|Earth Science. New York: Prentice Hall, 1987: 80||"105.6 Quadrillion BTU"||111.4 × 1018 J|
|McGraw-Hill Encyclopedia of Science and Technology, 7th ed. 1992.||"70.9(74.8*10^18)quad/Joules"||74.8–1018 J|
|Herda, D. J. & Madde, L Margaret. Energy Recourses. New York, 1991.||"The US alone consumed approximately 74.7 Quads of energy in 1981, or equal to what would be produced by nearly 14 billion barrels of oil"||78.8–1018 J|
|Table E1 World Primary Energy Consumption (BTU), 1987-1996. International Energy Annual 1996. Department of Energy, National Energy Information Center.||"111.19 Quads (1996)"||117.3–1018 J|
In Merrill Physics, energy is defined as "a non-material property capable of causing change in mater". There are many types of energy: kinetic, potential, electric, heat, solar, nuclear and many more.
Today, electrical energy is measured in kilowatts, joules, and BTUs. One BTU is the energy needed to raise the temperature of one pound of water by one fahrenheit degree. When measuring the amount of energy needs or used in a national scale the unit that is mostly used is the quad, which stands for 1 quadrillion BTU.
About one third of all energy produced in the US -- the world's leader in energy consumption -- goes to generate electricity. The biggest uses of energy are the industrial, commercial, and residential sectors.
The amount of energy needed rises yearly. This causes the consumption of natural resources like gas, oil, coal and uranium to rise which will lead to their depletion. This is why new sources of energy are necessary in order to maintain the lifestyle we have now.
The exact amount of energy consumed in North America is impossible to calculate this is why every source has a different measurement. It is impossible to count due to the huge amounts of energy involved. Since every machine consumes energy and since there are millions of machines in use, accounting for all the energy consumed in the United States is a nearly impossible task.
Alex Bershadskiy -- 1999