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Interessant novetat panells solars (Read 5617 times)

Interessant novetat panells solars
27.05.2008 a les 11:56:26
esocid writes "Researchers at TU Delft (Netherlands) and the FOM (Foundation for Fundamental Research on Matter) have found irrefutable proof that the so-called avalanche effect by electrons occurs in specific semiconducting crystals of nanometer dimensions. This physical effect could pave the way for cheap, high-output solar cells. Solar cells currently have relatively low output, typically 15%, and high manufacturing costs. One possible improvement could derive from a new type of solar cell made of semiconducting nanocrystals and could theoretically lead to a maximum output of 44%, with the added benefit of reducing manufacturing costs. In conventional solar cells, one photon can release precisely one electron. However, in some semiconducting nanocrystals, one photon can release two or three electrons, hence the term 'avalanche effect.' This effect was first measured by researchers at the Los Alamos National Laboratories in 2004, and since then the scientific world had raised doubts about the value of these measurements. This current research does in fact demonstrate that the avalanche effect can occur."
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panells solars barats!
Reply #1 - 28.05.2008 a les 16:41:06
Panells solars barats!

Es bo saber que s'esta començan ta treballar en aquestes direccions.
Pujar de un rendiment del 15% al 44% significa que d'on abans treies 1 kw ara en treus 4 kw!!
Mireu també aquesta noticia: No te a veure amb eficiencia dels panells, sinó un sistema que abarateix enormement el cost de producció.....

La noticia:
adjunto un estracte:

Imagine a solar panel without the panel. Just a coating, thin as a layer of paint, that takes light and converts it to electricity. From there, you can picture roof shingles with solar cells built inside and window coatings that seem to suck power from the air. Consider solar-powered buildings stretching not just across sunny Southern California, but through China and India and Kenya as well, because even in those countries, going solar will be cheaper than burning coal. That’s the promise of thin-film solar cells: solar power that’s ubiquitous because it’s cheap. The basic technology has been around for decades, but this year, Silicon Valley–based Nanosolar created the manufacturing technology that could make that promise a reality.

The company produces its PowerSheet solar cells with printing-press-style machines that set down a layer of solar-absorbing nano-ink onto metal sheets as thin as aluminum foil, so the panels can be made for about a tenth of what current panels cost and at a rate of several hundred feet per minute. With backing from Google’s founders and $20 million from the U.S. Department of Energy, Nanosolar’s first commercial cells rolled off the presses this year.

Cost has always been one of solar’s biggest problems. Traditional solar cells require silicon, and silicon is an expensive commodity (exacerbated currently by a global silicon shortage). What’s more, says Peter Harrop, chairman of electronics consulting firm IDTechEx, “it has to be put on glass, so it’s heavy, dangerous, expensive to ship and expensive to install because it has to be mounted.” And up to 70 percent of the silicon gets wasted in the manufacturing process. That means even the cheapest solar panels cost about $3 per watt of energy they go on to produce. To compete with coal, that figure has to shrink to just $1 per watt.

Nanosolar’s cells use no silicon, and the company’s manufacturing process allows it to create cells that are as efficient as most commercial cells for as little as 30 cents a watt. “You’re talking about printing rolls of the stuff—printing it on the roofs of 18-wheeler trailers, printing it on garages, printing it wherever you want it,” says Dan Kammen, founding director of the Renewable and Appropriate Energy Laboratory at the University of California at Berkeley. “It really is quite a big deal in terms of altering the way we think about solar and in inherently altering the economics of solar.”

In San Jose, Nanosolar has built what will soon be the world’s largest solar-panel manufacturing facility. CEO Martin Roscheisen claims that once full production starts early next year, it will create 430 megawatts’ worth of solar cells a year—more than the combined total of every other solar plant in the U.S. The first 100,000 cells will be shipped to Europe, where a consortium will be building a 1.4-megawatt power plant next year.

Right now, the biggest question for Nanosolar is not if its products can work, but rather if it can make enough of them. California, for instance, recently launched the Million Solar Roofs initiative, which will provide tax breaks and rebates to encourage the installation of 100,000 solar roofs per year, every year, for 10 consecutive years (the state currently has 30,000 solar roofs). The company is ready for the solar boom. “Most important,” Harrop says, “Nanosolar is putting down factories instead of blathering to the press and doing endless experiments. These guys are getting on with it, and that is impressive.”

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Re: Interessant novetat
Reply #2 - 12.07.2008 a les 21:20:50
Un nou camí per a augmentar l'eficiència de les cel·les solars:
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Re: Interessant novetat panells solars
Reply #3 - 15.07.2008 a les 09:01:51
Pel que veig en la pàgina web, no es tracta de una millora tecnològica de les plaques solars, sinó d'una manera més inteligent de optimitzar-ne la eficiència, amb un concentrador de llum molt especial.

La llum es absorbida dins d'un vidre per una làmina orgànica i és rebotada en baixa freqüència dins aquesta làmina fins els laterals. Queda atrapada per l'anomenat efecte hivernacle: les ones de baixa freqüència no poden travessar els vidres. en els laterals es troben les plaques solars, que reben una quantitat maximitzada d'energia. per tnat, amb una mínima despesa en construcció de plaques solars, tens un rendiment semblant.

he dye-based organic solar concentrator functions without the use of tracking or cooling systems, greatly reducing the overall cost compared to other concentrator technologies. Dye molecules coated on glass absorb sunlight, and re-emit it at a different wavelengths. The light is trapped and transported within the glass until it is captured by solar cells at the edge. Some light passes through the concentrator and can be absorbed by lower voltage solar cells underneath. Alternatively, the partially transmissive concentrator can function as a window.
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