Photovoltaic (PV) cells:
- Photo = light
- Voltaic = electricity
- Convert sunlight directly into electricity.
- Made of special materials called semiconductors such as silicon, which is currently used most commonly.
- Basically, when light strikes the cell, a certain portion of it is absorbed within the semiconductor material. (The energy of the absorbed light is transferred to the semiconductor)
- The energy knocks electrons loose, allowing them to flow freely.
- This flow of electrons is a current, and by placing metal contacts on the top and bottom of the PV cell, we can draw that current off for external use, eg. to power a calculator.
- This current, together with the cell's voltage, defines the power (or wattage) that the solar cell can produce.
Edited from,
~http://science.howstuffworks.com/environmental/energy/solar-cell1.htm
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