Endless Energy

Energy comes in different forms. Light is a form of energy. So is heat. So is electricity. Often, one form of energy can be turned into another. This fact is very important because it explains how we get electricity, which we use in so many ways. Electricity is used to light streets and buildings, to run computers and TVs, and to run many other machines and appliances at home, at school, and at work. One way to get electricity is to burn a fuel like oil or coal. This makes heat. The heat then makes water boil and turn into steam. The steam runs a machine called a turbine that produces electricity. Often, this electricity then goes into a public power system that sends it out, through wires, to homes, schools, and businesses over a wide area. This method for making electricity is popular. But it has some problems. Our planet has only a limited supply of oil and coal. They are not renewable fuels. Once they areused, they are gone forever. Also, they give off gases when they are burned. These gases may make the air dirty, or polluted, and some of them may change Earth’s climate.

Free and Clean Energy

Another way to make electricity uses sunlight. Sunshine is free and never gets used up. Also, there is a lot of it. The sunlight that hits the Earth in an hour has more energy than the people of the world use in a year.

A little device called a solar cell can make electricity right from sunlight (“solar” means having to do with the Sun). A solar cell doesn’t give off any gases. It doesn’t even make any noise. A solar panel is a group of solar cells that work together.

The use of solar cells is growing fast in the United States and many other countries