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What are solar cells and how do they work?

Solar cells are devices which convert solar energy directly into electricity.  The most common solar cells function by the photovoltaic effect.  Photo- means light and -voltaic means electrical current or electricity.  (light-electricity)  A solar cell supplies direct current (DC) electricity that can be used to power DC motors and light bulbs among other things.  Solar cells can even be used to charge rechargeable batteries so that electricity can be stored or transported for later use when the sun is not available.
[You can save for rainy days and long dark nights!!]

Solar cells provide DC electricity similar to batteries however, batteries differ because they operate through a process known as an electrochemical reaction.  This process will provide an electrical current (electro-) from a chemical reaction (-chemical) that occurs inside the battery.  When you hook up a light or motor to the battery, also known as a load, the reaction begins and electrons flow as shown in the picture: "Simple Battery Circuit".  DC electricity is different from the AC electricity used to power the TV, refrigerator, and other appliances in your home however, DC can be converted to AC when needed.

Simple Battery CircuitD

Solar cells produce DC electricity from light.  Sunlight contains packets of energy called photons that can be converted directly into electrical energy.  You can’t see the photons but they hit the cell and produce free electrons that move through the wires and cause an electrical current as shown in the picture: "Simple Solar Panel Circuit".  The electrical current is the electricity that powers the light bulb.  Although you can't see the photons you can see the light and you can assume that the amount of photons hitting your solar cell is related to the amount of light hitting your solar cell.  A greater amount of light available means a greater amount of photons are hitting your solar cell and the more power you get from it.

Simple Solar Cell CircuitD

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