Monday, January 18, 2010

Solar Cells

by : Jakob Jelling

There are a number of people out there who would like to have the world using energy only from renewable energy resources, such as the sun. While this would be fantastic for people and the environment, the reality of how solar cells work doesn’t make this feasible in our current society. Scientists are working hard to examine how energy is currently converted from the sun into direct current energy we use in our homes. This article will discuss how solar cells work today, and what type of research is going on to try and improve them.

The solar cells you have likely come across in your daily life are also known as photovoltaics. Often you will not see just one solar cell, but a collection of solar cells that are combined together in order to produce larger amounts of energy. Photovoltaics are what converts’ light from the sun into electricity.

These photovoltaic cells are constructed of different materials – various types of silicon (amorphous, multi crystalline, and single crystal) are the more common and traditional materials used in solar cells. These materials are referred to as semi-conductors. As semi-conductors they allow the energy from the sun to enter into them and then store that sun energy and control the movement of that energy.

The energy moves in a particular current, and is transferred to the metal contacts that are attached to the tops and bottoms of the solar cell. Those metal contacts are what draws off the energy from the cell. Many cells together, connected by metal wiring create greater amounts of usable energy.
This is a very theoretical explanation of what goes on within a solar cell, and there are more considerations of the cells in reality that have to be accounted for when you are constructing solar panels. If the energy that goes into the solar cell amounted to the energy that was extracted from the solar cell, then it is likely more people would invest in solar energy solutions.

Unfortunately, the material used in the solar cell absorbs only visible energy from the sun. The light that gets to the solar cell is made of different wavelengths. In order for it to be absorbed by the cell a photon from the light wavelength needs to pair with an electron in the cell itself. These pairs cannot occur if the photon does not have enough energy to pair, or has too much energy to pair with an electron in the solar cell. It is this phenomenon that occurs that causes an up to seventy percent energy loss within the solar cell.

Other restrictions on materials used for conducting the energy also lead to energy loss. In an attempt to retain electricityBusiness Management Articles, metals used on solar cells at times prevent light from entering the cells. This is one reason getting the best angle for sunlight collection on a solar power system is important.

Current research is examining ways and different materials available that will force the solar cells to retain more energy and then become less expensive. The demand is increasing and prompting further studies on how solar cells work. Eventually science
will get to a point where these cells will become smaller and more economically feasible.

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