Scope 1 Emission

Scope 1 refers to emissions caused by activities owned or controlled by the organization that releases emissions directly into the atmosphere.  By burning resources such as oil and coal, the gases released into the atmosphere as a result of these (process emissions) are included in this scope. Scope 1 emissions include carbon dioxide (CO2), methane (CH4), and nitrous oxide (N2O) that are emitted from stationary and mobile combustion, and from inadvertent fugitive emissions.

Calculation methods for each type of source

Stationary Combustion

These sources include standard, biomass, and waste-derived fuels.  Fuel analysis method 1 is used to calculate stationary combustion emissions.

In this method, the following equation is used to calculate emissions:

Emissions = Fuel × EF

Here is an explanation of the equation:

  • Emissions = Mass of CO2, CH4, or N2O that is emitted
  • Fuel = Mass, volume or energy content of fuel that is combusted
  • EF = CO2, CH4, or N2O emission factor per mass, volume or energy unit

 

Mobile Combustion

In this method, the following equation is used to calculate emissions:

Emissions = Fuel/Distance × EF

Here is an explanation of the equations:

  • Emissions = Mass of CO2, CH4, or N2O that is emitted
  • Fuel/Distance = Mass or volume of fuel that is combusted or Distance that the vehicle traveled
  • EF = CO2, CH4, or N2O emission factor per mass, volume or energy unit

Emissions are calculated by using distance or fuel consumption data and with the emission factor.

 

Fugitive Emissions

Emissions from refrigeration and air conditioning equipment should be calculated separately for each facility. There are three methods for estimating emissions of HFCs and PFCs from refrigeration and air conditioning equipment:

  1. Mass balance approach;
  2. Simplified mass balance approach ;
  3. Screening method

Screening method, only be used to determine whether emissions fall below five percent of an organization’s total entity-wide emissions. The screening method cannot be used as a method for quantifying and reporting emissions if these emissions sources exceed five percent of total emissions.

Selection of Method

In order to determine the method, it is necessary to know what information about the source has been obtained;

Can you obtain data on your inventory of each refrigerant, including your base inventory and inventory changes due to purchases and sales?

  • If answer is yes: The mass balance approach
  • If answer is no: Simplified mass balance approach.

 

Mass Balance Approach

The mass balance approach is the most accurate method for determining HFC and PFC emissions. This method is particularly recommended for equipment manufacturers and for equipment users who service their own equipment.

To calculate HFC and PFC emissions using the mass balance approach, follow these three steps:

  1. Determine the base inventory for each refrigerant in use at each facility;
  2. Calculate changes to the base inventory for each refrigerant based on purchases and sales of refrigerants and changes in total capacity of the equipment;
  3. Calculate annual emissions of each type of refrigerant, convert to units of CO2e, and determine total HFC and PFC emissions for each facility.

 

Simplified Mass Balance Approach

If you do not have the necessary data to use the mass balance approach outlined above, you should use the simplified mass balance approach. This method may be used either by entities that service their own equipment or by entities that have contractors service their equipment. This method requires information on the quantity of refrigerant used to charge new equipment during installation, the quantity of refrigerant used to service equipment, the quantity of refrigerant recovered from retiring equipment, and the total full charges of new and retiring equipment.

To calculate HFC and PFC emissions using the simplified mass balance approach, follow these three steps:

  1. Determine the types and quantities of refrigerants used at each facility;
  2. Calculate annual emissions of each type of HFC and PFC;
  3. Convert to units of CO2e and determine total HFC and PFC emissions at each facility.

 

Screening Method

The screening method is intended to help roughly estimate the emissions and determine whether HFC and PFC emissions from refrigeration and air conditioning systems.

To estimate emissions using the screening method, follow these three steps:

  1. Determine the types and quantities of refrigerants used;
  2. Estimate annual emissions of each type of HFC and PFC; and,
  3. Convert to units of CO2e and determine total HFC and PFC emissions.