The Fundamentals of Energy

The Fundamentals of Energy
Energy, the capacity to do work, is an essential part of everyday life for almost every human being. Be it a commodity, an ecological resource, a social necessity, or used for strategic purposes (Lecture notes, January 7th, 2002), energy holds great significance at an international, national, and household level. The main fossil fuels: coal, natural gas, and oil, supply about 85% of the fuel energy used in the United States. (Kraushaar, Jack J., and Robert A. Ristinen. Energy and the Environment. New York: John Wiley & Sons, Inc., 1999. (page 2) This high percentage of energy usage causes the fundamentals of energy and its properties to become an important and essential topic to explore. Energy can be measured in many different ways.
1 Btu, the British thermal unit, represents the amount of energy required to raise the temperature of one pound of water one degree Fahrenheit. Calories and joules are two other energy units, relatable to a Btu in this fashion: 1 Btu = 1055 Joules = .252 Calorie. (Lecture notes, January 11th, 2002) These energy units are essential in measuring power, the rate of spending energy or doing work, or the energy spent per unit time. (Power = Energy/Time) Power can also be measured in watts (1 joule/second), and horsepower (746 watts or 2,545 Btu/hour). Power, more important than energy due to the necessity of energy being delivered at certain time rate, can be derived from the many different forms of energy produced in the world today. The Energy Information Administration divides the forms of energy into the following categories: heat (thermal), light (radiation), mechanical, electrical, chemical, and nuclear. From these different forms, two types of energy can be found, potential or stored, and kinetic or working, energy. These forms of energy remain very different, for example chemical energy, stored in bonds between atoms in a molecule and released by chemical reactions, could not seemingly be more dissimilar to electric energy, resulting from the motions of electrons and generated by the rotation of a conductor in a magnetic field. (Lecture notes, January 21st, 2002) Interestingly enough however, all forms of energy can, in principle, be transformed from one form to another without loss. (Kraushaar, Jack J., and Robert A. Ristinen. Energy and the Environment. New York: John Wiley & Sons, Inc., 1999. (page 9) The First Law of Thermodynamics, a law of energy conversion, states that, ?Energy is conserved; energy cannot be created or destroyed, but it can be converted to one form or another?. Energy conversion is also important in changing heat to work, the product of force times the distance through which the force acts. (Kraushaar, Jack J., and Robert A. Ristinen. Energy and the Environment. New York: John Wiley & Sons, Inc., 1999. (page 8) The Second Law of Thermodynamics explains, ?Heat cannot be completely converted into work? and the portion not used goes to increase the entropy of the universe. (Lecture notes, January 30th, 2002) Entropy, or disorder, increases in any energy conversion process. Work is related to order, while heat is a function of disorder. Because waste heat does not equal zero in any conversion, energy efficiency is also an important element in energy usage. Efficiency is considered the ratio of useful output to total input, or E= work/heat. Efficiency is always less than 100%. System, or cumulative, efficiency determines the overall efficiency of using a primary energy source for a specific purpose. (Lecture notes, February 6th, 2002) With so much energy being used everyday, the idea of efficiency for best conservation is crucial for every energy consumer. Energy remains to be a central issue in our world today. As recent as this week, an editorial in U.S. News and World report discusses the role of energy. ?Long term, we must reduce the nation?s thirst for energy. But this doesn?t mean, as some suggest, doing without. Energy contributes much to our quality of life.? (Zuckerman, Mortimer B. ?Speaking the Truth About Energy.? U.S. News and World Report. 18 Feb. 2002) Due to the importance placed on energy, an even elementary understanding of energy concepts and fundamentals may help to aid smart energy usage and conservation for our future. Energy is our capacity to do work, and work must always be done.

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