Sep 12 2009
How Do Solar Cells Work
There is a growing awareness by governments and the public at large that fossil fuels are a finite resource that continues to be used up at alarming rates in developed and developing countries. The realization that there may be little future for the planet if we continue to use these fuels has prompted governments to look for alternative energy resources. Most governments seem to be torn between embracing the renewable energy resources like wind, wave and solar power or opting for nuclear power despite public uneasiness at the use of nuclear energy. It seems that governments feel in their hearts that renewable resources are the way to go so they introduce policy to reward people for using solar power. But in their heads they feel that nuclear is tried and tested and has demonstrated that it can deliver energy in large quantities at a reasonable price. With this debate raging it seems topical to focus on solar energy and discuss how solar cells work to provide energy that we can use.
Solar cells, sometimes referred to as photovoltaic cells convert light energy into electrical energy. The most common type of solar cell is made from a silicon wafer.
The solar panels that you see on rooftops consist of many solar cells. They are typically aligned together to form a solar array and the solar panel is made up of numerous solar arrays. Solar panels normally have a large surface area because the more contact with direct sunlight the more electrical energy will be produced.
Photons are responsible for carrying the energy of direct sunlight. When photons strike the silicon cells at the right frequency they are effectively absorbed by the silicon. The absorption causes an electron to be ‘knocked loose’ from the silicon atoms in the solar cell.
This movement of electrons in effect creates an electric field. When a large number of solar cells can be linked together as in an array or as a grouping of arrays in either a parallel or serial configuration then the voltage and current of the electric field can be controlled. Thus this electric field can be stored in batteries or used to power electric appliances.
Solar cells have evolved as more research goes into creating solar energy. Initially solar cells were very expensive to produce and this made applying the technology to everyday use difficult. Solar cells are still quite an investment for the individual home owner but there are many grants that governments will give to make this investment more affordable. Electricity companies are also making solar installation easier and cheaper.
Solar power can be applied to many house and garden products. In recent years the cost of these appliances have become very affordable and saved money on energy bills. Learn more about solar powered appliances at http://www.solarpowerappliances.com/ The site has features on solar water heating, outdoor lighting and solar ovens. Adrian Whittle writes about using solar power and appliances that can utilize renewable energy sources.