Chapter 7
Energy Conservation
By Susan Stempleski
In this chapter students explore the uses of some common sources of energy and ways that individuals can conserve energy. The 50-minute lesson begins with a warm-up activity in which students discuss the meaning of the concept of energy conservation and why it is important to conserve energy. Next, students work in groups to brainstorm ideas and complete a chart outlining the ways people use some common energy sources. Then, individual students fill out a questionnaire to examine their own behavior and find out how energy efficient they are as individuals. The lesson concludes with a short writing activity in which students reflect on what they have learned in the lesson and list some actions they plan to take to conserve energy.
Through listening, speaking, reading, and writing activities on the topic of energy conservation, students improve their language skills by learning and using new vocabulary and concepts related to the topic. Some teachers may decide to present the activities described in the section on Classroom Applications in one 50-minute lesson. Other teachers may prefer to combine the activities with some of the materials outlined in the section on Internet Resources to develop a longer lesson or a more extensive unit of several related lessons.
Sources of Energy
Energy is often defined as the capacity to do work or the ability to make things move. It is the power that humans use to produce heat and drive machines, and it is an important part of our everyday life. Electrical energy turns on lights and computers, cools refrigerators, heats toasters, and brings pictures to television screens. Burning gasoline produces energy that powers the engines of motor vehicles such as cars, trucks, and buses.
The main sources of energy in the world are fossil fuels—coal, oil, and natural gas—and wood. (Most electricity, another major source of energy, is produced by coal-burning plants.) Some other sources of energy include wind power, water, solar energy, and nuclear energy.
Environmental Problems
Using some energy resources creates environmental problems. Today fossil fuels supply about 90% of the world’s energy needs. Burning fossil fuels for energy releases carbon into the air and contributes to the greenhouse effect. Burning fossil fuels also releases other chemicals that create smog and acid rain. These two forms of pollution—smog and acid rain—damage human health and the environment, including wildlife, water, and vegetation . The more energy people use, even in such everyday acts as turning on a light, taking a hot shower, or driving a car, the more pollution they help to cause.
Using fossil fuels means using them up. They are nonrenewable sources of energy; nature cannot re-create them at the very fast rates at which people are using them up today. At sometime in the future, all of these nonrenewable sources of energy will run out. The world will need to use other, renewable, energy sources such as wind power, wave power, geothermal power, solar energy, and hydroelectricity.
Using wood for energy also create environmental problems. More than two-thirds of the people in developing countries depend upon wood as their primary source of energy. Each year over 28 million acres of tropical forest are cleared for fuel needs, crop production, and cattle ranching. Forests are disappearing so quickly that they do not have time to regrow. This deforestation also contributes to the greenhouse effect.
Using nuclear energy causes other problems. Producing nuclear energy results in unwanted and dangerous by-products. When atoms are split to produce nuclear energy, hazardous nuclear waste is produced. It is not always easy to dispose of this nuclear waste safely.
Energy Conservation
Because using some energy resources creates environmental problems, energy conservation is important. Energy conservation means using energy without waste. Some common examples of energy conservation include turning off the lights when leaving a room, setting the thermostat lower in the winter, wearing a sweater to keep warm around the house, and riding a bicycle or walking instead of driving a car.
Some people think energy conservation means keeping their house too cold in the winter or too hot in the summer. But it is not necessary to be uncomfortable when conserving energy or using it more efficiently. We can conserve energy in a number of different ways: by doing without, by changing the way we live and the way goods and services are produced, and by using energy efficiently. When we practice intelligently, energy conservation may not even be noticed.
