Solar energy can be harnessed successfully to mankind’s advantage. Solar cells or photovoltaic cells can produce electricity when exposed to sunlight.

A solar cell is made of silicon. The silicon used is a very carefully prepared from of the material. It causes the electrons in its molecular structure to move in a special manner when light is absorbed by the silicon. Each solar cell is chemically so prepared that there is an internal layer that acts as a barrier. In effect, it controls the direction of the flow of electricity that takes place, when the solar cell is exposed to light.

A solar cell is very much like a battery having a negative and positive side. It is able to provide a flow of electrical current when it is hooked into a circuit. The unique way by which a solar cell produces electricity is what attracted the attention of space scientists. These cells are now used to power most artificial satellites.

NOTE : The first solar-powered aeroplane was built by the American scientist and aviator, Paul Mcready. Equipped with a motor run by photovoltaic cells, it achieved a speed of approximately 3km/hr.