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Natural gas is produced at oil refineries like this one.  Photo by David Parsons.


Electricity from:
Natural Gas



Natural gas is the generic term used for the mixture of vapors that result from the decomposition of plant and animal materials over millions of years. Natural gas, along with oil and coal, is a fossil fuel and, similar to oil and coal, is found in underground reservoirs located in several areas of North America. The primary component of natural gas is methane, a hydrocarbon.

Natural gas is the cleanest of all the fossil fuels.

The stock of natural gas, like other fossil-based fuels, is limited and is therefore not a renewable resource. The combustion of natural gas produces only a fraction of the nitrogen oxide and carbon dioxide emissions of oil and coal, and also results in essentially no particulate matter or sulfur dioxide emissions. Natural gas therefore becomes an attractive "transition" fuel, as the energy supply moves away from polluting sources such as coal and nuclear sources and towards cleaner, renewable technologies.

Natural gas can be used as a fuel in conventional steam boiler generators, like other fossil fuels. However, new technologies using natural gas as their primary fuel are far more efficient than older combustion technologies. New state of the art combined cycle plants reduce fossil fuel use by as much as 40 percent.

Combustion turbines are based on jet engines. With the combustion turbine technology, the natural gas is burned, creating superheated gas, which is then pressurized in pipes and used to drive the turbine. Combined cycle technology is really the coupling of two electric generation technologies, and boosts efficiency by using the same fuel to generate electricity twice. Natural gas may also be used in fuel cell technologies that rely upon chemical reactions to create electricity at much higher levels of efficiency than can be obtained from fossil fuel combustion.


What are the environmental issues?

Natural gas creates significantly smaller environmental impacts than coal. On a Btu basis, natural gas combustion generates about half as much carbon dioxide, or CO2, as coal, less particulate matter, and very little sulfur dioxide or toxic air emissions. Natural gas combustion may, however, produce nitrogen oxides and carbon monoxide in quantities comparable to coal burning. Ongoing use of natural gas inevitably results in methane emissions, a very potent greenhouse gas contributing to global climate change. Natural gas drilling and exploration can negatively impact wilderness habitat, wildlife and public open space. Among the list of potential negative land impacts associated with natural gas are erosion, loss of soil productivity, increased runoffs, landslides and flooding.

If natural gas is compared to coal combustion, CO2 emissions are significantly reduced, but natural gas combustion still results in a net increase in CO2 emissions and therefore can contribute to climate change.

Gas plant operations may result in significant impacts on water resources, depending on the type of combustion technology and plant design. Combustion turbines do not use significant quantities of water; combined cycle power plants do have a steam-cooling phase that may require significant quantities of water.


Additional Information:
U.S. Dept. of Energy's Energy Information Administration (EIA): "Natural Gas Information at a Glance" http://www.eia.doe.gov/oil_gas/natural_gas/nat_frame.html

Union of Concerned Scientists:How Natural Gas Works
http://ucsusa.org/clean_energy/renewable_energy/page.cfm?pageID=84


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