12volt to 24volt solar panels...wiring ???

Discussion in 'Alternative Energy' started by greg273, Jul 6, 2006.

  1. greg273

    greg273 Well-Known Member

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    I have one EC-102 PV panel on my roof, wired with 10-2 romex to the charge controller. Its feeding a small batter bank, and an el-cheapo harbor freight 600W inverter. This is basically my temporary 'learning' set-up, with just enough power for a few lights, some TV and radio, and thats about it.
    I'm putting a second panel up soon, same type, but this combined output will go to the 'real' power center, with DR2424 inverter, 175A DC disconnect and all that good stuff.
    My question is, how to get 24volts from two 12volt panels? There are some diagrams on the back of the panels, but I cant figure them out. It seems to imply that the output of these panels can be EITHER 12 or 24volts. Does this mean I have the choice to wire them in series at 12 or parallel at 24?
    Please help this confused newbie out!
    Thanks, Greg
     
  2. wy_white_wolf

    wy_white_wolf Just howling at the moon

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    2 panels wired in series would be 24 volts at the rated amps.

    2 panels wired in parallel would be 12 volts at twice the rated amps.

    By the spec sheet that I found here http://www.solarpanelstore.com/pdf/ec-100.pdf they are 12 volt so you need to wire them in series for 24 operation

    Ain't solar fun!
     

  3. Fire-Man

    Fire-Man Well-Known Member Supporter

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    Yea---What White Wolf Said, but don't forget to rewire your batteries to 24volt too! Randy
     
  4. greg273

    greg273 Well-Known Member

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    OK, in series then , but could someone spell that out for me a little bit? (ie, POSITVE from panel 1 to ?????....) Like I said, newbie. Only by following a strict diagram was I able to hook 4 batteries (6volt) in series-parallel for my 12volt inverter.
    Thanks ! And yeah, solar is fun! Its great to think that while I'm away at work, the sun is charging my batteries for me!

    greg
     
  5. Guy_Incognito

    Guy_Incognito Well-Known Member

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    In series:
    Negative of one panel as earth.
    Positive of that panel hooked to the negative of the next panel
    Positive of the next panel as your "New" postive to the rest of the system.

    That will give twice the voltage at the same amperage.

    In parallel:
    Positive to Positive
    Negative to Negative

    Gives twice the amperage at the same voltage.

    If the rest of your system can be adapted, go higher in voltage when putting more panels in - the power loss in wiring runs will be reduced. If you have skimpy / long wiring and double the panel current, you might lose a bit more across your wiring.
     
  6. Fire-Man

    Fire-Man Well-Known Member Supporter

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    Greg, just treat the panels like they were batteries---hook the positive of one 12 volt panel to the negative of another 12 volt panel------then using the other positive and negative you will get 24 volts, then use 4-6 volt batteries hooked in series to get your 24 volt battery bank. Have fun!! Randy
     
  7. mightybooboo

    mightybooboo Well-Known Member

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  8. greg273

    greg273 Well-Known Member

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    Thank you all for the great responses! Exactly the kind of help I was looking for!
     
  9. Jim-mi

    Jim-mi Well-Known Member

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    It would also be a good idea to have a meter so that you can check your self..........and save yourself some grief from improper hook ups.