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Energy transfer in solar panels

  1. Sep 1, 2013 #1
    Compound A has an albedo value (visible spectrum) of 0.08, and an emissivity (infrared) of 0.08.
    Compound B has an albedo value of 0.04 and an emissivity of 0.88, in the same spectrums.

    We need to explain why A is more effective at transferring energy to the water flowing behind it, when used as a coating on a solar panel.

    So far, I've determined that (imagining the incident sunlight is, say, 1000W)...

    - B reaches a higher temperature when at thermal equilibirum
    - B reflects 40W, absorbs 960W, and thus emits 960W at thermal equilibirum
    - A reflects 80W, absorbs 920W, and thus emits 920W at thermal equilbirum

    So B is both at a higher temp (and thus has a higher transfer of energy by Newton's law of cooling) and it's also emitting 960W, as opposed to 920W for A.
    So everything seems to be pointing to B as a more effective energy transferrer.
    Where am I going wrong?

    Thanks :)
    Last edited: Sep 1, 2013
  2. jcsd
  3. Sep 1, 2013 #2
    This is falling quickly off the front page so I'm going to be petulent and bump it.
    Didn't post any formulas because alfredo/reflectivity and emissivity are pretty much just ratios.
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