Given the fact that this unit will be implemented at the elementary level with second language learners in mind, it is a challenge to make this topic as concrete as possible so that students can relate to it in their own lives. For such a purpose, a series of basic lessons are set up so that the children have the background knowledge needed to explore the less contextualized concepts that attempt to be addressed as an answer to the above questions.
Energy in Our lives
As the price of fossil fuels reaches its highest level since the energy crises in the 1970’s our dependence on fossil fuels is ever increasing and more indispensable to the well being of our economies and society. The higher demand for fossils is due mainly to energy-dependent economies. Without energy most developing and industrial societies would be unable to maintain their economic growth and subsistence. Without the use of an energy source, our societies would crumble. It is therefore of vital importance that we begin educating our students on how our reliance on different sources of energy affects our daily lives, the role it plays in our day-to-day activities, and the way that the acquisition, transport and production of energy affects us all.
Almost everything we see around us, the cloths we wear, the food we eat, the houses we live in, the paper we write on, the vehicles we drive, all need energy to be created or transformed from some natural resource to the final product. Without some form of energy, the “raw” materials cannot be transformed so that they can be utilized for their intended use.
At the same time, without some type of source of energy, many of the machinery used during the production and manufacturing could not operate. Therefore, we can begin looking at energy from two different perspectives: 1) everything we consume makes usage of energy in the production and manufacturing process; and 2), energy is needed to run machinery, cars, light up homes, computers, etc.
Where does energy come from?
There are both renewable and nonrenewable forms of energy. According to the Encarta World English Dictionary (1999), renewable energies are those that are “able to be sustained or renewed indefinitely, either because of inexhaustible supplies or because of new growth.” This is the case of solar, hydraulic, and wind sources of energy. Nonrenewable forms of energy originate in fossil fuels, that is, from the breakdown of organic matter through millions of years into coal, oil, and natural gas. One of the main problems with fossil fuels is that there is a limit to the amount there is, and that in the process of combustion, they release pollutants into the atmosphere. The majority of fossil fuels are used to create electricity.
In all these processes some forms of energy is used to produce other forms of energy. But before we take a closer look at these two sources of energy, we must begin with a simple and general definition of what energy is.
What is energy?
Energy is the capacity of a system to do work. Without energy our society would be unable to perform. For example, the “heating value” of a fuel is used to measure energy. The most common units of energy are the calorie and the BTU (British Thermal Unit).
Why is energy so important in our lives?
Life on earth makes uses and depends, in one way or another, on some sort of energy. Without energy our human body would be unable to perform respiratory, circulatory, or digestive functions to name a few. Plants would be unable to complete the chlorophyll process of converting the light from the sun’s rays into chemical energy. Motors would be unable to perform without the use of a source of electric energy.
Energy plays an integral part in the progress of human kind. Since the beginning of mankind, we have made use of wood, water, and fossil fuels as a means of heating and making machines work.
California’s energy crisis in the past years has brought to everyone’s attention the limitations of an energy dependent society gone awry because of the politics of energy. In contrast, over 180,000 independent systems in the United States produce the majority of energy they consume via passive-solar energy and wind, power cells and other alternative renewable sources of energy. In these systems efficiency is a key component decreases the dependency on other non-renewable sources of energy such as coal and other fossil fuels.
In today’s society, the cost of energy from fossil fuels is increasingly higher in terms of production costs, and in the amount of pollution that it emits. Car and power plants could benefit from new technologies that would increase the efficiency of the engines and power plants, decrease the pollutants they emit, and make those machines last a much longer time.
The top consumers as well as producers of energy are the United States, Russia and China. In terms of other energy producing countries, we encounter Saudi Arabia, Canada, United Kingdom, Iran, Norway, Australia, and Mexico. These countries are rich in nonrenewable energy sources. The top energy consumers reflect highly industrialized societies, in the case of China, India, and Brazil, also some of the most populous countries. Behind the United States, China and Russia we have Japan, Germany, India, Canada, France, United Kingdom, and Brazil.
History of energy
Since the beginning of history, people have looked for ways of making work easier. At first they domesticated animals in order to perform hard labor. With simple inventions such as the wheel, the lever, and the ramp, they made it possible to move their civilizations forward and accomplish great projects. They also made use of wood and coal to heat up their homes, in addition to water to mill wood and ground grain.
It is through the use of fire and water that the first steam engine came to be. Hero of Alexandria has been credited with the invention of the first steam engine sometime between 150 BC and AD 150. Yet, it is through the study of some of the pioneers such as James Watt (1736-1819) with his improvements to the steam engine of Thomas Newcomen (1663-1729) and some of his successors, that we begin to observe how these discoveries caused significant changes in the history of civilization.
Some of the most noteworthy pioneers of the history of humankind in relation to energy are: George Simon Ohm (1787-1854) who was able to define the relationship between voltage, currents, and resistance (Ohm’s Law) of great consequence to the field of electricity; Michael Faraday (1791-1867) known as the father of the electric motor, electric generator (dynamo), electric transformer and electrolysis. James Prescott Joule (1818-1889) shared in the discovery of the conservation of energy (1st Law of Thermodynamics). Thomas Edison (1847-1931) invented the light bulb, incandescent electric lamp. Rudolph Diesel (1858-1913) patented the internal combustion engine, which changed manufacturing and transportation. It is in 1876 that German engineer Nikolaus Otto, based on Alphonse Beau de Rochas proposed four-stoke cycle, builds and patents the gasoline powered auto-cycle engine, otherwise known as the four-stroke Otto cycle.
Types of energy
There are many types of energy that support and enhance life on earth. The most important type of energy is the one that originates in fossil fuels (oil, natural gas, coal). Fossil fuels are the remnants of millions of years of sediments of organic matter and represent the highest percentage of all the sources of energy. In the Unites States alone 39% of the sources of energy is from oil, 24% from natural gas and 23% from coal. That leaves only 14% of the energy consumed from other sources such as nuclear, hydropower, solar, etc.
How is the energy produced? What different types of energies are used around the world? Is there any pattern of usage of energy across the country and the world? What are the most important factors that affect energy production, consumption, and waste?
Forms of Energy
Energy comes in many different forms. Based on the 1st law of thermodynamic that states that energy cannot be destroyed, but only transformed, many of the forms of energy can be transformed to other types of energy. The most important forms are:
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- Mechanical energy includes potential and kinetic. Potential energy is the energy that is stored in a system while the kinetic is the one created from the movement of matter.
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- Solar or radiant energy is generated by the sun’s light and heat.
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- Thermal energy relates to the heat of an object.
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- Chemical energy is the one stored in the chemical bonds of molecules.
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- Electrical energy is the energy produced through the movement of electrons.
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- Electromagnetic energy is the energy associated with waves.
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- Nuclear energy refers to the one used in the nuclear atom’s structure.