Solar Panels and Solar Energy

Solar energy collectors are simple structures. Their task is to absorb the incident rays of the sun, and to use the energy to heat water. The simplest systems are in those areas of the world where high solar irradiation is present, such as the Mediterranean region, or India.

Tubes are attached to black sheets of metal, and water is passed through them to a tank. The metal sheet, called the absorber, converts the radiant energy into heat and passes it on to the water. The warm water can then be removed from the tank, and at the same time, cold water is supplied into the system to be heated again. More information on DIY Solar Water Heater FAQ.

Unfortunately, such simple systems are not useful in our latitudes, because of the low solar irradiation; here, the black absorber must be replaced by a flat-plate collector. This is a box-shaped device in the middle of which the collector body is installed. Toward the back, it is provided with an insulating layer, so that heat losses are kept down. On the side facing the sun, one or two glass plates are placed in front of the collector. They make it possible for the system to operate more effectively, because less energy is lost by irradiation when the absorber body is heated. Theoretically, a maximum temperature of up to 120 deg can be achieved with these systems; in practice, however, the temperature is kept down to the level of the desired temperature of the warm water, so that the most energy-efficient operating temperature of the system is 60 deg C.

Although it sounds so simple in principle, it is all the more ingenious in its technical realization. The absorber body and the glass tops are not of simple materials, but are selectively coated so that the absorber can absorb as high a proportion as possible of the spectrum of visible light. On the other hand, the coating helps ensure that radiation losses in the infrared range are not too great, which would reduce the degree of effectiveness of the system. Therefore, an additional selective coating ensures that less us emitted in this spectral range. The same applies to the glass plates glass plates: they are supposed to let the incident sunlight in and reflect as little of it as possible back, and ensure that the infrared radiation reflected by the absorber is reflected back again in the direction of the absorber.

All this is state-of-the-art now, and it makes the collectors technically demanding products, but it also costs money to produce. If all you want to do is hear water for the swimming pool in your yard, very simple systems will suffice, even at your latitudes. Unfortunately, the radiation availability throughout the year is not such that it would be possible to meet our hot-water requirements with solar collectors year-round. Systems with the cost side optimized, for example for a four-person household in a detached home, have a collector area of about 6 sq. m. and a tank with around 300 liters of water content, and can produce enough heat for approximately half our annual hot-water needs. The remaining heat must be obtained via a conventional heat system, either a boiler or else an additional electric heater. This system is sold on the market for about Pounds 5000, including assembly. Assuming a life span of twenty years, a private individual can deduct it at a rate of Pounds 250 per year. A CFO could add the lost interest, since he could have put the money in the bank instead of investing it in a solar system. At the same time, there are savings of about 200 cu.m. of natural gas or 200 liters of fuel oil per year, since the solar energy heats the water. Obviously, this system will not yet amortize itself at the energy price of 90 cents per liter of oil, which prevailed in mid-2008. Nevertheless, some one million solar-heating systems have been installed in Germany alone. A good measure of idealism, and also a government subsidy for this new technology, are the reasons for this market situation.

Find out more about DIY solar panels and learn how to build a solar panel today!

Useful information DIY Solar Water Heater FAQ:
http://www.smugbox.com/Build-Solar-Panel/ViewContent?id=2334

Learn how to DIY solar panels:
http://www.prlog.org/10295698-diy-solar-panel-complete-analysis-on-home-solar-power-systems.html