Natural gas can reduce greenhouse gas emissions by 15% to 25% on a lifecycle basis compared to diesel vehicles. Fleets that operate natural gas vehicles can offer a lower emission service to their customers and reduce the environmental impact of their operations.
Natural Resources Canada has a lifecycle or “well-to-wheels” emissions model called GHGenius. It calculates the emissions from transportation fuel production, transmission, and use. The model compares the well-to-wheels emissions of natural gas vehicles to those of diesel and gasoline vehicles. The GHGenius model is based on Canadian fuel and supply sources.
Based on the model, a natural gas highway tractor trailer provides a 25.6 % reduction in greenhouse emissions compared to a diesel tractor trailer. For a truck that travels 200,000 kilometres per year, this represents an annual carbon benefit of about 70 tonnes. The majority of emissions occur during vehicle operation.
To calculate GHG reduction based on annual mileage:
The benefit calculated by GHGenius is on a “CO2-equivalent” basis. This means that impacts related to the three major greenhouse gases-carbon dioxide (CO2), nitrous oxide (N2O), and methane (CH4)-are included in the calculation. Natural gas primarily consists of methane, which is a greenhouse gas. Natural gas vehicles and stations are designed so as to minimize any release of methane.
There are several options available to reduce greenhouse gas emissions from highway tractors. Natural gas, whether as compressed natural gas (CNG) or liquefied natural gas (LNG), can be combined with aerodynamic devices, fuel efficient tires, and driver training to provide even greater benefits. The table below shows the relative benefits of natural gas and other GHG reducing options for Class 8 highway tractors