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? about magnifying lens/parabolic mirrors steam turbine electric generator

  1. Aug 22, 2011 #1
    Ok here's an idea that isn't a perpetual motion machine (it's no more perpetual than solar cells):

    Using a big magnifying lens or parabolic mirrors, what are the formulas when either of them are used to evaporate water into water vapor steam to move a turbine to power an electric generator?
     
  2. jcsd
  3. Aug 22, 2011 #2

    russ_watters

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  4. Aug 22, 2011 #3

    sophiecentaur

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    To get an idea of the upper limit to the power that such a device could transfer, each metre square of collecting area would capture 1kW of solar power. If you could focus the radiation to produce a nice high temperature then you could perhaps think of getting a small fraction of that in mechanical power. I have a feeling that PV cells would do better; heat engines are not the best way of transferring energy if there is alternative.
     
  5. Aug 22, 2011 #4

    Drakkith

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    Sohpie, do you know what the cost comparison is between a solar panel array and a solar heating generator producing equal power?
     
  6. Aug 22, 2011 #5

    sophiecentaur

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    Heating is cheap but a heat engine is not.
    And the feed in tarif is good.
     
  7. Aug 22, 2011 #6

    Drakkith

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    Feed in tarif?
     
  8. Aug 23, 2011 #7

    sophiecentaur

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    An 'in joke'. The UK government makes the electricity supply companies pay a laughably high rate for small scale feeds to the National Grid.
     
  9. Aug 23, 2011 #8

    Drakkith

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    I think the power company here does the same thing to people who want to tie their own power into the grid as well. I looked into it and it turned out that I would be paying more just in fees than I would make up for by adding enough solar power to cover 50% of my average power use.
     
  10. Aug 23, 2011 #9

    sophiecentaur

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    In the south UK, if you have no shadows, then you are very much in profit over several years - if the governmen its word.t keep
     
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