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Photovoltaic Solar Energy

by: darrenclemen923 | Total views: 9 | Word Count: 627 | Date: Fri, 12 Feb 2010 Time: 8:08 AM | 0 comments

Photovoltaic panels are used to convert solar energy directly into DC electricity. Currently they are the most common device we have for this purpose. The electricity, once created, can be used immediately or stored in a battery for future use.

How photovoltaic panels convert solar energy is a subject of advanced physics. In simple terms we can say they take advantage of new age materials and a phenomenon called the photoelectric effect. Solar energy on the atomic level displaces electrons, which in turn creates the flow of electricity.

Historically photovoltaic panels were limited to space age technologies. They are used in satellites and the space stations where they reliably and continuously convert solar energy. As an added bonus, the Sun's radiation is at least 50% more powerful once we break into Outer Space.

In recent times photovoltaic panels have been converting solar energy for residential homes in far away places. The cost of a photovoltaic array will often offset the costs of routing power transmission cables from the Electrical Grid. When this distance exceeds 1 mile, then the prospects of converting solar energy with photovoltaics makes more and more sense.

When considering solar energy, one must first establish that they have proper amounts of solar radiation. There are two types of radiation we must think about. The first type is beam radiation, which are the direct rays of the Sun we receive on a clear blue day. Beam radiation can be quite powerful, and is also the primary radiation source for equipment in Outer Space.

The second type of radiation we have is called diffuse radiation. As the name implies, this radiation is scattered in all directions. It is the primary source of radiation on a cloudy day, or when one is sitting in the shade. Diffuse radiation is not as powerful, and therefore one should not plan on running a photovoltaic system with diffuse radiation alone.

In order to use photovoltaics wisely, one should be in an area abundant with solar energy. Deserts are obvious candidates, in addition to semi-arid and tropical climates. Northern and coastal climates are tougher decisions due to extensive cloud cover, fog patterns, and rains in the winter. Each case should be considered respectively, however, as not all coastal climates are the same.

Photovoltaic panels come in a variety of sizes, voltages, and constructions. They can be wired in series or parallel to meet your system's needs. 12 volt and 24 volt configurations are common, while 48 volts and greater are used for heavy duty installations. Most photovoltaics in production are about 12% efficient. This may not seem like much, but keep in mind that the cost of solar energy is zero, and they will have typical service lives of 25 years.

Converting solar energy with photovoltaics can be a costly investment. If properly sized and selected, however, this investment will pay itself over time. Anywhere from 5 to 10 years payback is a possibility. New types of panels are under development and may be released into the solar energy market in years to come. Some of these panels are geared to lower cost, while others are geared toward increased efficiency.

Using photovoltaics to convert solar energy can be a complicated decision. One must consider the cost of local Utility's rate of electricity, and know the solar energy data for their location. In some cases, as with distant properties and transmission cables, the decision can be easy. But in most cases, an investigation of the payback period will be necessary to know if one is making a cost effective decision. In times of uncertainty and surging fuel costs, the simple piece of mind of energy independent technologies may be well worth the effort.

About the Author

Walter Hull is a mechanical engineer with expertise in solar power systems. For a limited time you can get his free guide to solar power from your own land.

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