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Photovoltaic Electricity Panels |
Producing electricity at home using photovoltaic panels is not a new concept, and has become increasingly more common in the last few years. It sounds a great thing to do, and indeed it is, but some research and a good project plan is essential before starting off. Photovoltaic electricity panels come in various sizes, from just a few watts of power, to 300 or 400 watts. The power output from a panel is directly proportional to it's area, and so a panel delivering a large amount of electrical power is obviously much larger than for a smaller amount. Each photovoltaic panel is made up of small cells which generate a small amount of electricity - the greater the number of cells, then the more electricity is generated. Unfortunately, one of the great problems associated with PV Panels is the cost, which reflects the manufacturing process plus the raw material, and the natural efficiency of the conversion process. |
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The cells comprising photovoltaic electricity panels are actually a kind of crystal which is 'grown' in the form of a long cylinder, and then cut. Thin slices of the material are connected together, mounted flat on a supporting board and tough glass or resin protects the arrangement. At the rear of the panel there is a junction box with several connections, the configuration depending upon the voltage of the panel. Panels can be purchased commonly for 12, 24 and 48 volts dc. DC stands for 'direct current', which is the same form of electricity as your car battery, or the small cells used to power electrical items at home. Any photovoltaic system used for the home must have a seperate complete control system for converting the electricity to a.c., or alternating current, which is the kind used in the home. The system will also transform the voltage to match the house supply voltage. Unfortunately, solar photocoltaic electricity panels are only about 13% efficient, which means that if 1000 watts of sunshine energy falls onto the panel, only 130 watts of electricity will be generated for you to use. Scientists are constantly working to try and improve this figure, and some gains have been made with panels approaching 20% efficiency, but of course, the cost increases proportionally. One day there may be a breakthrough, which may well be the saving of mankind in the search for cheap energy that isn't destroying the environment. The energy available from the sun varies greatly, depending upon your location, but if we imagine that on average the figure is around 1000 watts per square meter, and the panels only convert 13% of that, then we would need a series of solar panels with a total area of around 8 square meters in order to generate just 1000 watts of photovoltaic electricity, which is quite a low amount. For the moment, perhaps a more interesting use of photovoltaic electricity panels may be the smaller variety used for low-power applications.
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