Explain : Solar cells

Explanation

Solar energy is useful only during day time. This limitation of using solar energy can be overcome by using solar cells that convert solar energy into electricity.
A typical cell generates a voltage of 0.5-1 V and can produce about 0.7 W of electricity when exposed to the sun.
Solar cell panel contains an arrangement of large number of solar cells, that deliver enough electricity.
Solar cells have no moving parts, require little maintenance and work efficiently without the use of any focusing device.
They can be set up in remote and very sparsely inhabited areas in which laying of a power transmission line may be expensive and commercially not viable.

The process of manufacture of solar cells is very expensive because of following requirements (i) use of special grade of silicon and (ii) use of silver for inter-connection of the cells in the panel.
Solar cells are used for following scientific and technological applications:
`rarr` The solar cells are used as the main source of energy artificial satellites and space probes like Mars orbiters.
`rarr` Solar cell panels are used in remote locations to operate Radio or wireless transmission systems or TV relay stations.
`rarr` Traffic signals, calculators and many toys are fitted with solar cells.
The solar cell panels are mounted on specially designed inclined rooftops for maximum absorption of solar energy.