Generating electricity

Where does electricity comes from?

Electricity is a very useful form of energy. It comes from special factories called power stations.

• In most power stations the following steps are necessary:

1.  The fuel is burned to release heat energy.
2.  This energy is then used to heat water (in the boiler), changing it into steam.
3.  The steam is then used to turn the turbine.
4.  The turbine turns the generator which produces electricity.
5.  The electrical energy produced travels through wires to houses, shops and factories.
6.  Machines called transformers change the voltage of the electricity travelling along the wires.

The energy changes in this process are:

Chemical energy → heat energy → kinetic energy → electrical energy

• In a hydroelectric power station there are no boilers. The kinetic energy of the falling water is transformed directly into the kinetic energy of the turbine blades.

The energy changes in this process are:

Gravitational potential energy → kinetic energy of water→ kinetic energy of turbine→ electrical energy