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Compressed Natural Gas for Municipal Fleets

Reference Number: MTAS-705
Reviewed Date: 11/28/2022

The University of Tennessee Municipal Technical Advisory Service (MTAS), Clean Cities Coalition of Tennessee, Tennessee Renewable Energy and Economic Development Council (TREEDC) and the Tennessee Gas Association (TGA) are important resources available to interested fleets across the state. Natural gas is certainly abundant and much cheaper than petroleum. Natural gas can be used for city garbage trucks, police vehicles, and service vehicles. This guide presents the economic and environmental benefi ts of compressed natural gas along with case studies and siting tips for compressed natural gas stations.

Compressed natural gas, also known as CNG, is a fossil fuel substitute for gasoline (petrol), diesel or propane/LPG. More familiarly, it is the type of gas used in stoves. This gas remains clear, odorless and non-corrosive. Although its combustion does produce greenhouse gases, it is a more environmentally clean alternative to those fuels and is much safer than other fuels in the event of a spill. This is true because natural gas is lighter than air and disperses quickly when released.

Most natural gas is formed from three different types of wells; natural gas-and-condensate wells, oil wells and coal bed methane wells. However, more than 90 percent of the natural gas used in the United States comes from domestic or other North American sources. Increasing demand for natural gas in power plants will require new supplies from non-North American countries, increasing our dependence on foreign sources of energy. Delivering CNG is not as difficult as it may seem. With local vehicle fueling stations owned and operated by private companies and local governments, transportation can be easy and effective. CNG can also be imported via pipeline. The natural gas must be stored in thick-walled steel, aluminum or composite tanks built to last more than 20 years.