Solar energy got from the sun is a very useful form of energy like atomic and wind energy .the problem of rising cost of fuel like oil and gas and the pollution dirtiness’ of the atmosphere caused by them have made scientist work on solar energy for man future use. about half of the solar energy is light ,about half is infrared radiation heat energy etc in rays and very little ultraviolet radiation
In order times in china Egypt the middle east Greece and Italy solar energy was used to evaporate salt water change into vapour to get salt .crop drying through solar heat was also common in the 19th century it was used for preparing wine in chile south America in the early 20th century it was used in Egypt to run an engine for pumping irrigation from the Nile.
In modern times the main use of solar energy in to change it into thermal energy of heat as that of coal and gas. Solar rays hit a flat plate collector which absorb a lot of heat. This flat plate collector then use for water heating, house heating, air conditioning and for getting salt from salt and pure drinking water from the see water. Solar water heater are used in Australia ,Japan and America .In air conditioning flat plate collector supply heat to operate an air conditioner .In solar evaporation saltish water is made to evaporate from pounds and the salt is got .in solar distillation pure water vapor is collected in storage tank.
Scientist are trying to convert solar energy to electric energy through solar cells. a solar cell is an invention that directly changes solar radiation to electric energy .space ship get their electric power through solar cells .further they are being used to provide power to radios telephones and other wireless equipment .light houses at sea get their power supplies from them at present the cost of producing electricity from solar cell is very high .
Heat engines 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 is warmer then at the depth .heat flows from the area of higher temperature to that of a lower one. so if we make this heat of the warm water flow through a heat engine ,the heat energy can be converted to the mechanical or electric energy .power plant can thus use thermal energy especially in warm water .
In Japan and some other countries small plant grow in the sea by absorbing .these plant are dried and then use as a food .
There have been attempt to make solar cars in Europe and elsewhere .these cars run on electric energy instead of oil .the car batteries are charged with solar energy provide the electric energy however at present batteries are too heavy and are charged over long hours. solar energy may be the answer to many of our energy problems