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Science Forum

Science Forum

  1. Standard member sonhouse
    Fast and Curious
    12 Nov '13 03:04
    No silver conductors, change to copper, but that brings on the infamous copper diffusion problems they licked. That is only the first technique used by this company to increase efficiency to 21% and low cost manufacturing at the same time:

    http://phys.org/news/2013-11-solar-cell-efficient-costly.html
  2. 13 Nov '13 10:53 / 2 edits
    Here is yet another link indicating we soon could be having both cheaper and more efficient solar cells:

    http://phys.org/news/2013-11-simpler-cheaper-solar-cells.html
    “...
    ...Previously, researchers were able to get mesostructured perovskite cells to 15% efficiency, using a perovskite compound with a diffusion length of around 100 nanometres (nm). But by adding chloride ions to the mix, Henry's group achieved diffusion lengths over 1000nm. These improved cells can reach 15% efficiency without the need for complex structures, making them cheaper and easier to produce.

    ...We could well be seeing perovskite cells with efficiencies of 20-30% within the next few years,
    ….”

    -All these links we have been getting recently indicating this sound very promising don't they!
  3. 13 Nov '13 11:16
    Originally posted by humy
    -All these links we have been getting recently indicating this sound very promising don't they!
    But are all the different ideas compatible with each other or are they competing ideas?
    Also are they all patented and thus may be restricted to particular manufacturers (with different manufacturers for each idea).

    And when can we have them here in Africa?
  4. Standard member sonhouse
    Fast and Curious
    13 Nov '13 11:27
    Originally posted by twhitehead
    But are all the different ideas compatible with each other or are they competing ideas?
    Also are they all patented and thus may be restricted to particular manufacturers (with different manufacturers for each idea).

    And when can we have them here in Africa?
    Well, here is another technology that is going to make cheap PV cells:

    http://phys.org/news/2013-11-simpler-cheaper-solar-cells.html

    Already up to 15% efficient, looking for 20 to 30% in a few years for basically the same price.

    So there will be cells in Africa too. I keep waiting for them here in the US!

    I can't afford 20,000 dollars for a solar system.
  5. 13 Nov '13 11:38 / 2 edits
    Originally posted by twhitehead
    But are all the different ideas compatible with each other or are they competing ideas?
    Also are they all patented and thus may be restricted to particular manufacturers (with different manufacturers for each idea).

    And when can we have them here in Africa?
    But are all the different ideas compatible with each other or are they competing ideas?

    I think they are a mixture of both. The important thing I think is that at least one of those ideas, if not some complementary combination of those ideas, pans out and pans out soon! I don't think it can come too soon -the world needs this as soon as possible.
  6. 17 Nov '13 19:57
    Here is a quantum effect that could greatly boost energy efficiency of solar cells:

    http://phys.org/news/2013-11-solar-power.html
    “.....
    Solar cells offer the opportunity to harvest abundant, renewable energy. Although the highest energy light occurs in the ultraviolet and visible spectrum, most solar energy is in the infrared. There is a trade-off in harvesting this light, so that solar cells are efficient in the infrared but waste much of the energy available from the more energetic photons in the visible part of the spectrum.

    When a photon is absorbed it creates a single electronic excitation that is then separated into an electron and a positively charged hole, irrespective of the light energy. One way to improve efficiency is to split energy available from visible photons into two, which leads to a doubling of the current in the solar cell.
    Researchers in Cambridge and Mons have investigated the process in which the initial electronic excitation can split into a pair of half-energy excitations. This can happen in certain organic molecules when the quantum mechanical effect of electron spin sets the initial spin 'singlet' state to be double the energy of the alternative spin 'triplet' arrangement....

    The study, published today in the journal Nature Chemistry, shows that this process of singlet fission to pairs of triplets depends very sensitively on the interactions between molecules. By studying this process when the molecules are in solution it is possible to control when this process is switched on.
    When the material is very dilute, the distance between molecules is large and singlet fission does not occur. When the solution is concentrated, collisions between molecules become more frequent. The researchers find that the fission process happens as soon as just two of these molecules are in contact, and remarkably, that singlet fission is then completely efficient—so that every photon produces two triplets.

    ...”
  7. 17 Nov '13 20:05
    Originally posted by sonhouse
    I keep waiting for them here in the US!

    I can't afford 20,000 dollars for a solar system.
    When did you last check. I saw charts showing a price drop of over 50% in the last 2 years. However that may be for the manufacturing cost of the panels. A full solar system includes batteries transformers and rectifiers etc and installation labour so maybe the full cost hasn't come down that much.