House heating with solar energy
Natural resources that we use every day, such as coal and oil, are gradually ending. The alternative for them is practically inexhaustible, solar energy.
Its use in the close future, may become increasingly common due to lower costs and possible funding.
As reported by Reuters, in 2010 the power that comes from solar installations grew by 120%. In the development of photovoltaic (an area which deals with the conversion of sunlight into electricity) still leads Europe, but in the top ten countries, using solar energy were also China and Japan.
In 2007, project “Desertec” was established, which envisages the construction of solar power plants in the Sahara, and by 2050 is to meet up to 15% of European electricity demand.
But what if we want to live economically and ecologically now?
Solar panels could be the solution to this problem . The principle is simple. The sun heats the absorber (which is solar, or photovoltaic cells in series), which absorbs sunlight and converts it into heat.
Then, heating fluid which flows through the collector is warmed up from the absorber. Most commonly, anti-freeze fluids, such as glycol is used.
When the temperature of the fluid in the collectors is higher than the water in the tank, the driver turns on the pump. Hot fluid is pumped to the coil located in the tank and gives warm to water. Next, it is pumped back into the solar panel for re-heating.
Companies offer two basic types of solar collectors - flat and vacuum tubes.
Mainly due to its price, the most popular is the flat-plate collector. Its drawback is the slightly lower energy efficiency and faster heat loss than in the pipe collector.
In flat collector there is absorber of solar radiation combined with copper pipes, in which working agent (liquid) goes. Absorber plate is made of steel, copper, aluminum or plastic, coated with a thin layer, increasing efficient absorption of solar radiation.
From the outside, the collector is secured by tempered glass, teflon or transparent plastic, protecting against weather conditions. In addition, the glass stops the radiation inside the collector, resulting in higher temperature heating fluid. From the bottom, collector is protected by a layer of thermal insulation that prevents heat transfer to the outside.
Flat-plate collectors can be used all year round, but their greatest effectiveness is in the period from April to September.
More efficient, but also more expensive are vacuum tube collectors, which, thanks to more technologically advanced glass tubes are very effective. They use both direct and diffuse radiation, that is theone that flows through a thin layer of clouds. Thanks to that collector works even on cloudy days and in the winter.
Solar collectors can be installed both on the roof, and on the ground - on a stand. However, to obtain the best results, remember that solar panels should be turned to the south and, of course, be in place free of shadow.