The EPA divides the US electricity grid into 27 subregions, each with different generation mixes and emission intensities. The table below shows the output emission rate for each subregion - the primary factor used for GHG Protocol Scope 2 location-based carbon accounting.
?year=2024 to any lookup request for preliminary 2024 emission factors. Average change vs. 2023: -1.8% CO2e. Notable shifts: NYUP +12.3%, SPNO -9.6%, NWPP -8.3%, CAMX -5.8%. Source: Cornerstone Data (CC-BY-4.0), generated from EPA's open-source eGRID R pipeline. Default remains eGRID2023 Rev 2 below.
| Subregion | CO₂e (lb/MWh) | CO₂e (kg/kWh) | Carbon-free | Renewable | Top fuel sources |
|---|---|---|---|---|---|
| NYUP | 242.8 | 0.1101 | 74.1% | 41.8% | hydro 33%, nuclear 32%, gas 26% |
| CAMX | 430.0 | 0.1950 | 54.3% | 46.4% | gas 43%, solar 20%, hydro 14% |
| AKMS | 522.4 | 0.2370 | 68.9% | 68.9% | hydro 67%, oil 25%, gas 6% |
| NEWE | 543.2 | 0.2464 | 41.8% | 19.2% | gas 56%, nuclear 23%, hydro 8% |
| SRVC | 596.3 | 0.2705 | 49.8% | 9.9% | nuclear 40%, gas 39%, coal 10% |
| RFCE | 599.2 | 0.2718 | 40.4% | 4.0% | gas 54%, nuclear 36%, coal 5% |
| NWPP | 635.3 | 0.2882 | 58.2% | 55.1% | hydro 39%, gas 25%, coal 16% |
| AZNM | 706.2 | 0.3203 | 40.2% | 22.3% | gas 49%, nuclear 18%, coal 11% |
| ERCT | 736.6 | 0.3341 | 37.2% | 28.7% | gas 50%, wind 23%, coal 13% |
| SRMV | 741.7 | 0.3364 | 25.1% | 3.0% | gas 65%, nuclear 22%, coal 8% |
| FRCC | 784.8 | 0.3560 | 18.6% | 6.6% | gas 75%, nuclear 12%, solar 5% |
| SRSO | 846.0 | 0.3837 | 29.9% | 9.5% | gas 55%, nuclear 20%, coal 15% |
| NYCW | 865.7 | 0.3927 | 0.6% | 0.6% | gas 98%, other fossil 1%, oil 1% |
| SPNO | 867.7 | 0.3936 | 54.2% | 40.1% | wind 40%, coal 32%, gas 14% |
| SPSO | 875.6 | 0.3972 | 36.8% | 36.8% | gas 46%, wind 33%, coal 16% |
| SRTV | 903.3 | 0.4097 | 41.9% | 9.1% | nuclear 33%, gas 30%, coal 28% |
| AKGD | 905.1 | 0.4106 | 16.3% | 16.3% | gas 60%, coal 14%, hydro 14% |
| RFCW | 916.1 | 0.4155 | 36.0% | 7.6% | gas 38%, nuclear 28%, coal 25% |
| MROW | 926.6 | 0.4203 | 51.3% | 43.5% | wind 38%, coal 35%, gas 13% |
| RFCM | 976.0 | 0.4427 | 21.3% | 11.2% | gas 50%, coal 26%, nuclear 10% |
| RMPA | 1042.5 | 0.4729 | 41.9% | 41.9% | coal 32%, gas 26%, wind 26% |
| HIMS | 1133.3 | 0.5141 | 34.2% | 34.2% | oil 66%, wind 12%, geothermal 7% |
| NYLI | 1189.3 | 0.5395 | 6.5% | 6.5% | gas 87%, other fossil 5%, biomass 4% |
| SRMW | 1248.6 | 0.5663 | 31.6% | 15.2% | coal 51%, gas 17%, nuclear 16% |
| MROE | 1405.0 | 0.6373 | 17.3% | 17.3% | gas 43%, coal 39%, wind 5% |
| HIOA | 1499.0 | 0.6799 | 14.2% | 14.2% | oil 83%, solar 7%, wind 4% |
| PRMS | 1548.5 | 0.7024 | 2.3% | 2.3% | gas 44%, oil 39%, coal 15% |
Get this data by ZIP code, not just by subregion. Free API - no key, no signup.
Read the API docs →lb/MWh × 0.45359237 / 1000.Source: EPA eGRID2023 Rev 2, Table 1: eGRID Subregion Output Emission Rates. Released June 12, 2025. This is the most recent official EPA edition. Preliminary eGRID2024 factors are available via the API with ?year=2024 (source: Cornerstone Data, CC-BY-4.0).
The emission rates represent the output emission rate - emissions per unit of electricity delivered to the grid. This is the factor recommended by the GHG Protocol Scope 2 Guidance for location-based accounting.
The EPA publishes factors by subregion, not by ZIP code. To look up a specific address, you need a mapping from ZIP codes (specifically Census ZCTAs) to eGRID subregions. This mapping is built by intersecting ZCTA centroid coordinates with EPA subregion boundary polygons - a spatial analysis step that the EPA doesn't provide as a ready-to-use dataset.
Our API handles this mapping for 33,616 US ZCTAs (99.5% coverage), including edge cases like multi-subregion ZIPs and US territories.
Query emission factors by ZIP code, coordinates, or in bulk. See the API docs.
Try it now →emission-factors.com is an independent service. Not affiliated with the EPA. Terms · Privacy