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.