Emission Factors
What is Emission Factors?
Emission factors are coefficients that quantify the emissions of a particular pollutant per unit of activity. They are essential for calculating greenhouse gas emissions from various sources. Below are examples of emission factors for different activities:
Examples of Emission Factors
Electricity Consumption
- Grid Electricity (U.S.): Emission Factor: 0.45 kg CO2e per kWh
- Renewable Energy: Emission Factor: 0 kg CO2e per kWh (assuming 100% renewable)
Fuel Combustion
- Natural Gas: Emission Factor: 0.053 kg CO2e per MJ
- Diesel: Emission Factor: 2.68 kg CO2e per liter
- Gasoline: Emission Factor: 2.31 kg CO2e per liter
- Propane: Emission Factor: 1.51 kg CO2e per liter
Transportation
- Passenger Vehicles (Gasoline): Emission Factor: 0.24 kg CO2e per mile
- Freight Trucks (Diesel): Emission Factor: 0.28 kg CO2e per ton-mile
- Air Travel (Domestic Flights): Emission Factor: 0.133 kg CO2e per passenger-mile
Industrial Processes
- Cement Production: Emission Factor: 0.90 kg CO2e per kg of cement produced
- Steel Production: Emission Factor: 1.85 kg CO2e per kg of steel produced
Waste Management
- Municipal Solid Waste (Landfilling): Emission Factor: 1.1 kg CO2e per kg of waste
- Recycling: Emission Factor: Varies
Example Calculations Using Emission Factors
Example 1: Calculating CO2 Emissions from Electricity Consumption
Data: 10,000 kWh of electricity consumed in a month
Emission Factor: 0.45 kg CO2e per kWh
Calculation:
CO2 Emissions=10,000 kWh×0.45 kg CO2e per kWh=4,500 kg CO2e
Example 2: Calculating CO2 Emissions from Diesel Fuel Consumption
Data: 500 liters of diesel consumed by a fleet of vehicles
Emission Factor: 2.68 kg CO2e per liter
Calculation:
CO2 Emissions=500 liters×2.68 kg CO2e per liter=1,340 kg CO2e
Example 3: Calculating CO2 Emissions from Air Travel
Data: 1,000 passenger-miles flown on domestic flights
Emission Factor: 0.133 kg CO2e per passenger-mile
Calculation:
CO2 Emissions=1,000 passenger-miles×0.133 kg CO2e per passenger-mile=133 kg CO2e