Bad PV panel??

MarkC
MarkC Solar Expert Posts: 212 ✭✭✭
One cell has a brown area in right side.  This is the only panel that has such a discolored cell.  The panel is part of a string of eight in series.   Has anyone experienced this type of discoloration - and is it a serious issue?  It is a Solar World, Sunmodule 385 panel and is still under warranty.  


3850 watts - 14 - 275SW SolarWorld Panels, 4000 TL-US SMA Sunny Boy Grid tied inverter.  2760 Watts - 8 - 345XL Solar World Panels, 3000 TL-US SMA Sunny Boy GT inverter.   3000 watts SMA/SPS power.  PV "switchable" to MidNite Classic 250ks based charging of Golf cart + spare battery array of 8 - 155 AH 12V Trojans with an  APC SMT3000 - 48 volt DC=>120 Volt AC inverter for emergency off-grid.   Also, "PriUPS" backup generator with APC SURT6000/SURT003  => 192 volt DC/240 volt split phase AC inverter.  

Comments

  • BB.
    BB. Super Moderators, Administrators Posts: 33,431 admin
    Does not look good... But if you can prove "electrically" the panel is failing, you will probably will have an easier time for warranty replacement. Assuming there are no other obvious physical issues (cracked liner in back, obvious signs of water infiltration from bad edge seal, etc. that show a mfg/design defect).

    Best method, use a DC Current Clamp Meter to measure the current in two strings... The "good string" and the questionable string. If the current is significantly different (mine "bad panels" were 50% the current of another "good reference panel"). Example of meters (note that AC current clamp meters cannot measure DC current... And DC current clamp meters are AC+DC current capable).

    https://www.amazon.com/UNI-T-Digital-Current-Capacitance-Multimeter/dp/B0772FYF5M
    https://www.amazon.com/gp/product/B019CY4FB4

    Another quick check... If you have a combiner box with breakers, turn off (or on) one string at a time and see if the questionable panel string has much less current/power than the other "good strings" (under same sun conditions).

    Lastly, disconnect a "good" and "questionable" panel, and measure Voc and Isc for both (under same sun conditions). The numbers should be very close (less than 10% different)--If >50% different, easily bad. If panels are less than 10 Amps Isc, then a typical 10 amp max range meter can be shorted across the panel connections (not ideal). Otherwise, short the panel output and use a DC current clamp meter to make the measurement (Isc).

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • MarkC
    MarkC Solar Expert Posts: 212 ✭✭✭
    I've sent the picture to the warranty group.  I'll see what they say and post.  
    Bill - thanks again for your inputs,
    Mark
    3850 watts - 14 - 275SW SolarWorld Panels, 4000 TL-US SMA Sunny Boy Grid tied inverter.  2760 Watts - 8 - 345XL Solar World Panels, 3000 TL-US SMA Sunny Boy GT inverter.   3000 watts SMA/SPS power.  PV "switchable" to MidNite Classic 250ks based charging of Golf cart + spare battery array of 8 - 155 AH 12V Trojans with an  APC SMT3000 - 48 volt DC=>120 Volt AC inverter for emergency off-grid.   Also, "PriUPS" backup generator with APC SURT6000/SURT003  => 192 volt DC/240 volt split phase AC inverter.  
  • MarkC
    MarkC Solar Expert Posts: 212 ✭✭✭
    No response to any requests made to Solar World warranty emails.  Has anyone had recent success in contacting SW about the SunModule panels? 
    3850 watts - 14 - 275SW SolarWorld Panels, 4000 TL-US SMA Sunny Boy Grid tied inverter.  2760 Watts - 8 - 345XL Solar World Panels, 3000 TL-US SMA Sunny Boy GT inverter.   3000 watts SMA/SPS power.  PV "switchable" to MidNite Classic 250ks based charging of Golf cart + spare battery array of 8 - 155 AH 12V Trojans with an  APC SMT3000 - 48 volt DC=>120 Volt AC inverter for emergency off-grid.   Also, "PriUPS" backup generator with APC SURT6000/SURT003  => 192 volt DC/240 volt split phase AC inverter.  
  • RCinFLA
    RCinFLA Solar Expert Posts: 1,484 ✭✭✭✭
    From the metallization pits it looks like humidity intrusion with corrosion resulting.. Check to make sure there is no scrapes or pricks on backside laminate.  They would chalk that up to likely bad handling during installation or critters scratching backside and probably void warranty.  For a side seal problem you have a better chance but even that can be blamed on install.

    Cell shunt defects don't look like that and unless you have a daily partial shading problem it usually doesn't do too much damage.
  • Ralph Day
    Ralph Day Solar Expert Posts: 1,019 ✭✭✭✭
    Yikes!  Haven't seen the tin man in so long, I thought he'd been blown off Florida in the last hurricane!i  Good to see you back.
  • DanS26
    DanS26 Solar Expert Posts: 264 ✭✭✭
    edited June 2020 #7
    Just buy a replacement panel.....and while you're at it, buy 2 or 3 more and store.....best insurance you can buy.  PV panel warranties are not worth the paper (or electrons) they're written on.
    23.16kW Kyocera panels; 2 Fronius 7.5kW inverters; Nyle hot water; Steffes ETS; Great Lakes RO; Generac 10kW w/ATS, TED Pro System monitoring