The rapid development of solar technology
Britta Wagner
It began in 1954 with a discovery in a U.S. lab - then its longevity surprised at all: Today is the day on many solar cell roof tops. In Kassel, advise researchers on the future of technology. heute.de gives an overview.
The first silicon mineral solar cell was only two square inches in size and could power a radio. At the beginning of the solar energy was relatively expensive: the cost of one watt of power now are in one Euro - earlier it was a hundred times as much. Therefore it was first used in high-tech field of space in 1958 launched the first satellite with solar cells, sending signals for six years.
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Storm clouds on a solar system.
* Solar companies struggling with storm clouds
The cost decreases
Not until the oil crisis on the use of the earth was interesting. Gradually solar power competitive in Germany. "For the year 2012 is the grid-parity achieved," Bruno Burger says the Freiburg Fraunhofer Institute for Solar Energy Systems, "Then the producer prices are for solar power on the price level of the normal household current of approximately 25 cents per kWh." Its estimates to decrease further the cost of solar energy reaches the end of the decade, the level of the cheaper industrial electricity rates below 10 cents per kWh.
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ISES Solar World Congress 2011
On the world's largest scientific congress on solar energy and architecture around 700 scientists advise on the future of energy supply. Even for companies in the solar industry is a major event in the world congress.
"Reason is the cost of deterioration of the modules, as with any semiconductor technology. In the computer field is very similar," says Burger. The solar industry has now stand at the "Solar World Congress" swapped in Kassel on progress. She now works at the third Generation of solar cells.
Copied from the plant
The classical silicon cell is still over 90 percent market share. The substance may be the second most common element on earth. But to be produced from silica sand as pure silicon crystals, is cumbersome. Therefore, researchers and manufacturers try to use less raw materials by implementing lean manufacturing principles. One approach is the thin-film technology - silicon on a base made of glass, metal or plastic.
The latest development comes not from silicon: Here the light to convert organic dyes such as the photosynthesis of plants into energy. The thin and cheaper, for example, modules can be used in clothing. However, their lifetime is very short.
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Kinderfußabdrücke.
* With the sun can save electricity each
Light through lenses bundled
The biggest drawback of the new technique is its lower power. "There is always a compromise between cost and efficiency," says Burger. While the first silicon cell had an efficiency between four and six percent, it has now reached with the standard solar cell industry in the 20-percent mark, cells obtained from the laboratory even higher values. The efficiency of thin-film and organic solar cells, however, is still in single digits.
But the development is progressing rapidly. An example is the concentrator technology, in which the modules track the sun and the incident light is focused by lenses. Several layers of solar cells use different wavelengths of light, and add the yield. The technology should be used especially in sunny regions.
More reliable than solar wind
But even in Germany, the sun is already bearing its share in the power supply. Burgers evaluations show that solar energy can cover the midday peak consumption. Here, the sun turned out to be more reliable than the wind - even this summer. "That surprised even the experts that are seen to offset the fluctuations in the weather over the entire area of Germany," says Burger.
