EPA greenhouse gas reporting and emission rates

March 2024

The U.S. Environmental Protection Agency’s (EPA’s) mandatory national greenhouse gas (GHG) reporting program requires regulated natural gas utilities, and some of their largest customers, to report GHG emissions from their operations. The EPA website includes resources to understand the rule and an online tool to see if it applies to your company.

Electric utility energy mix and emission rates

This electric energy mix and emission rate information is provided for retail electric customers of We Energies, a regulated utility of WEC Energy Group (WEC) operating in the state of Wisconsin. The emission rates are supplied for customers to estimate their environmental footprint from electric energy supplied by We Energies, such as Scope 2 (indirect) greenhouse gas emissions.

Emission rates are calculated using total emissions and megawatt-hours from generation by owned and jointly-owned facilities, and from long-term power purchase arrangements. The CO2 equivalent emission rate includes all sources mentioned previously, wholesale sales and net emissions from MISO purchases and sales. The emission rates apply to retail electric utility customers of We Energies, except for customers of Energy for Tomorrow®, the We Energies Green-e Certified renewable energy program that is offered to all retail electric customers.

Emissions from electric generation facilities are calculated in accordance with the U.S. Environmental Protection Agency mandatory Greenhouse Gas Reporting Program regulations under 40 CFR Part 98. The energy resource mix represents net generation from We Energies-owned facilities, as well as generation acquired through long-term power purchase arrangements.

WEC and We Energies reserve the right to use all or some of the environmental attributes associated with generation from renewable energy sources in future years to comply with renewable energy standards or other regulatory requirements, or to sell to third parties the environmental attributes such as renewable energy credits, offsets, allowances and the avoided emissions of greenhouse gases. All information is provided on a voluntary basis, could be subject to change, and has not received independent third party verification. Neither WEC nor We Energies makes any assurances regarding the use of this information by external parties for marketing or other sustainability claims.

We Energies energy mix and emissions1

  2021 2022 20232
Emission Rates: Owned energy + Purchased power arrangements (lbs/MWh)
Carbon dioxide (CO2)3 1,062 950 973
Methane (CH4) 0.016 0.015 0.015
Nitrous oxide (N2O) 0.015 0.013 0.013
Carbon dioxide equivalent (CO2e)3,4 1,067 955 977
Sulfur dioxide (SO2) 0.05 0.04 0.03
Nitrogen oxides (NOx) 0.31 0.28 0.27
Energy resource mix: Owned energy + Purchased power arrangements
Energy from owned generation + purchased power arrangements (MWh) 29,772,985 28,567,014 29,299,562
Coal 37.1% 29.7% 31.6%
Natural gas 28.9% 33.6% 32.4%
Nuclear - long-term PPA 29.2% 30.5% 30.6%
Renewable energy 4.8% 6.2% 5.4%
Hydroelectric 1.5% 1.8% 1.5%
Biofuels 0.9% 1.4% 1.3%
Wind 2.3% 2.8% 2.4%
Solar 0.1% 0.2% 0.2%
CO2-Equivalent (CO2e) Emission Rate4,5: Total net CO2e / Customer Load (lbs CO2e/MWh)
Customer Load (MWh) 26,153,676 25,934,319 24,969,504
CO2-Equivalent Emission Rate (lbs CO2e/MWh)3 982 899 804

1 Table includes data for purchased power arrangements that were not included in previously available emissions data.

2 Rates for 2023 are preliminary and subject to change after regulatory reporting.

3 Biogenic emissions are not included in rate calculations.

4 Global warming potentials for calculating CO2-equivalents: CO2 = 1 ton; CH4 = 25 tons of CO2; N2O = 298 tons of CO2.

5 Methodology assigns emissions from contracted generating facilities and market purchases to the utility. Market purchases and sales use regional estimates from EIA CO2 rates by fuel type and MISO fuel mix data.

Information about natural gas delivered by We Energies

If your company is required to report greenhouse gas emissions or chooses to analyze its carbon footprint, you may need information about natural gas delivered by Wisconsin Electric Gas Operations or Wisconsin Gas LLC. The EPA’s default emission factors for natural gas for CO2 and CH4 and N2O are appropriate to use for the natural gas we distribute along with WEC Energy Group’s leak rate of 0.55 kg/mmBTU. The amount of natural gas consumed can be found on your bill or in the My Account section of our website. As a service to customers, we provide the heating value of your natural gas below*.

Wisconsin Electric Gas Operations

Higher Heating Value (HHV) - (MMBtu/Mscf)
  2018 2019 2020 2021 2022 2023 2024
Jan 1.046 1.052 1.048 1.048 1.051 1.05 1.055
Feb 1.040 1.044 1.054 1.057 1.053 1.046 1.048
Mar 1.046 1.051 1.050 1.054 1.046 1.04 1.047
Apr 1.042 1.052 1.056 1.054 1.049 1.046 1.048
May 1.040 1.052 1.053 1.058 1.051 1.045 1.051
Jun 1.054 1.058 1.046 1.057 1.048 1.048 1.054
Jul 1.055 1.061 1.051 1.056 1.048 1.056 1.063
Aug 1.044 1.060 1.056 1.055 1.053 1.057 1.058
Sep 1.049 1.062 1.058 1.054 1.056 1.053 1.054
Oct 1.054 1.058 1.061 1.057 1.05 1.049  
Nov 1.052 1.054 1.056 1.055 1.049 1.052  
Dec 1.051 1.051 1.052 1.053 1.056 1.053  

Wisconsin Gas LLC

Higher Heating Value (HHV) - (MMBtu/Mscf)
  2018 2019 2020 2021 2022 2023 2024
Jan 1.044 1.048 1.051 1.048 1.05 1.053 1.056
Feb 1.041 1.046 1.053 1.054 1.051 1.053 1.056
Mar 1.046 1.050 1.052 1.052 1.046 1.048 1.058
Apr 1.043 1.053 1.060 1.053 1.048 1.046 1.058
May 1.041 1.053 1.054 1.055 1.05 1.049 1.056
Jun 1.052 1.059 1.050 1.055 1.053 1.055 1.052
Jul 1.050 1.054 1.050 1.05 1.053 1.057 1.062
Aug 1.048 1.056 1.056 1.056 1.055 1.057 1.057
Sep 1.054 1.059 1.062 1.057 1.054 1.059 1.057
Oct 1.056 1.057 1.059 1.058 1.052 1.057  
Nov 1.053 1.055 1.052 1.053 1.052 1.056  
Dec 1.049 1.052 1.048 1.054 1.057 1.059  

Standard temperature: 60°F
Standard pressure: 14.7 psia
Measurement standard: GPA 2172-09

* Data on this page represent an average heating value for the system and may differ from data that meets state or local regulatory requirements and is used for billing purposes. Accordingly, the data is provided solely for informational purposes and not for billing purposes. We make no claim or representation that the data provided is accurate and make no warranties express or implied, including but not limited to, fitness for a particular purpose, including EPA compliance. No party should rely on such data, including, but not limited to, for billing purposes.