The Physics
An encyclopedia of scientific essays

Energy Consumption of the United States

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Bibliographic Entry Result
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Beursten, Bruce E., Theodore L. Brown & Eugene Le May Jr. Chemistry: The Central Science. Engelwood Cliffs, NJ: Prentice Hall, 1997. "In 1995 the US consumed a total of 9.2 × 1016 KJ" 9.2 × 1019 J
The World Almanac and the Book of Facts. New York: K-III Reference, 1998. "90.94 quadrillion Btu" 9.59 × 1019 J
USA Statistics in Brief--Income, Prices, Energy. Statistical Abstract of the United States. US Census Bureau. "Production (Quad. Btu.)
1990: 70.8
1995: 71.1
1996: 72.6"
7.46 × 1019 J
7.50 × 1019 J
7.65 × 1019 J
Hellman, Hall. Energy in the World of the Future. New York: M. Evans,1973. "… total figure for energy consumption in the US … to be about 70,000 trillion Btu's (in 1973)" 7.38 × 1019 J
International Energy Outlook 1998. Energy Information Administration. Department of Energy. "United States: 1995
90.4 Quadrillion Btu"
9.53 × 1019 J

Energy is the ability to do work and in the United States a lot of work needs to be done. Energy consumed by the United States is so large a number that it is often measured in quadrillion BTU which equals 1015 BTU, or British Thermal Unit.

Every year energy consumption increases by 5% in the United States and it is projected that energy consumption will surpass 100 quadrillion BTU by the 2000. In 1973 the energy consumption was 7.38 × 1019 J, and then in 1995 the energy consumption rose to about 9.5 × 1019 J. That's an increase of 2.0 × 1019 J over a span of 20 some odd years.

As one of the world's leading energy consumers we are aware that the energy supply is decreasing and our demand is increasing. Most of our energy comes from oil which, found in the Earth, is quickly disappearing. As the future comes we must find alternate forms of energy to supply our ever increasing demands.

Tommy Zhou -- 1998

Energy Consumption per Capita in America (1949-2000)

Energy is the compelling force of life. The fundamental concept was first discovered in the mid 1800s and was followed by the discovery of work-energy equivalency, law of conservation of energy, and the realization of energy in all different forms. However, it is important that in physics today, we have no knowledge of what energy is [1]. We can only observe it in different forms.

Energy is used is an equivocal phrase. What is meant is that around the world everyday, we are transforming a stored type of energy (gasoline, natural gas, oil, nuclear, hydroelectric, wind -- now in the form of electricity) into a new type of energy (heat for our tea, kinetic for our cars, light for our street lamps and computer monitors, and sound from our stereos). America happens to do this quite a bit. We are responsible for about a quarter of world's energy consumption [2] mostly due to our exuberant use of cars (a great many now SUVs), our electrical appliance use, heat for our homes, and the great amount of energy used in production and manufacturing in our country's vast industrial and commercial enterprises.

Energy consumption per person was investigated in this study from post WWII (1949) to recent years (2000). The data was excerpted from the historical data webpage at America's Energy Information Administration (which serves and compiles official energy statistics from the federal government) [3] and graphed year vs. trillions of joules of energy (see following page).

Our country has seen great economic and political changes, wars, and social unrest during this time. Many of these historical factors influenced our energy consumption. Additionally, since we are examining per capita consumption we can more accurately examine trends that aren't associated with our population increase over the fifty years.

The data was unable to be fit to a single regression line -- this is due to the varying trends in policy, prices, and technologies. I was able to fit three piecewise functions to the graph -- 1949-1973 (increasing power), 1974-1982 (quadratic peak), 1983-2000 (increasing linear). The values for the regressions are very extreme (due to the fact that year was left as the true year instead of year 1,2,3,4 and energy was transformed from quadrillions of BTUs to trillions of Joules), but the type of trend is accurate (very low mean sq. errors).

Although American energy consumption is far too complicated to be investigated and is beyond the scope of this report, we can try to summarize major influences in these three time periods.

Click for a larger image or to view the raw data file.
Source: National Energy Information Center.

From 1949-1973, America saw a boom of consumerism and economic prosperity, people bought cars, billions of gallons of gasoline, televisions, and industries were expanding and producing. This is why we see an exponential increase in consumption per person. However, by the end of this trend, Americans were using more energy than what was possible to be produced domestically and we were importing a great deal of it, predominantly oil from the middle east.

In late 1973, Arab oil embargoes curtailed our consumption (dramatic decrease from 1973-1975) and led to an energy crisis. The embargo was lifted (1975-1978) but then prices dramatically increased (1979-1981), and our consumption once again plummeted (this is why we see a peak from a partial polynomial curve).

From 1982 to present, we see a linear increase (possibly a very slight exponential increase) with slight dips in 1990-91 and 1996 due to oil price increases associated with the Gulf War. The relative linear increase can be associated with skyrocketing car sales coupled with greater gas efficiency, as well as skyrocketing computer and Internet use, as well as cell phones, and increasing natural gas consumption for heating in expanding industry.

  1. Feynman, Richard. Lectures on Physics Vol 1. Menlo Park, CA: Addison Wesley, 1963.
  2. Energy: Scientific Principles.
  3. National Energy Information Center.

Adam Kapelner -- 2002