California Electricity Emission Factor 2023

EPA eGRID2023 Rev2 · 3 eGRID subregions

Power plants in California emitted 394.8 lb CO2e per MWh generated in 2023 (0.1791 kg/kWh), 49% cleaner than the US average, according to EPA's eGRID2023 state rate. Their generation was 56% carbon-free and 48% renewable. For GHG Protocol Scope 2 location-based reporting, use the eGRID subregion factor of each facility's ZIP (below), not the state rate: power flows across state lines within a subregion.

394.8
lb CO2e / MWh (state)
0.1791
kg CO2e / kWh
56%
Carbon-free
48%
Renewable

eGRID Subregions in California

California's ZIP codes fall in 3 eGRID subregions. These are the Scope 2 factors; use the ZIP-level API to get the one for each facility.

SubregionNamelb CO2e/MWhkg/kWhCarbon-freeShare of CA ZIPs
CAMX WECC California 429.983 0.1950 54.56% 96%
AZNM WECC Southwest 706.189 0.3203 40.27% 2%
NWPP WECC Northwest 635.267 0.2882 58.25% 2%

Generation Mix

Solar18.8%
Wind6.5%
Nuclear8.2%
Hydro14.8%
Natural Gas43.7%
Biomass2.3%
Geothermal5.2%
Other Fossil0.7%

Generation by power plants in California, 2023 (EPA eGRID2023 state resource mix).

kWh to CO2 Calculator - California

Using the CAMX subregion factor (429.983 lb CO2e/MWh = 0.1950 kg/kWh), which covers 96% of California's ZIP codes; for other parts of the state look up the ZIP. Source: EPA eGRID2023.

How to Use California's Emission Factor for Scope 2 Reporting

For GHG Protocol Scope 2 location-based emissions reporting, multiply each facility's electricity consumption by the emission factor for its ZIP code's eGRID subregion. Facilities in different parts of California are in different subregions - use the API to get the exact factor by ZIP code.

curl "https://emission-factors.com/api/lookup?zip=YOUR_ZIP"

Other States Served by the Same Subregions (state rates)

Arizona
689 lb/MWh
Idaho
314 lb/MWh
Montana
1064 lb/MWh
Nevada
644 lb/MWh
New Mexico
774 lb/MWh
North Dakota
1298 lb/MWh
California
395 lb/MWh

Frequently Asked Questions

What is California's electricity emission factor?

For Scope 2 reporting, it depends on the ZIP: California's ZIP codes are in CAMX (429.983 lb CO2e/MWh, 96% of ZIPs), AZNM (706.189 lb CO2e/MWh, 2% of ZIPs), NWPP (635.267 lb CO2e/MWh, 2% of ZIPs). EPA's state rate for plants in California is 394.8 lb CO2e/MWh, 49% cleaner than the US average.

How do I calculate Scope 2 emissions for a California facility?

Multiply the facility's annual kWh by the kg/kWh factor of its ZIP code's eGRID subregion to get kg CO2e, and divide by 1,000 for metric tonnes. The emission factors API returns the factor for any ZIP.

How clean is California's electricity grid?

Power plants in California generated 56% carbon-free and 48% renewable electricity in 2023. At 395 lb CO2e/MWh, the state rate is 49% cleaner than the US average of 770.9 lb/MWh.

Get exact emission factors by ZIP code

33,700+ ZIP codes · All 27 eGRID subregions · CO2e, NOx, SO2, generation mix

Read the API docs · Scope 2 calculation guide