Let us start with something in the sky. Lightning is a kind of electricity. Benjamin Franklin showed that lightning is electricity. It happens when electric charge builds up in a storm cloud and then jumps to the ground. Now look at what things are made of. Atoms are made of protons, neutrons and electrons. Rubbing can move electrons from one thing to another. That is how static electricity starts. Electric charges that are alike push each other apart. Static electricity can make your hair stand on end.
Now let us see how it moves and how it is made. Electricity involves electrons moving from place to place through conductors. Metals let it flow through them easily. Glass, rubber, wood and plastic do not. A battery can make it flow through a wire. It only flows when it has a complete path, called a circuit. Power generation depends on a discovery Michael Faraday made in 1831. Moving a magnet through a coil of wire can make electricity flow in the wire. A generator turns the energy of motion into electricity.
Now let us see where it is made. Electricity is made at power plants. Here are some ways to make it. Moving water can spin a turbine to make it. Wind can spin the blades of a wind turbine to make it. Most wind turbines have three blades. Wind is caused in part by the sun heating the air unevenly. Solar panels can use sunlight to make electricity. People use electricity to light their homes.
Thomas Edison invented a long-lasting light bulb around 1879. His Pearl Street Station in New York City began sending out electricity in 1882. Most of the electricity we use today is alternating current (AC). Alternating current can be changed to higher or lower voltages with a transformer. Now let us see how it reaches us. Power lines carry electricity over long distances. From a substation, smaller, lower-voltage lines bring it to neighborhoods and homes.
Some safety rules matter a lot. If you see a power line on the ground, stay away from it and tell a grown-up right away. Never fly a kite near power lines. Never climb a power pole, or a tree that is near power lines. Never put your fingers or other objects into an outlet. To unplug something, hold the plug and never pull on the cord. Never use anything with a cord or plug around water.
Words to know
- electrons: tiny particles
- generator: makes electricity
- turbine: a spinning machine
- transformer: changes voltage
- alternating: kind of current
