Stages of a Power Station

1. Coal stockpile

Coal is a fossil fuel. In Queensland it is mainly dug from large open-cut mines. The coal is then often delivered to the power station by train. It is stored in the stockpile until it is needed to provide energy for the power station.

2. Pulveriser

When the coal is needed it is taken to the pulveriser. The pulveriser crushes the coal into very small pieces. These pieces are as fine as talcum powder. This helps the coal to burn more efficiently in the boiler.

3. Boiler

The boiler is like a large room. In the room there are lots of pipes or tubes with water flowing through them. The coal from the pulveriser is burnt to produce heat. The heat boils the water so that it turns into steam. The steam is used to turn the turbine.

4. Turbine

The steam travels along pipes to the turbine. The turbine has many hundreds of blades. These blades are on an angle like the blades of a fan. The steam from the boiler hits the blades and turns the turbine. The turbine has a shaft attached to it. As the turbine turns so does the shaft. The shaft from the turbine is connected to the generator.

5. Generator

The generator is made up of a very large magnet and a stationary ring wrapped with a long wire. The magnet is attached to the shaft and is turned inside the ring. As the magnet turns an electric current is produced in the wire.

6. Generator transformer

The generator transformer is the last step in the process. The generator transformer increases the voltage of the electricity from 20 000 volts to 275 000 volts. This allows the electricity to be transported efficiently through the electricity transmission grid.
Other features you might have seen at a power station include the condenser and the water cooling tower. These are not directly involved in the generation of electricity but they help to make the provision of resources more efficient.

7. Cooling Tower

After the steam has turned the turbine it is piped to the condenser. Cold water is pumped from the cooling tower into the condenser where it is used to cool the steam. After circulating in the condenser the cooling water which is now about 10 degrees hotter, flows back to the cooling tower. The water is cooled by the air and then falls back to the bottom of the cooling tower to be recycled through the condenser again. Some of the heat in the water is released into the air in the form of water vapour. It is this water vapour that you can see coming out of the top of the tower if you pass by a power station.

8. Condenser

Water from the cooling tower goes through pipes in the condenser to cool the steam and transform it back into water. The water is pumped back into the boiler and the process starts all over again.