Sustainability & Risk / Green Building / Carbon Footprint - Background Data

Adding Emission Factors for Methane (CH4) and Nitrous Oxide (N2O)

Using the Emission Factors task, you add emission factors for methane and nitrous oxide by fuel, by sector, or by technology. Emission factors relate fuel consumption to the amount of greenhouse gas emitted when a specific amount of consumption activity occurs. Emission factors are expressed as the weight of pollutant divided by a measurement of the activity emitting the pollutant (for example, kilograms of particulate emitted per gigajoule of fuel consumed).

Emission factors are often averages based on a sample of measurement data. They describe a representative rate of emissions for a specific level of activity under specific operating conditions. Emission factors can vary by the fuel, the sector, and technology. For this reason, the IPCC defines factors for specific fuels and sectors or technologies. These default emission factors by major technology and fuel type are presented in the IPCC Guidelines.

The application uses the emission factor data when calculating methane and nitrous oxide emissions based on your fuel consumption. You obtain this emission factor data from the protocol you are using. For information on how CO2 emissions are calculated, see Calculating Emissions for Stationary Combustion.

You can associate an emission factor with a Fuel Base Code so that all fuels having that fuel base are assigned that emission factor.

To enter emission factors information:

  1. Select Carbon Footprint - Background Data / Emission Factors (Non-CO2).

    The Define Emissions Factors Versions, Sectors, Fuel Types, and Data form appears.

  2. To add an emissions factor protocol version:
    1. Click Add New > Emission Factors Version.
    2. Enter the following data:

      Version: Enter the version of the protocol you want to use for emission factors.

      Version Description: Enter a description for the protocol, such as the table number the data is found in, or the year the data is for.

    3. Click Save.
  3. To enter emission factors data:
    1. Click Add New > Emission Factors Data.
    2. Enter the following emission factors data:

      Sector Name: Select the sector for these emissions, such as Commercial/Institutional.

      Fuel Base Code: Select the fuel type that this emission factor is for.

      Fuel Mode: Select Fuel to define an emission factor for a particular fuel. Select Technology to define an emissions factor by technology.

      Fuel Name:

      • To enter emissions factor data for a fuel, select the name of the fuel. The Fuel Name lists shows fuels when you select Fuel as the Fuel Mode.

        Note: If you have created a Fuel Name that has the same value as the Fuel Base Code, this acts as a default for all fuels having this Fuel Base Code. See Defining One Emission Factor for all Fuels of a Particular Fuel Base.

      • To enter emission factors data for a technology, select the technology from the Fuel Name list. The Fuel Name list shows technologies when you select Technology as the Fuel Mode. See Adding Fuels for information on defining fuels and technologies.

      CH4 and N2O Units: Select the units used to measure the CH4 and N2O emission factors.

      Methane (CH4): Enter the emission factor for this fuel or technology for Methane emissions.

      Nitrous Oxide (N2O): Enter the emission factor for this fuel or technology for Nitrous Oxide emissions.

  4. Click Save.