High efficiency solar

Discussion in 'Energy' started by Old Rocks, Jun 26, 2010.

  1. Old Rocks
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    Old Rocks Diamond Member

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    Real research that will lead to very cheap solar power.

    Quantum dots for highly efficient solar cells - physicsworld.com

    The efficiency of solar cells could be increased to more than 60% from the current limit of just 30% according to new work by scientists in Minneapolis and Texas. The new work involves capturing the higher-energy sunlight that is normally lost as heat in conventional devices using semiconductor nanocrystals, or quantum dots.

    The maximum efficiency of conventional solar cells made from silicon-based semiconductors is limited by theory to around 31% – and the best performing affordable commercial devices are less than 20% efficient. This is because in typical devices, photons with energies above the semiconductor's bandgap generate "hot" charge carriers (electrons and holes) that quickly cool to the band edges in a matter of just picoseconds, releasing phonons (vibrations of the crystal lattice, or heat). If the energy of these hot electrons could be captured before it is converted into wasted heat, solar-to-electric power-conversion efficiencies could be increased to as high as 66%, say scientists.
     
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  2. Quantum Windbag
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    Quantum Windbag Gold Member

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    From your link.


    That means they aren't even close to making this work, and the first high cost prototypes are probably going to be less efficient than current solar tech.
     
  3. Old Rocks
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    Old Rocks Diamond Member

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    Technology Review: Silicon Nanocrystals for Superefficient Solar Cells

    Silicon Nanocrystals for Superefficient Solar Cells
    Research shows that silicon can wring two electrons from each photon of incoming light.

    By Kevin Bullis
    Wednesday, August 15, 2007


    A typical solar cell generates only one electron per photon of incoming sunlight. Some exotic materials are thought to produce multiple electrons per photon, but for the first time, the same effect has been seen in silicon. Researchers at the National Renewable Energy Laboratory (NREL), in Golden, CO, showed that silicon nanocrystals can produce two or three electrons per photon of high-energy sunlight. The effect, they say, could lead to a new type of solar cell that is both cheap and more than twice as efficient as today's typical photovoltaics.


    Souped-up silicon: A micrograph of a seven-nanometer chunk of crystalline silicon, called a nanocrystal or quantum dot. Such structures could dramatically increase the efficiency of solar cells.
    Credit: Arthur Nozik, National Renewable Energy Laboratory
    As in earlier work with other materials, the extra electrons come from photons of blue and ultraviolet light, which have much more energy than those from the rest of the solar spectrum, especially red and infrared light. In most solar cells, the extra energy in blue and ultraviolet light is wasted as heat. But the small size of nanoscale crystals, also called quantum dots, leads to novel quantum-mechanical effects that convert this energy into electrons instead.
     
  4. Old Rocks
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    Old Rocks Diamond Member

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    High Volume Production of Quantum Dots for Solar Cells and Other Applications

    Solterra Renewable Technologies will be producing and distributing a Thin Film Quantum Dot PV Solar Cell, which is differentiated from other traditional PV cells by a unique technology that can result in lower cost, higher efficiency, and broader spectral performance. Solterra's Quantum Dot Solar Cell can achieve a dramatically lower manufacturing cost per watt in part, because we can manufacture our own quantum dots using a patent pending, revolutionary process that results in the production of extremely desirable, high quality tetrapod quantum dots at a cost savings in excess of 95%.
     
  5. KissMy
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    KissMy Free Breast Exam

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    I have heard all this before 6 years ago but it was about Quantum Dots Solar paint that could be painted onto car bodies & generate 5 times more power than current solar panels.

    Bottom line is currently anything that says it operates with quantum anything is a money scamming hoax just like the over-unity generator. The reusable Quantum water disk that you put in your washer instead of soap was one huge scam that suckered millions. Some day when they perfect the nanobot usage on a large scale then they may be able to use them to construct some quantum dots. I bet that will be at least 15 years from now.
     
  6. Old Rocks
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    Old Rocks Diamond Member

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    tunnel diode
     
  7. KissMy
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    KissMy Free Breast Exam

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    The EU’s Solar Science Fiction
     
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  8. editec
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    editec Mr. Forgot-it-All

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    15 years from now beats never.

    I believe that the current manifestation of our energy problems will largely be solved in our lifetimes, too.

    Let us assume it will be solved and that we will migrate in a generation or so away from hydrocarbon energy and the resulting pollution problems they entrail.

    We are still going to have the problem of too many men polluting their own nest.

    In fact, having cheap and abundant energy that is not spewing out CO2 will likely increase this over population problem.

    As the rest of humankind -- 2 billion of which are now living at a subsistance level -- start competing for resources that today they are not in the market for today, new problems will manifest that probably aren't immediately apparent to us now.


    I don't know what the next strategic resource crises will be, (I suspect we're going to have a few of them in our lifetimes) but I suspect H2O is already on that list, for example.


    Bottom line?

    We have too many people to sustain the quality of life that we in the industrialized world have come to expect.

    I believe that sooner, rather than later, mankind is collectively going to have to do something about the over population.

    Just as the economists remind us that there is NO FREE LUNCH, so too we must acknowledge that the environment (which is really the economy in the raw) is telling us the EXACT SAME THING.
     
  9. KissMy
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    So lets pass healthcare to allow more births & fewer deaths?
     
  10. Old Rocks
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    Old Rocks Diamond Member

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    Universal Health Care has nothing to do with increasing population. Many of the industrial nations that have UHC have a negative population growth.
     

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