More energy reaches earth from the sun than could be converted by millions of power stations.
The sun’s energy costs nothing, but how can we use it?
We can use the sun’s energy to heat the water in our homes. One way this can be done is with a solar panel. This is a glass-topped box fixed to the roof of a building, facing the sun.
The inside of the box is painted black. Black is best at taking in, or absorbing, heat. Water flows through pipes inside the box. During daylight, this water is heated by the sun’s energy.
Heat can be produced by using mirrors to direct and concentrate the sun’s rays. One solar furnace in southern France uses a giant, curved mirror to collect sunlight from a series of smaller mirrors.
The mirror then directs the sun’s energy onto a huge furnace. A solar power station in the Mojave Desert, in the United States, uses 1,800 mirrors.
Solar cells, also known as photovoltaic cells, are made of layers of a material that produces electrical energy when light shines on it. The solar cell converts the sun’s energy into electrical energy.
Watches and calculators can be fitted with solar cells. We say that they are solar powered, although they use indoor lighting, too. Larger solar cells provide electrical energy in places that are far from normal electricity supplies.
Most artificial satellites are also powered by solar cells.