GHG Methodology

GHG Methodology

WMU has tabulated Scope 1 and Scope 2 Greenhouse Gas (GHG) inventory using the EPA’s Center for Corporate Climate Leadership’s Guidance.  As noted on EPA’s website (https://www.epa.gov/climateleadership/ghg-inventory-development-process-and-guidance), this Guidance was “developed by the World Resources Institute (WRI) and the World Business Council for Sustainable Development (WBCSD), which is the global standard for calculating corporate GHG emissions.”  Scope 1 emissions have been determined by following the EPA’s Guidance for emissions resulting from fuel consumed at WMU’s Robert M Beam power plant for electric generation and steam generation for building heating and cooling.  Scope 2 emissions have been determined by following EPA’s Guidance for emissions resulting from electricity generated elsewhere and purchased to support the WMU campus.

EPA’s Center for Corporate Climate Leadership GHG Inventory Development Process and Guidance can be found here: https://www.epa.gov/climateleadership/ghg-inventory-development-process-and-guidance#:~:text=A%20greenhouse%20gas%20(GHG)%20inventory,voluntary%20or%20mandatory%20GHG%20programs

Scope 1 emissions have been determined utilizing EPA’s GHG Inventory Guidance for Direct Emissions from Stationary Combustion Sources (https://www.epa.gov/sites/default/files/2020-12/documents/stationaryemissions.pdf) using the Fuel Analysis Method.  The Fuel Analysis Method is recommended as WMU does not employ a Continuous Emissions Monitoring System (CEMS) to measure CO2 directly.  The Fuel Analysis Method involves determining the carbon content of the fuel combusted and applying that carbon content to the amount of fuel burned to quantify CO2 emissions.  Equation 2 of the Fuel Analysis Method is recommended when the actual fuel heat content is known (as it is for WMU’s natural gas supply).  The total Scope 1 emissions from fuel combusted at the power plant are then determined utilizing the fuel heat content, the total plant fuel consumption, and the emission factor for converting natural gas fuel to emissions units.  The quantity of natural gas consumed is provided to WMU monthly from WMU’s gas supplier.

Scope 2 emissions have been determined utilizing EPA’s GHG Inventory Guidance for Indirect Emissions from Purchased Electricity (https://www.epa.gov/sites/default/files/2020-12/documents/electricityemissions.pdf).  The location-based method identified in the Guidance (as opposed to a market-based method) is most applicable to WMU.  Total electricity purchases are provided to WMU monthly from the local electric utility.  Emissions factors appropriate for electricity purchased at WMU’s location are determined utilizing eGRID data as recommended by EPA.  The Scope 2 emissions are then determined by multiplying the quantity of electricity purchased by the determined location-based emissions factors.

Definitions:

  • Greenhouse Gas Inventory – A list of emission sources and the associated emissions quantified using standardized methods.
  • Scope 1 Emissions – Direct GHG emissions that occur from sources that are controlled or owned by an organization (e.g., emissions associated with fuel combustion in boilers, furnaces, and vehicles).  EPA’s detailed methodology for determining Direct Emissions from Stationary Combustion Sources can be found here: https://www.epa.gov/sites/default/files/2020-12/documents/stationaryemissions.pdf
  • Scope 2 Emissions – Indirect GHG emissions associated with the purchase of electricity, steam, heat, or cooling.  Although scope two emissions physically occur at the facility where they are generated, they are accounted for in an organization’s GHG inventory because they result from the organization’s energy use.  WRI’s GHG Protocol Scope 2 Guidance containing EPA’s recommended methodology for determining Scope 2 emissions can be found here: https://ghgprotocol.org/sites/default/files/standards/Scope%202%20Guidance_Final_Sept26.pdf
  • Scope 3 Emissions – Indirect GHG emissions are the result of activities from assets not owned or controlled by the reporting organization but that the organization indirectly impacts in its value chain.
  • Fuel Analysis Method – A method of determining Scope 1 emissions based on the carbon content of fuel consumed using either fuel-specific information or default emission factors and applying that carbon content to the amount of fuel burned to quantify CO2 emissions.
  • Location-Based Electricity Emissions Factors – Emissions factors are developed based on average emission factors for the electricity grids that provide electricity to a given location.  In WMU’s case, this is based on EPA’s Emission Factors Hup containing the most recent eGRID subregion emission factors, which can be found here: https://www.epa.gov/egrid