Array stopped producing power - need some guidance

I have a solar array consisting of 14 Kyocera KD180 GX-LP 180 Watt panels and a Sunny Boy 2100U inverter, this system is about 13 years old.  The array stopped producing power over the winter and now that the weather has improved here in Wisconsin I got up on the roof over the weekend to troubleshoot.  I had two panels that were in pretty bad shape (frame pulled away from the glass due to snow load) so I assumed one of these was the problem.

I removed these two panels from the string and it started sending power to the grid!  I plugged back in one of the potentially bad panels and everything worked as expected until the following day.  The next day I saw no output from the inverter.  I have now removed both suspect panels but have not been able to get power flowing again since that first day.  With the 12 panels currently connected, it shows 0-3 watts and voltage of 315V-345V.  The inverter does not show any errors or warnings.  Does this indicate that I may have a different bad panel in the string?  Any ideas on why it worked fine that first day and then didn’t come back online the following day?  I’m stumped and would very much appreciate some guidance to get back online.  Thanks in advance!


  • Dave AngeliniDave Angelini Solar Expert Posts: 6,026 ✭✭✭✭✭
    An intermittent !  Probably the hardest thing to troubleshoot. What I have done in the past, and I did not have to go on a roof, is to separate each module, test voc and isc. Usually you will find a oddball. Check wiring

    With that kind of damage and at that age, I would also consider just replacing the whole system.
    "we go where power lines don't" Sierra Mountains near Mariposa/Yosemite CA
    E-mail [email protected]

  • WISolarMonkeyWISolarMonkey Registered Users Posts: 2
    Thank you.  If it were easier to just pull each panel and test individually, I think I would totally go that route.  I am also seriously considering replacing the entire system since it would be relatively cheap to do since the wiring and racking can be reused.  Thanks again for your insight.
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