There are many ways of making electricity. A lot of electricity is made using renewable sources of energy these days. Scientists have found ways of using the sun, wind and water to make electricity. There are still a lot of power stations that turn fossil fuels into electricity though. Coal is one example of a fossil fuel. Fossil fuels are substances that are made over a process of thousands of years – decaying plants and animals are compressed under layer upon layer of debris, until the pressure turns them into hard, dark coal. Fossil fuels are ‘non renewable’ because it takes thousands of years to make coal, but when we dig it up we destroy it quicker than it is being made.
Coal is turned into electricity by burning it. The coal produces heat when we burn it, and that heat is used to boil water, making steam. The steam rises, and is used to spin turbines, which are connected to generators. It is the generator that makes the electricity by spinning a magnet, which causes electrons to move around in a tightly coiled wire. Electrons can be either positive or negative, and when the magnetic field moves, the electrons will tend to follow it depending on whether they are positive or negative themselves.
This is similar to how wind turbines work �” the wind makes the turbine move, and the turbine spins the generator. The difference with coal based power is that with wind power, we have to wait for the wind to be strong enough to move the turbine. Coal can be turned into power at any time, as long as we have a supply of coal to burn.
Coal is in limited supply, however, and burning coal produces smoke and pollution. The governments of the world have agreed to try to limit the amount of carbon dioxide that each country produces, because they are worried that carbon dioxide is contributing to something called global warming. Burning coal produces a lot of carbon dioxide, so most countries are looking for alternatives to coal based electricity generation. Solar power is a clean and easy way of generating some electricity, and hydro-electric power is an option in countries with a lot of rivers. Nuclear power is something that many countries are exploring as well, although there are some people who do not like the idea of nuclear power, because of the safety issues that were highlighted when there was a disaster at a nuclear reactor in Japan.