Putting Energy to Use
NARRATOR: Energy comes in many different forms. It can be stored in the chemical bonds that hold molecules together, carried in the motion of a spinning wheel, or held in a boulder sitting on a cliff. But energy isn’t a fixed thing. In fact, we convert it from one form to another all the time.
People discovered energy conversion thousands of years ago. While they couldn’t possibly have known what they were doing, when early humans burned wood to stay warm and keep predators away, they were actually converting the chemical energy stored in the wood into the heat and light of fire.
And wood was just the beginning. Chemical energy is also stored in coal, oil, natural gas, and radioactive materials—and these fuels have been critical to the development of modern human societies.
Fuels are used to generate three main forms of energy: thermal energy to heat our homes; mechanical energy to transport people and things; and electrical energy to power just about every other technology we use. From computers, to vacuums, to air conditioners.
The basic process and technology for producing most of our electricity is the same—whether it’s generated by a coal-burning power plant, a nuclear plant, or a renewable resource. In nearly all cases, one form of energy is converted into motion, or kinetic energy, by means of the spinning blades of a turbine. The turbine’s rotation is then used to turn the working parts of an electrical generator. This motion causes electrons to be pushed through wires inside the generator—converting kinetic energy into electrical energy—the electricity that is carried through power lines to our homes and schools.
The only real difference between one type of power plant and another is the energy source, or fuel, that is used to turn the generator.
Now, as some of the traditional energy sources are becoming harder to find and come with high environmental costs, scientists and engineers are looking for more innovative ways to produce the electricity we rely on.
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