Shattered PV panel mystery

Hi Guys,

I've got three shattered panels without any sign of foul play i.e. star marked impact points of "falling" rocks etc. No apparent stress or warping on the panel frames, all panels are mounted on the same two rails (top and base) yet the shattered panels are placed randomly thru out the array and to make matters even more puzzling, the affected panels are of different makes. One is a Spanish manufactured Isofoton panel, the other two are Kyocera.
The client says this shattering has occurred once before and I'm reluctant to fit more units until I know what's going on. Both incidents has been discovered during winter.
Location Southern Spain 600 Meters above sea level so hardly more than -5C in winter at the worst. Wind load is present but moderate due to location..........
I'm at loss here, any ideas?  

Jim Skau,  www.solarandalucia.net

  
8 x 250Wp Suntech (wife insisted on a dish washer), Outback VFX 3024, Midnite Classic 150, 4 Rolls 6CS25p. Solar installer in Southern Spain. 

Comments

  • AguarancherAguarancher Solar Expert Posts: 287 ✭✭✭
    edited December 2015 #2
    flimsy racking allowing the panels to twist, possibly in the wind? one other thought is if the rails aren’t parallel and the panels are clamped down to them, could cause twist in the panels, which over time could cause stress and crack the glass.
  • 706jim706jim Solar Expert Posts: 268 ✭✭✭
    Use them anyway as they should still work. I have a small panel with cracked glass. Only difference is that I know how it happened. (Didn't realize that it was glass and tried to drill holes in the corners!)
    Island cottage solar system with 2400 watts of panels, 1kw facing southeast 1kw facing southwest 400watt ancient Arco's facing south.Trace DR1524 MSW inverter, Trace C40 PWM controller 8 Trojan L16's. Insignia 11.5 cubic foot electric fridge. My 27th year.
  • Dave AngeliniDave Angelini Solar Expert Posts: 4,836 ✭✭✭✭✭
    What is the corrosion I see?  Are the panels mounted in the panel manufacturer hole locations? 
    "we go where power lines don't" Sierra Mountains near Mariposa/Yosemite CA
     http://members.sti.net/offgridsolar/
    E-mail [email protected]

  • BB.BB. Super Moderators, Administrators Posts: 29,697 admin
    Very hot day and spraying cold water on panels? No chance of hail?

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • jimskaujimskau Registered Users Posts: 21 ✭✭✭
    Hi Guys,

    Thank you for answering

    Just for your information. The array consists of 2 lines of 3 Kyocera 135Wp + 1 line of 3 Isofoton 110Wp ( VOC is 21V)
    The shattered panels work alright but with an obvious reduction. Problem here is that the client has a MPPT regulator so we are talking serious "solar salad" by now as the Amps differ a lot in the strings.
    I'd rather ditch the two 110Wp panels and collect the remnant 4 KD135 in one line and see if we can match this voltage within reason with a new set of replacements.

    Yes it's corrosion marks you see Dave. I reckon this panel (which I believe is a second hand replacement of a prior shattered panel) has been mounted in an untreated steel frame before, hence the rust marks on the aluminium frame.
    Hail? Well wouldn't the whole lot be smashed up if this was the case?
    Hot to cold in 1 second. Shattering has occurred during winter both times so temperature relatively stable.

    Although I didn't see any warping when eyeing the array from a flat angle, I tend to agree that the most likely cause is mechanical stress combined with wind load.
    I would still like to hear more comments though, as the consequence of my reckoning will cost the client a new structure before I hang any  panels.
    8 x 250Wp Suntech (wife insisted on a dish washer), Outback VFX 3024, Midnite Classic 150, 4 Rolls 6CS25p. Solar installer in Southern Spain. 
  • Dave AngeliniDave Angelini Solar Expert Posts: 4,836 ✭✭✭✭✭
    Are the panels mounted in the stock mounting holes or did some bozo drill hole in the panels to make them fit the rack?
    Instant warranty void!
    "we go where power lines don't" Sierra Mountains near Mariposa/Yosemite CA
     http://members.sti.net/offgridsolar/
    E-mail [email protected]

  • JohannJohann Solar Expert Posts: 240 ✭✭✭
    edited December 2015 #8
    Do you have pictures of the back side?

    What kind / material of the frame is the main structure made of?
  • sub3marathonmansub3marathonman Solar Expert Posts: 300 ✭✭✭
    jimskau said:

    Just for your information. The array consists of 2 lines of 3 Kyocera 135Wp + 1 line of 3 Isofoton 110Wp ( VOC is 21V)

    Although I didn't see any warping when eyeing the array from a flat angle, I tend to agree that the most likely cause is mechanical stress combined with wind load.
    I would still like to hear more comments though, as the consequence of my reckoning will cost the client a new structure before I hang any  panels.
    From the previous information, the nine panels are ground mounted in a single line of nine, if I've read things correctly.  Also, from one of the photos, two of the three shattered panels are side by side, which would seem to be where to start investigating.

    Is there a possibility of finding out where the previous panels were when they shattered?  Also, what position are the current panels that shattered?  Did any of the positions coincide for both incidents, or were they different?

    Since it is in the winter, I remember from when I lived where it was cold that the ground can really heave, as documented
    http://www.concretenetwork.com/concrete/frost_protected_shallow_footings/frost_actions_and_foundations.htm

    So is there a way to keep a check on the position of the posts relative to each other throughout the winter?  Maybe they're not installed deep enough for the actual temperatures encountered, as opposed to a general calculation which may have been used when the posts were installed?
  • jimskaujimskau Registered Users Posts: 21 ✭✭✭
    Very interesting point MarathonMan!  You might just have hit the spot.
    The array is mounted on a slope of normal dirt. It is very likely that the foundations are inadequate. I don't have any shots of the rear of the rig (sorry for that).
    I'll return to the site and take another thorough look + a mug shot of the rear of the rig.
    8 x 250Wp Suntech (wife insisted on a dish washer), Outback VFX 3024, Midnite Classic 150, 4 Rolls 6CS25p. Solar installer in Southern Spain. 
  • softdownsoftdown Solar Expert Posts: 2,686 ✭✭✭✭
    Seeing plenty of small rocks and dirt close to the panels. Possible that someone "burned out" with a car and threw a bunch of gravel and small rocks at the panels?

     Possible they got a little stuck and the tires were moving very fast as they tried to free themselves?
    First Bank:16 180 watt Grape Solar with  FM80 controller and 3648 Inverter....Fullriver 8D AGM solar batteries. Second Bank/MacGyver Special: 10 165(?) watt BP Solar with Renogy MPPT 40A controller/ and Xantrex C-35 PWM controller/ and Morningstar PWM controller...Cotek 24V PSW inverter....forklift and diesel locomotive batteries
  • DanS26DanS26 Solar Expert Posts: 240 ✭✭✭
    Sure looks like frost heave to me.   In freezing territory the footers need to be at an appropriate depth.  DIY install?
    18.2kW Kyocera panels; 2 Fronius 7.5kW inverters; Nyle hot water; Steffes ETS; Great Lakes RO; Generac 10kW w/ATS, TED Pro System monitoring with PVOutput.org
  • PhotowhitPhotowhit Solar Expert Posts: 5,022 ✭✭✭✭

    I'd vote for vandalism! Someone repeatedly throwing big rocks, or even shooting them! Is this a remote area with hunters?

    I've hand 1"+ hail, 60+ straight line winds, and even people who threw beer bottles at my array, and the only cracked panel I've had was when a strong wind blew over an 'A' frame temporary setup was blown over and only the very top panel was broken then. I've even seen some frame damaged panels, where the aluminum was hit hard enough to bow out above the glass and the glass didn't crack.

    They are pretty tough!

    Home system 4000 watt (Evergreen) array standing, with 2 Midnite Classic Lites,  Midnite E-panel, Prosine 1800 and Exeltech 1100, 660 ah 24v ForkLift battery. Off grid for @16 of last 17 years. Assorted other systems, and to many panels in the closet to not do more...lol
  • mike95490mike95490 Solar Expert Posts: 8,463 ✭✭✭✭✭
    I'd say impact of some sort.  First photo has a couple arc shaped shadows in the panel. impact at the center of the arcs.
    Photo of the pair,  impact point on the struts between the panels, pattern can be seen on the 2 panels going to the corner between them. IMHO.

    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

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  • sub3marathonmansub3marathonman Solar Expert Posts: 300 ✭✭✭
    edited December 2015 #15
    BB. said:
    Very hot day and spraying cold water on panels?

    -Bill
    Or maybe a very cold day and dumping hot water on the panels to melt ice/snow?  Then doing the Calvin of Calvin & Hobbs "Who Me?" after the disaster?  (Note: cartoon found with search at: http://michaelyingling.com/random/calvin_and_hobbes/ )

  • XizangXizang Registered Users Posts: 50 ✭✭
    Neighbor kids?  If not kids throwing rocks, could they be doing pullups on the panels, or using the array for playground equipment to climb on?
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