Solar Energy and Photo-voltaic's

Solar energy is obtained from sunlight. It has been used by humans for things such as heating, cooking food , drying clothes,  and removing salt from seawater. 

Solar cells, which you can see on calculators and satellites, are also called photo-voltaic cells (photo means light and voltaic means electricity). Photovoltaic cells convert sunlight directly into electricity.

How Photovoltaic Cells Work

Photovoltaic cells are made from special materials called semiconductors, most commonly silicon. 

• For solar cells, a thin silicon wafer is specially treated to form an electric field, positive on one side and negative on the other.
• When light energy strikes the solar cell,electrons are knocked loose from the silicon (or other semiconductive material). 
• If electrical conductors are attached to the positive and negative sides, forming an electrical circuit, the electrons can be captured as electricity, which can then be used to power a light or other load. 

Uses of Solar Power

• A number of solar cells electrically linked together and mounted in a frame is called a photo-voltaic module. 
• This is what you see on rooftoops of solar powered houses, like the one at left.  
• They also use photovoltaic modules to power the international space station.
• Solar power can be used in a home either to supplement the electricity that the home receives from the power grid or to provide all of the electricity needs of the household.  
• In some parts of the country, people who have excess solar energy can actually sell power to the electricity providers.  
• The installation of solar panels has become more affordable and easier to install.

 Fun Facts

• Did you know that the world's largest solar plant is in the Mojave desert ?
• The first photo-voltaic module was built in 1954 by Bell Laboratories.
• Albert Einstein discovered the foundation on which photo-voltaic technology is based.