The Sun as a Source of Energy
· What is solar energy? Energy from sun is known Solar Energy. Solar energy is the radiant energy produced by the Sun. This source of energy is renewable. This source of energy is used world-wide by many people.
· Solar energy is a very useful form of energy like atomic and wind energy. About of the solar energy is light, about half is infrared radiation (heat, energy, etc.in rays) and very little ultraviolet radiation.
· In modern times, the first main use of solar energy is to change it into thermal energy (of heat as that of coal or gas). Solar rays hit a flat collector which absorbs a lot of heat. This flat plate collector is then used for water heating, house heating, air-conditioning and for getting salt from salt water and pure drinking water from sea water.
· Scientists have converted (change) solar energy to electrical energy through solar cells. A solar cell is an invention (device) that directly changes solar radiation to electrical energy.
· Heat engine are being used to convert solar energy to mechanical energy. This mechanical energy is used directly or again converted to electric energy for operating machines.
· We can use the solar energy or heat stored in the sea. Most of the solar energy that comes to the world is taken by the sea. The water at the surface of the sea is warmer than at the depth.
· In Japan and some other countries small plants grow in the sea by absorbing sunlight. These plants are dried then used as food.
· There have been attempts to make solar cars in Europe and elsewhere. These cars run on electric energy instead of oil. The cars batteries charged with solar energy provide the electric energy. However, at present the batteries are too heavy and are charged over long hours. Solar energy may be the answer to many of our energy problems.