Solar energy can be utilized using two technologies – thermal and photovoltaic. Thermal solar power harnesses heat of sun directly like solar cooker etc and photovoltaic cell converts light into electricity or DC current. PV cell does not require direct sunlight so it can work in light cloudy conditions also. This technology was developed by NASA scientists in 1958 for their spacecrafts. A photovoltaic cell consists of layers of fine silicon wafers. When sunlight falls on these layers an electric field is generated across the layers and this result in flow of electricity. Semiconductors like silicon are used because they have a property of releasing electrons when solar energy falls on them, helping electrons to circulate and generate electricity.
When these photovoltaic cells are connected together they form a solar panel. PV solar panels come in mono crystalline, poly crystalline, amorphous and thin – film varieties. These solar panels are connected together in an array to produce electricity to do various things like heating water, generating light using solar lanterns and pumping water etc. The average lifetime of a PV panel system is approximately 20 years and it can be used independently or along with other conventional power sources. One should try to avoid any harm to solar panels to ensure its long life. Solar panels are usually covered with glass to avoid any moisture reaching parts of it and causing any harm.
Solar panels can be used to light up both interiors and exteriors of the house. One can use solar panels to light up their garden and drive way outside the house or use solar power to light up and heat up inside of any house. Solar panels can be used for sun bricks, solar powered security cameras, air crafts using solar energy, solar powered watches and phones etc.
Solar panels require proper maintenance else they wear out very soon. They should be kept away from any harm because if any harm is caused to the PV cells inside the panel it becomes useless.
Because of new technologies found by our researchers size and cost of PV cell has reduced drastically in recent years. Japan has invented a PV cell so thin that it can be used under clothing also. New technology of printable panels is also coming up in which these panels can be printed or coated directly on the surface exposed to sunlight.
The demand for solar panels is increasing in India because India receives plentiful solar radiations in its vast arid land areas. Moreover there are vast rural areas in India where the cost of providing conventional sources of energy is quite high so solar energy is a boon in these areas. According to Indian Meteorological Department states of Rajasthan and Gujrat receive maximum annual global radiations. Since large parts of Rajasthan are barren and scarcely populated central government has thought of setting huge solar power stations there. Depletion of fossil fuels and need for pollution free energy resource has made India recognize solar energy as its next big energy resource.