Summary of Electricity Basics

Now we can sum up the basic principles that explain how electricity is generated, transmitted and distributed.

Electricity and magnetism are closely linked. Moving a magnetic field around a coil of wire will generate an electrical current in that wire. Passing an electric current through a coil will generate a magnetic field.

Power stations work by spinning electromagnets. The moving magnetic fields generate electricity in coils of wire. The magnets may be spun directly by harnessing the movement of an energy source such as wind or water. Otherwise, an energy source such as biomass, coal or nuclear can be used to heat steam, which spins a turbine connected to the magnets.

The same electrical power can be transmitted either as high voltage / low current, or as low voltage / high current. Power equals voltage times current.

Wires lose electrical power as heat due to their resistance. A small reduction in current results in a large reduction in power loss, because power loss equals current squared times resistance. The longer a wire is, the higher its resistance will be.

Power is transmitted over long distances at high voltage to reduce the current and therefore reduce power lost as heat.

Transformers can be used to step voltage up or down. Step-up transformers convert low voltage / high current electricity to high voltage / low current for transmission. Step-down transformers then reduce the voltage to a level that can be used in homes, offices and factories. They do this using magnetic fields. Transformers only work with alternating current (AC).

So, there you have the basics of electricity. You know how electricity is generated from movement or heat, why electricity is transmitted long distances at high voltage, and how the voltage is increased and decreased. Now you should be able to follow some of the issues surrounding electricity and the environment.