Many people prefer to use energy sources that do not harm the natural world. These are often called alternative energy sources. Solar energy, wind energy and water energy are alternative energy sources.
These turbines use wind energy to create electricity.
Heat from the Sun warms the air around our planet. The warm air rises. As it does so, cool air sinks. The movement of air forms wind, which turns wind turbines. These turbines turn a generator, and this creates electricity. A group of wind turbines is called a wind farm.
Solar power can be used with other energy sources.
Sometimes, solar power systems have a ‘back-up’ energy supply for times when energy from the Sun is not enough. This may be other alternative energies, such as wind or water energy, or it may be a fossil fuel such as natural gas.
This machine is called a tokamak. It makes energy by copying the Sun.
The Sun makes its energy by joining, or fusing, atoms together in a process called fusion. For this to happen, the atoms have to be heated to 100 million degree Celsius. A machine called a tokamak has carried out fusion trials. A much larger version is being built in France by international teams and could provide a source of alternative energy.