by LJ Martin
Most of the power used in homes, shops and factories comes in the form of electricity. With all the talk of efficiency, renewable energy and carbon footprints, it is important to know a bit about how electricity works. This will help you to understand the issues surrounding electricity generation, transmission and use.
In this guide, we will cover the basics of electricity.
Electricity GenerationThe first thing that you need to know about electricity is that it is inextricably linked with magnetism. This is the single most important fact that will help you understand its generation and transmission.
If you take a coil of wire, and move a magnetic field around nearby, an electrical current will be generated in the coil. Well over 99% of our electricity is generated in this way.In a power station, movement energy is converted into electrical energy simply by spinning a magnet which is surrounded by coils. An electromagnet is used rather than a normal magnet, as this is lighter and more efficient, even when you account for the small current needed to energize the electromagnet itself. This magnet is spun by hooking it up to a turbine.
The two main types of renewable energy power station, i.e. wind and hydro, work by directly turning the turbine with movement harnessed from wind or water respectively.
Coal, gas and nuclear power stations work by generating heat. This heat is used to boil water, and the resulting steam is used to spin a steam turbine, which spins the magnet, which generates an electrical current in the coils.There are in fact renewable energy power stations which use steam turbines. Biomass power stations are similar to coal power stations but are carbon neutral, because they burn organic material such as wood or naturally generated methane. Solar-thermal power stations use mirrors to focus the sun's heat onto one spot, where it is used to boil water to drive a steam turbine. These need an enormous amount of sunshine, so are only found in deserts.
So, electrical generation is very simple. A magnet, a few coils of wire and a source of heat or movement are all you need. Next we will talk about electricity transmission.|