Buying a used solar panel ?

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bc buck
bc buck Registered Users Posts: 59 ✭✭
Talked to a guy wanting to sell a Sharp 235w panel for a $100. What should I look for other than cracks in glass and voltage output.

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  • mcgivor
    mcgivor Solar Expert Posts: 3,854 ✭✭✭✭✭✭
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    If I were to consider a used panel these are the things I would check, open circuit voltage and short circuit current and determine if there's a use for it, for example if it a 60 cell panel, it cannot be used with a PWM controller. The glass won't crack, it will only turn to cubes if broken, my opinion would be to consider new panels over used, you might be able to get close to that price with new, sometimes buying used is a false economy.
    1500W, 6× Schutten 250W Poly panels , Schneider MPPT 60 150 CC, Schneider SW 2524 inverter, 400Ah LFP 24V nominal battery with Battery Bodyguard BMS 
    Second system 1890W  3 × 300W No name brand poly, 3×330 Sunsolar Poly panels, Morningstar TS 60 PWM controller, no name 2000W inverter 400Ah LFP 24V nominal battery with Daly BMS, used for water pumping and day time air conditioning.  
    5Kw Yanmar clone single cylinder air cooled diesel generator for rare emergency charging and welding.
  • littleharbor2
    littleharbor2 Solar Expert Posts: 2,046 ✭✭✭✭✭
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    Damage to the back sheet.  Any discoloration in the cells and cell interconnect tabbing. Most solar panels (including Sharp) use tempered glass and when broken will shatter into a "million pieces" so if not shattered the glass should be fine.


    Voltage output isn't a full indication of a working panel. You want to see the short circuit amperage and is so equipped  test the panel under load.

    2.1 Kw Suntech 175 mono, Classic 200, Trace SW 4024 ( 15 years old  but brand new out of sealed factory box Jan. 2015), Bogart Tri-metric,  460 Ah. 24 volt LiFePo4 battery bank. Plenty of Baja Sea of Cortez sunshine.

  • Photowhit
    Photowhit Solar Expert Posts: 6,003 ✭✭✭✭✭
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    bc buck said:
    Talked to a guy wanting to sell a Sharp 235w panel for a $100. What should I look for other than cracks in glass and voltage output.

    I think you had some Kyrocera 12 volt panels? This would not be compatible with those.

    Not really a great price, other than you don't have to worry about shipping. We're seeing prices for new in this neighborhood.
    Home system 4000 watt (Evergreen) array standing, with 2 Midnite Classic Lites,  Midnite E-panel, Magnum MS4024, Prosine 1800(now backup) and Exeltech 1100(former backup...lol), 660 ah 24v Forklift battery(now 10 years old). Off grid for 20 years (if I include 8 months on a bicycle).
    - Assorted other systems, pieces and to many panels in the closet to not do more projects.
  • bc buck
    bc buck Registered Users Posts: 59 ✭✭
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    Photowhit said:
    bc buck said:
    Talked to a guy wanting to sell a Sharp 235w panel for a $100. What should I look for other than cracks in glass and voltage output.

    I think you had some Kyrocera 12 volt panels? This would not be compatible with those.

    Not really a great price, other than you don't have to worry about shipping. We're seeing prices for new in this neighborhood.
    Yes, I installed three Kyocera KD145sx-ufs in series. When I replaced my battery bank I increased the AH to 430. Could use a little more watts if I could get a good deal and save on shipping. The Morningstar PS-MPPT-40 said it could be over watt in panels as long as did not go over Voc of 120 DC. The three Kyrocera total Voc=66.9. Was thinking if added Sharp in series 37 Voc would = total Voc of 103.9. Does this sound  like it would work. Thanks
  • Photowhit
    Photowhit Solar Expert Posts: 6,003 ✭✭✭✭✭
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    bc buck said:
    Yes, I installed three Kyocera KD145sx-ufs in series. When I replaced my battery bank I increased the AH to 430. Could use a little more watts if I could get a good deal and save on shipping. The Morningstar PS-MPPT-40 said it could be over watt in panels as long as did not go over Voc of 120 DC. The three Kyrocera total Voc=66.9. Was thinking if added Sharp in series 37 Voc would = total Voc of 103.9. Does this sound  like it would work. Thanks
    They won't work properly on the same charge controller. You would want to put them on separate charge controllers. Other wise in a single string the output would be limited to the amperage of the Kyrocera panels, so you would get less total effective power (wattage) from them.
    Home system 4000 watt (Evergreen) array standing, with 2 Midnite Classic Lites,  Midnite E-panel, Magnum MS4024, Prosine 1800(now backup) and Exeltech 1100(former backup...lol), 660 ah 24v Forklift battery(now 10 years old). Off grid for 20 years (if I include 8 months on a bicycle).
    - Assorted other systems, pieces and to many panels in the closet to not do more projects.
  • bc buck
    bc buck Registered Users Posts: 59 ✭✭
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    Photowhit said:
    bc buck said:
    Yes, I installed three Kyocera KD145sx-ufs in series. When I replaced my battery bank I increased the AH to 430. Could use a little more watts if I could get a good deal and save on shipping. The Morningstar PS-MPPT-40 said it could be over watt in panels as long as did not go over Voc of 120 DC. The three Kyrocera total Voc=66.9. Was thinking if added Sharp in series 37 Voc would = total Voc of 103.9. Does this sound  like it would work. Thanks
    They won't work properly on the same charge controller. You would want to put them on separate charge controllers. Other wise in a single string the output would be limited to the amperage of the Kyrocera panels, so you would get less total effective power (wattage) from them.
    Thanks, il need to start looking around for another Kyrocera 145.