the 100-year global warming potentials eGRID uses (AR5: 28 and 265).
Assumptions
- The subregion's average rate over the whole year applies to every MWh, whenever it was used (location-based accounting).
- Total output rates include all generation in the subregion; they are not marginal or hourly rates.
Sources
- EPA, Emissions & Generation Resource Integrated Database (eGRID2023), eGRID2023, served snapshot 2026-10, Subregion file: total output emission rates (lb/MWh) for CO₂, CH₄, N₂O, and CO₂e
- EPA, eGRID2023 Technical Guide, January 2025, CO₂ equivalent emissions, PDF page 23: GWPs from AR5 without climate-carbon feedbacks (CH₄ 28, N₂O 265)
- NIST Special Publication 811, 2008, Appendix B.8, pound (avoirdupois) to kilogram
Worked examples
| Example | Independent source | Tolerance | Last result |
|---|---|---|---|
| 1,000 MWh in ERCOT (ERCT) | eGRID2023 ERCT CO₂ rate of 733.862 lb/MWh × 0.45359237 kg/lb | ±0.005 | Passed on Oct 31, 2026 |
Known differences from reference engines
None recorded.
Cite this tool
Emissions from electricity use, version 0.1.0. gridprims. https://gridprims.com/tools/calc/energy-units/emissions/