When you’re traveling by train or riding along in a bus or car, you can easily spot a power station if you pass one. Many power stations have very tall towers called cooling towers. White clouds pour out of them. These are clouds of condensed water vapor, which is formed by steam as it mixes with cold air.
The power of steam
Power stations that burn coal or oil have three main parts— the boiler, the turbines, and the generator. The power station burns coal or oil to produce heat in its boiler. The boiler is lined with pipes carrying water, which boils and turns to steam. The steam is then piped to huge “wheels” fitted with hundreds of steel blades. These wheels are the turbines.
The steam rushes through the turbines at high speed and turns the steel blades. In a large power station, the steam passes through several turbines until almost all of its energy has been used up. The used steam then cools in the cooling towers and changes back into water. This changing process is called condensation. The water returns to the boiler and is heated up again.
Whether power stations use oil, coal or nuclear fuel, they all produce steam that drives huge turbine wheels.
Some of the heat energy produced by this coal-fired power station is used to make electricity. Most of the heat energy escapes up the tall cooling towers.
Inside the generator
The central rod, or shaft, of the turbine is connected to a coil of wire inside the generator. This coil, or rotor, is pushed around as the turbine wheels rotate. It rotates inside another coil, the stator, which is fixed and cannot turn. The movement of the rotor inside the stator generates electricity.
Fuel for power
Power stations need large supplies of water and fuel. They are usually built near rivers or lakes so a large supply of water is always present. Coal-fired power stations are sometimes close to coal mines so that the coal can be transported easily. Oil-fired power stations are supplied with oil by pipelines.