Spots on cells

I made an order from a manufactorer and more then half of the panels had four small brown spots on each cell and it looks almost exactly the same on every panel that have this. The spots are very small and brownish, and they sit at almost exactly the same places on all cells and on all these panels, just slightly diagonal from the spot on the cell above and under. does any one know what this can be?


  • Dave AngeliniDave Angelini Solar Expert Posts: 6,131 ✭✭✭✭✭
    If you ask the company who made them (???) they will get an engineer to tell you that there is not a problem and they will fully meet spec. You just have to hope they are in business and be able to monitor each panel. That is the way it works these days. It sucks because if you have to sell them someday, it will not be easy!
    "we go where power lines don't" Sierra Mountains near Mariposa/Yosemite CA
    E-mail [email protected]

  • littleharbor2littleharbor2 Solar Expert Posts: 1,692 ✭✭✭✭
    I'm pretty sure it's just part of the automated manufacturing process. These marks are very common on many polycrystalline solar panels.

    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.

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