Why Is Milk White?: & 200 Other Curious Chemistry Questions (2013)
8. Chemistry in the World
How do we get electricity?
Electricity is mostly mechanically produced. Mechanical energy is turned into electrical energy in machines called generators.
Electricity and magnetism are two sides of the same thing. Moving electrons create magnetic fields. Moving magnetic fields cause electrons to move. In a generator, a magnetic field is made to move near copper wires. The electrons in the wires begin to move, and the moving electrons are what we call electricity.
Moving electrons can heat up wires as they move through them. Electric stoves and incandescent lights work by heating up wires this way. Since moving electrons create magnetic fields, and magnets can attract one another, we can make electric motors to power our gadgets around the house.
The electricity that comes out of the plug in your house is made by a generator, but there are other ways to make electricity. It can be made directly from heat in a simple device called a thermocouple. Twist together two different kinds of wire, such as copper wire and iron wire, and when you get the twisted part hot, it makes electrons move.
Electricity can also be made from light using solar cells or from pressure by using a piezoelectric ceramic, such as those in electric lighters. Electricity can be made by moving electrons on an insulator past some sharp wires in a Van de Graaff generator or chemically by building a battery.