How Solar Cells Work?

We have all seen calculators and other things that do not need batteries and some that do not have an “off” button. They will work as long as there is light and they seem never to break down. Have you seen larger solar panels such as emergency road signs, call boxes and other such items and in parking lots in order to power the lights? These larger panels may not be as common as the solar powered calculator that we all now use, but they are there and not too hard to spot if you know what to look for. Photovoltaics, as they are known, have been used as far back as l958 to power satellites’ electrical systems in space. Now they are being used more and in less exotic ways. This technology is used in new devices all of the time in such things as sunglasses to electric vehicle charging stations.

There has been a hope for the use of electricity from the sun for many decades. This is a great hope because on a bright and sunshiny day the sun’s rays give about one thousand watts of energy per square meter of the earth’s surface. If that energy could be collected we would have enough energy to power our homes and our office free of charge. Solar cells convert that sun’s energy directly into electricity.

The solar cells used in our calculators and the satellites are called photovoltaic cells and can convert sunlight into electricity. A solar panel is a module made up of a group of cells connected electrically and set into a frame. The solar panel can be grouped into a larger panel. Photovoltaic cells are made of a special material called semiconductors such as silicon which is currently used. When light hits the cell a portion of it is absorbed by the semiconductor’s material thereby, transferring the energy of the absorbed light to the semiconductor The energy loosens the electrons letting them flow free. This flow of electrons is a current and with metal contact at the top and bottom of the photovoltaic cell the current can be drawn off for external use. The current with the cell’s voltage which is a result of the built in electric field explains the power or wattage that the solar cell can produce. That is the basic process of how a solar cell works.

Solar panels are being used by some to collect the sun’s rays to power their homes. It seems like a simple way to get you electricity without paying the power company, but what if the sum doesn’t shine? In that case you will either have to buy power from the power company and sell it back when you have accumulated more than you need. The power you get from your solar panels is stored in a generator for use when you need it. The solar panels work in conjunction with windmills or wind turbines to generate enough of the energy needed to electrically run your home.