The United States is the world's largest energy consumer in terms of total use, and ranks 7th on a per-capita basis.^[1] The majority of this energy is derived from fossil fuels: in 2005, it was estimated that 40% of the nation's energy came from petroleum, 23% from coal, and 23% from natural gas. The remaining 14% was supplied by nuclear power, hydroelectric dams, and miscellaneous renewable sources.^[2] Coal rail cars in Ashtabula, Ohio Fossil fuels are hydrocarbons, primarily coal, fuel oil or natural gas, formed from the remains of dead plants and animals. ... Pumpjack pumping an oil well near Sarnia, Ontario Ignacy Łukasiewicz - inventor of the refining of kerosene from crude oil. ... Coal Coal (IPA: ) is a fossil fuel extracted from the ground by underground mining or open-pit mining (surface mining). ... Natural gas is a gaseous fossil fuel consisting primarily of methane. ... A nuclear power station. ... Hydraulic turbine and electrical generator. ...

History^[3]

US energy consumption, by source, 1850-2000

From its founding until the late 1800's, the United States was a largely agrarian country with abundant forests. During this period, energy consumption overwhelmingly focused on readily available firewood. Rapid industrialization of the economy, urbanization, and the growth of railroads led to increased use of coal, and by 1885 it had eclipsed wood as the nation's primary energy source. Coal remained dominant for the next 7 decades, but by 1950, it was surpassed in turn by both petroleum and natural gas. While coal consumption today is the highest it has ever been, it is now mostly used to generate electricity. Natural gas, which is cleaner-burning and more easily transportable, has replaced coal as the preferred source of heating in homes, businesses and industrial furnaces. Wood burning is the largest current use of biomass derived energy. ... Electricity generation is the first process in the delivery of electricity to consumers. ...

Petroleum began the 20th century as a minor resource used to manufacture lubricants and fuel for kerosene and oil lamps. One hundred years later it had become the preeminant energy source for the U.S. and the rest of the world. This rise closely paralleled the emergence of the automobile as a major force in American culture and the economy. While petroleum is also used as a source for plastics and other chemicals, and powers various industrial processes, today two-thirds of oil consumption in the U.S. is in the form of its derived transportation fuels. Russian wick kerosene lamp. ... Karl Benzs Velo model (1894) - entered into the first automobile race An automobile (or motor car) is a wheeled passenger vehicle that carries its own motor. ... Petrochemicals are chemical products made from raw materials of petroleum (hydrocarbon) origin. ...

Current consumption

The U.S. Department of Energy tracks national energy consumption in four broad sectors: industrial, transportation, residential, and commercial. The industrial sector has long been the country's largest energy user, currently representing about 33% of the total. Next in importance is the transportation sector, followed by the residential and commercial sectors. Image File history File links USenergy2004. ... Image File history File links USenergy2004. ... The United States Department of Energy (DOE) is a Cabinet-level department of the United States government responsible for energy policy and nuclear safety. ...

Regional variation

Household energy use varies significantly across the United States. An average home in the Pacific region (consisting of California, Oregon, and Washington) consumes 35% less energy than a home in the South Central region. Most of the regional differences can be explained by climate. The heavily populated coastal areas of the Pacific states experience generally mild winters and summers, reducing the need for both home heating and air conditioning. The warm, humid climates of the South Central and South Atlantic regions lead to higher electricity usage, while the cold winters experienced in the Northeast and North Central regions result in much higher consumption of natural gas and heating oil. Official language(s) English Capital Sacramento Largest city Los Angeles Area  Ranked 3rd  - Total 158,302 sq mi (410,000 km²)  - Width 250 miles (400 km)  - Length 770 miles (1,240 km)  - % water 4. ... Official language(s) None Capital Salem Largest city Portland Area  Ranked 9th  - Total 98,466 sq mi (255,026 km²)  - Width 260 miles (420 km)  - Length 360 miles (580 km)  - % water 2. ... Official language(s) None Capital Olympia Largest city Seattle Area  Ranked 18th  - Total 71,342 sq mi (184,824 km²)  - Width 240 miles (385 km)  - Length 360 miles (580 km)  - % water 6. ... Note: in the broadest sense, air conditioning can refer to any form of heating, ventilation, and air-conditioning. ... Heating oil, or burning oil, also known in the United States as No. ...

Another reason for regional differences is the variety of building codes and environmental regulations found at the local and state level. California has some of the strictest environmental laws and building codes in the country, which may contribute to the fact that its per-household energy consumption is lower than all other states except Hawaii. This article or section does not cite its references or sources. ...

References

1. ^ World Resources Institute "Energy Consumption: Consumption per capita" (2001). Nations with higher per-capita consumption are: Qatar, Iceland, United Arab Emirates, Bahrain, Luxembourg and Canada. Except for Canada, these are small countries with a prominent energy-intensive industry such as oil refining or steelmaking.
2. ^ US Dept. of Energy, "Annual Energy Report" (July 2006), Energy Flow diagram
3. ^ US Dept. of Energy, "Energy in the United States: 1635-2000"
4. ^ US Dept. of Energy, "Manufacturing Trend Data" (2002), Table 2b
5. ^ US Dept. of Energy, "Annual Energy Outlook" (February 2006), Table A2
6. ^ US Dept. of Energy, "Buildings Energy Data Book" (August 2005), sec. 1.2.3
7. ^ US Dept. of Energy, "Buildings Energy Data Book" (August 2005), sec. 1.3.3

See also

• United States energy
• Energy policy of the United States
• Energy conservation