Natural gas is principally composed of methane -- usually 70 to 90%. Other components include ethane, propane, butane, nitrogen and carbon dioxide. Methane gas is low in carbon and high in hydrogen. According to the Energy Information Administration, carbon dioxide emissions are 30% lower from natural gas combustion than from oil and coal combustion. In addition, natural gas produces much less nitrogen oxide and sulfur dioxide -- both environmentally damaging greenhouse gases -- than coal or oil . While coal and oil create a great deal of ash particles as a result of combustion, natural gas produces next to none. Natural gas as an energy resource not only reduces the amount of greenhouse gas emissions that are responsible for global warming, but also improves the purity of air and reduces the precence of smog and acid rain in urban environments.
In terms of price per unit of energy output, natural gas is a more cost efficient energy resource than other fossil fuels and electricity. The two most common types of residential energy sources are electricity and natural gas; the DOE estimates that the price of electricity per British Thermal Unit (BTU) is nearly four times as great as that of natural gas in homes nationwide. Natural gas is also more efficient in terms of intangible costs such as maintenance and emergency cleanup. Natural gas appliances require little to no maintenance, and an underground pipe delivery system allows for easy transport, whereas oil and coal transport by motor vehicle or ocean tanker is costly and carries a greater risk of damage. Natural gas leaks pose a much lower risk of environmental damage, whereas alternative fuels like oil can cause multi-billion-dollar cleanup and disaster-relief operations, as demonstrated by the BP oil spill of 2010.
For decades, American industry and consumers have relied on the the oil-producing countries of the Middle East, especially for transportation fuel in the form of gasoline. More than 97% of natural gas used in the United States comes from North America, and 84% comes from the United States itself. As natural gas--burning vehicles become more efficient and better known, the United States can enjoy a much greater degree of energy independence as well as easy access to nearby fuel.
Research and development in natural gas energies continue to expand the possibilities of natural gas. Natural gas--powered fuel cells provide a promising new method of delivering clean and efficient electricity. The majority of electricity today derives from the combustion of fuel oil, a relatively inefficient process that produces harmful pollutants. Fuel-cell technology generates electricity with no moving parts, no atmospheric emissions and high energy output per unit of natural gas input. While natural gas fuel cells remain expensive and inapplicable for practical, everyday use, technological advancements continue to improve the prospect of natural gas fuel cells as a key source of electricity. Liquified natural gas (LNG) presents another technological prospect; whereas coal and oil cannot be reduced in volume, LNG stores at one six hundredth of its size in gas state. As LNG becomes more prevalent, the costs of natural gas transport will decrease significantly.