Used Solar panel with "Blister" and Brown Patches

bigbrovar
bigbrovar Registered Users Posts: 31 ✭✭
edited May 2017 in Solar Beginners Corner #1
Hi guys. I have two questions.

First I intend to upgrade my off-grid solar setup by addition more panels. I got 2 used 220w panels from online but when they arrived I found that that one of the panel has small opening at the back (see attached) like a some blister. The corresponding surface area in front of the panel also bares mark of defect like a short circuit.

Both panels also had some patches of brown at the top right and left side and bottom of the panels. The brownish of the usually white part of the panel. 

I ran a test on the panels using a multimeter and got good result. IMP for each of the panels (the one with the "wound" and without) was 7.9A . The VOC was 35. This was any 13:30 on a clear sky 38C day.
The panel stickers were out so no way to reference the above figures to manufacturers specs although seller claim them to be made by Lorentz the German solar company.

I attached each of the panels to a pwm charge controller connect to a 40A 12v AGM battery. (This was late afternoon around 15:30) I recorded about 3.4A, 20v) from each panel. I took out an older PV which I have hard for some time has a reference and it too gave similar output.

Here comes my Question:

Can I still use this panels? are they any good and what could be the cause of the brown patch, also I would have imagined that the panel with the "blister" would deliver a significantly lower power compared to the rest but the blister didn't seem to affect it. What could be the reason for this?
Is it something I can ignore or something that would get worse.Used Solar panel with "Blister" and Brown Patches

Comments

  • mmaritz
    mmaritz Registered Users Posts: 15 ✭✭
    If they are producing power then I would use them.  Keep and eye on them but why not ;)
    • Main: Infinisolar 3+ (3kv) 48V Grid-Tied PV=3410w NE facing (8x 330W JASolar, 3x 310W Yingli), + Victron MPPT 150/60 @1240w SW facing (2x 310W Renesola, 2x 330W JASolar), Pylontech US3000, Victron BMV 700, 6 string combiner box with PV isolator switch, subDB for inverter supplied power.
    • Draadkar: Axpert 800w, 24V, 8x 12V - 105ah Leisure Batteries 400ah, PV=480 (2x 240W ElChepo), Victron BMV 702 for laptop, relays backup.
    • ICC for management, automated switch over and monitoring, pushing data to EmonCMS and PVOutput.org (Aloe Ridge Farm).
    • Weather from personal weather station using Weather Display.
  • littleharbor2
    littleharbor2 Solar Expert Posts: 2,036 ✭✭✭✭✭
    edited May 2017 #3
    The brown staining looks like water intrusion. Not good These panels have a short life expectancy with compromised lamination. The burnt cell is clearly a problem. You really need a MPPT controller to connect these 60 cell panels to a 12 volt battery. I'm sure when properly connected the damaged panel will not perform correctly, under load.  Your test with a multimeter was the Isc, not Imp. This is really meaningless without voltage flowing. You need to put a load on this panel when testing it it

    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.

  • bigbrovar
    bigbrovar Registered Users Posts: 31 ✭✭
    The brown staining looks like water intrusion. Not good These panels have a short life expectancy with compromised lamination. The burnt cell is clearly a problem. You really need a MPPT controller to connect these 60 cell panels to a 12 volt battery. I'm sure when properly connected the damaged panel will nor perform correctly, under load.  Your test with a multimeter was the Isc, not Imp. This is really meaningless without voltage flowing. You need to put a load on this panel when testing it it
    Thanks for alot for the explanation. I was wondering if it was possible to fix the compromised lamination problem of the panel. May by adding silicon? 
  • mcgivor
    mcgivor Solar Expert Posts: 3,854 ✭✭✭✭✭✭
    The cell may be compromised, leaving the ballance of cells working, sealing with silicone may prevent water intrusion at very least, the panel as a whole may still have some life left but I would seriously consider a plan for replacement in the future.
    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: 2,036 ✭✭✭✭✭
    If you can remove the aluminum frame on the ends of the panel you might be able to clean and apply some latex, urethane or silicone. You could use these panels for learning about solar but I wouldn't put them in any kind of "mission critical" use. Hopefully you got a really good price on these panels. Personally I wouldn't pay any more than $20.00 a piece for them.

    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.

  • Estragon
    Estragon Registered Users Posts: 4,496 ✭✭✭✭✭
    I'd use epoxy if trying to fix. I also wouldn't mount to anything flammable!
    Off-grid.  
    Main daytime system ~4kw panels into 2xMNClassic150 370ah 48v bank 2xOutback 3548 inverter 120v + 240v autotransformer
    Night system ~1kw panels into 1xMNClassic150 700ah 12v bank morningstar 300w inverter
  • Photowhit
    Photowhit Solar Expert Posts: 6,002 ✭✭✭✭✭
    edited May 2017 #8
    The front side last photo, discoloration and trails of solder(?) appears to be a condition known as Snail trails, I suspect the brown 'thing' was a cause and the trails an effect, Here's some more information about it;

    http://ac.els-cdn.com/S1876610213013957/1-s2.0-S1876610213013957-main.pdf?_tid=ea1b10fe-401c-11e7-bcf3-00000aacb360&acdnat=1495588038_daa3243f5d7e95712fb67ecbc72cc17b

    I've also heard of the 'water marks' discoloration called this, but I usually think of that as a loss of vacuum seal. I don't know the long term effects of the snail trails, the loss of seal or lamination, might cause problems with oxidation. I have some very old monocrystalline panels (1980) that I tore the backing material back in @2002, I used 'tool dip' or 'liquid electrical tape' to cover the holes. they are still functional panels today, even though they show some oxidation.

    I have used the same solution when I purchased some warehouse damaged panels, and they have not shown any loss of lamination visible on the front side, but they had an addition protection sheet between the backing and the cells. (Suntech)
    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.
  • Lumisol
    Lumisol Registered Users Posts: 374 ✭✭✭
    Flexseal
  • mike95490
    mike95490 Solar Expert Posts: 9,583 ✭✭✭✭✭
    looks like lightning damage, from a stray streamer,  What else melts a hole in aluminum ?
    Powerfab top of pole PV mount | Listeroid 6/1 w/st5 gen head | XW6048 inverter/chgr | Iota 48V/15A charger | Morningstar 60A MPPT | 48V, 800A NiFe Battery (in series)| 15, Evergreen 205w "12V" PV array on pole | Midnight ePanel | Grundfos 10 SO5-9 with 3 wire Franklin Electric motor (1/2hp 240V 1ph ) on a timer for 3 hr noontime run - Runs off PV ||
    || Midnight Classic 200 | 10, Evergreen 200w in a 160VOC array ||
    || VEC1093 12V Charger | Maha C401 aa/aaa Charger | SureSine | Sunsaver MPPT 15A

    solar: http://tinyurl.com/LMR-Solar
    gen: http://tinyurl.com/LMR-Lister ,

  • Lumisol
    Lumisol Registered Users Posts: 374 ✭✭✭
    High voltage arc from a battery, welding sparks, acids, etc.