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How is light affected by glass sheets?

  1. May 4, 2013 #1
    I was thinking of doing an experiment that looked at how the power produced by solar cell is affected by the number of glass sheets placed between the solar cell and the glass sheets.

    However Im not sure what effect will glass have on light if any? can anyone tell me what effect glass has on light...

    thanks in advanced
     
  2. jcsd
  3. May 4, 2013 #2

    mfb

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    It blocks some frequencies nearly completely, reduces the intensity of other frequencies and reflects a part of the incoming light.

    The same is true for all other materials. Glass as it is used in windows is produced to let most of the visible light through, of course.
     
  4. May 5, 2013 #3
    But will the power of light change if i pass it throught normal glass(used in windows)?
     
  5. May 5, 2013 #4

    mfb

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    It will change a bit, sure.
    I would expect that the total power (=UV, visible light, infrared and minor other contributions) changes more than the reaction of the solar cell (mainly visible light and near infrared).
     
  6. May 5, 2013 #5

    Redbelly98

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    A single glass sheet will reflect about 7 or 8% of the incoming light, so you can expect that much reduction in solar cell power.
     
  7. May 6, 2013 #6
  8. May 6, 2013 #7
    Is this for any sheet of glass or will its width change the amount of light reflected?
     
  9. May 7, 2013 #8

    mfb

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    Reflection mainly happens at the surface, therefore it is independent of the thickness (as long as it is much thicker than the wavelength of light). Absorption depends on the thickness.
     
  10. May 7, 2013 #9

    sophiecentaur

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    A digital camera* would give you a good idea about the absorption of layers of glass. Use a picture of a white card with half covered and the other half uncovered and compare the RGB values on a photo editing program. It would tell you the relative absorption at long, medium and short optical wavelengths too.
    *It would be best to turn off the auto exposure but it wouldn't be too much of a problem as long as you keep your lighting levels constant and make sure that the RGB values are all below 255 (limiting value). If you're getting really smart about it, it might be an idea to keep an eye on the colour balance congtrol and switch it away from 'auto'.
     
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