The Book of Invention: Energy from The Sun

 

For millions of years, the Sun has given people a source of energy which is clean, cheap and absolutely natural. Without energy from the Sun there would be no life on Earth. But how do we control energy from the Sun (solar energy) to provide, For example, a constant energy for our homes? One solution is solar panels. These are large sheets of black-coloured glass which concentrate the heat and are positioned in such a way as to catch the rays of the Sun for as long as possible. Directly underneath the solar panel is a water tank, in which water is heated up by solar energy, giving a supply of hot water to the home.

Today, there are also installations which can transform solar energy into electrical energy. This is done by using solar energy to boil water. The boiling water turns a turbine connected to an electricity generator.

Another system uses photoelectric cells. Each cell is made of two layers of silicon, one on top of the other. The upper layer contains phosphorous, the bottom layer contains the element boron. When the light hits the zone of contact between the two layers, this makes the electrons of these two elements move, and this movement generates an electric current. Artificial satellites which orbits around the Earth are powered by this system of solar energy.

In recent years, there have been an increasing number of experiments to produce electricity from sources of energy which cause the minimum of pollution. During the course of these experiments, there have been trials to obtain electrical energy from the movement of sea waves through equipment. This consists of a series of paddles which are moved by the waves. The paddles push the water through pipes to turn the turbines inside, and these turbines provides the power for an electricity generator.