What are Solar Cells and how are they used

You will have probably seen calculators that get there power from solar cells and as long as there is enough light they seem work forever, but the cells can be used in many other ways.

At the side off roads powering road signs and call boxes and in some cities parking meters. Powering satellites in space and nowadays helping home owners create their own electricity. The cells you see around you are photovoltaic cells.

Photovoltaic, as the word implies (photo = light, voltaic = electricity), is the process of converting sunlight directly into electricity. Photovoltaic cells are made of special materials called semiconductors such as silicon. When light strikes the cell, a certain portion of it is absorbed within the semiconductor material. This means that the energy of the absorbed light is transferred to the semiconductor. This energy knocks electrons loose, allowing them to flow freely. The cells also all have one or more electric fields that act to force electrons freed to flow in a certain direction, thus creating a current which by using metal contacts at the top and bottom of the cell can be used to power an external device.

Usually, the cells are electrically connected, and combined into "modules", or solar panels. Solar panels, have a sheet of glass on the front, and a resin encapsulation behind to keep the cells out of the rain, hail, etc. They will be connected in a series of modules so that the voltage created by the cells add together. It will be these panels you see on top off homes