73 Energy Resources-Low

ENERGY RESOURCES Written by David Dreier

Introduction Long long ago, people used very little energy. They got all the energy they needed from food. Then they learned how to control fire. People began to use fire for light, heat, and cooking. Today we use large amounts of energy. We use it to fuel our cars and to make electricity. We also use energy to make many products. Our energy needs are still growing. This book will look at energy resources in the past, present and future.

Electrical Energy Without energy, nothing can happen. Nothing can move, and no work can get done. We need energy for everything we do. Energy can change from one form to another. For example, light energy can change to heat energy. Both heat and light can be used to make electricity. Electricity is our most important form of energy. Think about all the ways you have used electricity today.

Generators Electricity is a flow of tiny particles called electrons. All matter is made of atoms. Electrons whirl around the center of each atom. That center is called the nucleus. Most of the electricity we use is made by large machines called generators. A generator has two main parts: magnets and coils of wire. The magnets make electrons flow through coils of wire. The flow of electrons creates an electric current.

A place where electricity is made is called a power plant. In most power plants, a fuel is used to boil water and make steam. The steam rushes through a machine called a turbine. The turbine has blades that spin when steam hits them. The turbine is attached to a generator and makes it spin. This makes electrons flow in wire coils and produces an electric current.

We use many sources of energy in today's world. These energy sources are either renewable or nonrenewable. Nonrenewable resources are fuels that cannot be replaced after they are used. Oil is an example of a nonrenewable resource. Renewable resources never run out. These resources include energy from the Sun and wind.