100 watt solar panels

DcmikeDcmike Registered Users Posts: 19 ✭✭
i have six 100 watt solar panels, 2 from renogy 2 from Missouri wind and solar and 2 from windy nation. i have a 24 volt system so i hook each set into pairs. my problem is the windy nation panels seem to be ok when i measure voc and the isc when not hooked up to any thing. but when i hooked them up to my system my tracer software only reads their out put around 1.19 amps but the renogy and Missouri ones all read over 5 amps. anyone have and idea as why they dont work while hooked up?
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Comments

  • littleharbor2littleharbor2 Solar Expert Posts: 707 ✭✭✭✭
    Sounds like one of the panels has a problem. Can you hook each one of them up in series with one of the other panels? This should allow you to weed out the bad panel. If you can determine which is the bad panel you ought to try to get it replaced under warranty.

    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, 700 ah @24 volt AGM battery bank. Plenty of Baja Sea of Cortez sunshine.

  • DcmikeDcmike Registered Users Posts: 19 ✭✭
    it just the windy nation ones i tested the voc and isc and when not hooked up they seem ok but just soon as i hook them up they dont produce much power. got me a little confused cus the other pairs work just fine 
  • littleharbor2littleharbor2 Solar Expert Posts: 707 ✭✭✭✭
    Isc. and Voc. is not under any kind of load. Can you get a automotive brake light bulb or some other 12 volt load and test each panel individually?

    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, 700 ah @24 volt AGM battery bank. Plenty of Baja Sea of Cortez sunshine.

  • EstragonEstragon Registered Users Posts: 1,633 ✭✭✭✭
    Maybe the windy nation panels are a bit lower vmp than the others?
    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
  • DcmikeDcmike Registered Users Posts: 19 ✭✭
    edited July 13 #6
    both renogy and windy nation  panels vmp are like 17.6 range not sure on the missouri ones but the put out the amps i think they should. just so most understand if i mix one of the windy nation panels with another panel it kills the amp out put too when hooked up to charge controller . and on another note i looked at the diode and measured them they looked and measured the same 
  • BB.BB. Super Moderators Posts: 26,874 admin
    You need loads to draw maximum current from the array.

    Either the battery bank needs to be under ~85% state of charge, or your load needs to be greater than Imp of the array. Or a combination of the two.

    If the charge controller does not think the batteries need the full current (not in bulk stage but in absorb stage).

    Basically, the charger needs to be in bulk mode and see around 13.6 volts or less at the battery so that it allows full current from the array.

    - Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • DcmikeDcmike Registered Users Posts: 19 ✭✭
    edited July 15 #8
    bb i understood that . that why i tested the 3 sets of panels with in a minutes of each other so there wouldn't be that big of a difference in readings, when i tested the renogy/missouri panels they all were 5,5 amps or better and the windy nation ones read only 1.09 amps
  • EstragonEstragon Registered Users Posts: 1,633 ✭✭✭✭
    So you unhooked 2 of the 3 pairs in sequence to do the test, with a single pair connected to the controller?

    If so, my guess is a faulty connection somewhere.
    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
  • mcgivormcgivor Registered Users Posts: 1,305 ✭✭✭✭
    Sounds like bad diodes bypassing strings of cells within the panel,  if everything else looks good, try removing the diodes for a temporary test, HINT, take a picture to record the orientation, without the diodes in place, full output would be revealed, at least then you would know if in fact the cells are good, diodes are cheap to replace.
      1500W, 6× Schutten 250W Poly panels , Schneider 150 60 CC, Schneider SW 2524 inverter, 8×T105 GC 24V nominal 

  • mike_smike_s Registered Users Posts: 39 ✭✭
    edited July 14 #11
    Dcmike said:
    bb i understood that . that why i tested the 3 sets of panels with in a minute of each other
    If you get reasonable Isc, I don't see how it can be a connection or blocking diode problem unless it's intermittent - since that proves the connections can carry full current. Same with Voc and bypass diodes - a shorted diode would reduce Voc, and an open one would have no effect unless the panel were shaded.

    You said "Tracer." MPPT, right? I don't know the gory details on the algorithm it uses, but you may have to leave each set hooked up longer than "within a minute" to let it do a full sweep. Perhaps it did a sweep while the panels were disconnected, came up with a not-so-good solution, and kept that when the Windy Nation panels were connected? 
  • DcmikeDcmike Registered Users Posts: 19 ✭✭
    edited July 14 #12
    just today i did another test of the panels and i used a victron blue mppt charge controller (it has a pretty instant scan mode) and got same results as yesterday basically. when i hooked up the 2 windy nation panels i got 30 some volts and 1.9 amp but only 28 watts. hooked the 4 year old Missouri wind panels and bang i got 175 watts 30 some volts and 8.5 amps . im gonna look at the cells on the panels today and see if any thing is burnt and that why they dont work right . one good note windy nation is sending me one panel they for think is bad 
  • mike_smike_s Registered Users Posts: 39 ✭✭
    Dcmike said:
    when i hooked up the 2 windy nation panels i got 30 some volts and 1.9 amp but only 28 watts.
    ?
    30 V x 1.9 A = 57 W, not 28 W.
    30 V x 8.5 A = 255 W, not 175 W.

    Where are those numbers coming from?
  • DcmikeDcmike Registered Users Posts: 19 ✭✭
    edited July 14 #14
    the victron blue software 
  • mcgivormcgivor Registered Users Posts: 1,305 ✭✭✭✭
    edited July 15 #15
    mike_s said:
    If you get reasonable Isc, I don't see how it can be a connection or blocking diode problem unless it's intermittent - since that proves the connections can carry full current. Same with Voc and bypass diodes - a shorted diode would reduce Voc, and an open one would have no effect unless the panel were shaded.




    Diodes generally fail short circuit but don't necessarily fail completely, there can be deterioration over time resulting in partially shorted diode, this would appear as reduced current, but not necessarily lower VOC. Temporarily removing the diodes would eliminate the possibility of a partial bypass, revealing the actual current the panel can supply, if it is still low, then possible cell damage has occurred. Always replace the diodes after testing.
      1500W, 6× Schutten 250W Poly panels , Schneider 150 60 CC, Schneider SW 2524 inverter, 8×T105 GC 24V nominal 

  • mike_smike_s Registered Users Posts: 39 ✭✭
    mcgivor said:
    Diodes generally fail short circuit but don't necessarily fail completely, there can be deterioration over time resulting in partially shorted diode, this would appear as reduced current, but not necessarily lower VOC. 
    Explain how he then gets full Isc.
  • mike_smike_s Registered Users Posts: 39 ✭✭
    Dcmike said:
    the victron blue software 
    24V system, with the battery at 16.07V, and a charge state of float? Something's wrong, and it's not the panels.

  • mcgivormcgivor Registered Users Posts: 1,305 ✭✭✭✭
    mike_s said:
    mcgivor said:

    Diodes generally fail short circuit but don't necessarily fail completely, there can be deterioration over time resulting in partially shorted diode, this would appear as reduced current, but not necessarily lower VOC. 
    Explain how he then gets full Isc.

    Working with second hand information in a ping pong communication is difficult, especially when it seems that things don't look right, my suggestions are a means, through process of elimination, to determine what the problem is, an offer of help, which can be accepted or ignored, it's just what I would do in similar circumstances. Not being there, I can neither  confirm nor deny what the instruments used, recorded, I can however say, electronic components can mislead one into believing the instruments used are correct, when in fact they are not  40 plus years of experience has shown me that things are not always what they seem. Personally I would want to know why something doesn't work, knowledge is earned and information is not knowledge. There is no intention to insult your comment, in fact all coments are valuable, if they are positive.
      1500W, 6× Schutten 250W Poly panels , Schneider 150 60 CC, Schneider SW 2524 inverter, 8×T105 GC 24V nominal 

  • DcmikeDcmike Registered Users Posts: 19 ✭✭
    edited July 15 #19
    mike_s said:
    Dcmike said:
    the victron blue software 
    24V system, with the battery at 16.07V, and a charge state of float? Something's wrong, and it's not the panels.

    i had put the panels on the victron blue mppt it a different system than the 24 volt system on the tracer mppt from my 1st post sorry about confusion 
  • littleharbor2littleharbor2 Solar Expert Posts: 707 ✭✭✭✭
    Have you isolated the bad panel yet?

    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, 700 ah @24 volt AGM battery bank. Plenty of Baja Sea of Cortez sunshine.

  • DcmikeDcmike Registered Users Posts: 19 ✭✭
    Have you isolated the bad panel yet?
    yes i have taken them off the system now and working with windy nation to get it right. they are sending one new panel for the one they are for sure think is bad but i pretty sure both are bad. i dont wanna mess with diodes just yet if they want panels back for warranty 
  • mike_smike_s Registered Users Posts: 39 ✭✭
    Are you going to provide details, or just let us keep guessing?

    Making the assumption that it's a 12 V system, using lead acid batteries, one wonders why it's floating at 16 V. Anyway, since it's floating not charging, it only takes minimal current to hold the voltage so it's not a valid indication of what the panels are capable of. As has been mentioned multiple times, you need to put a load on it if you want to see what the panels can do.
  • DcmikeDcmike Registered Users Posts: 19 ✭✭
    well the details on the my 1st post on the 24 volt system is 2 agm 155ah battery's now the victon blue mppt is on a lithium battery pack that i did not wanna say about because it erks to many when you mention lithium battery's . 
  • littleharbor2littleharbor2 Solar Expert Posts: 707 ✭✭✭✭
    Did you try to put a load on both of those panels? That would easily weed out any problems.

    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, 700 ah @24 volt AGM battery bank. Plenty of Baja Sea of Cortez sunshine.

  • DcmikeDcmike Registered Users Posts: 19 ✭✭
    Did you try to put a load on both of those panels? That would easily weed out any problems.
    thats how figured they were bad, when just checking they seem fine, but soon as i hook them up to any charge controller i have they just wont put out the amps they should
  • littleharbor2littleharbor2 Solar Expert Posts: 707 ✭✭✭✭
    So you hooked up one at a time?

    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, 700 ah @24 volt AGM battery bank. Plenty of Baja Sea of Cortez sunshine.

  • DcmikeDcmike Registered Users Posts: 19 ✭✭
    So you hooked up one at a time?
    yes i even have a 12 volt system not mentioned and have tried them one at a time on that system with out any good results 
  • littleharbor2littleharbor2 Solar Expert Posts: 707 ✭✭✭✭
    OK, good to know.  I now wonder if Windy nation has a problem run of panels. Two bad panels is unlikely unless a problem batch or there was some catastrophic event took them out.

    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, 700 ah @24 volt AGM battery bank. Plenty of Baja Sea of Cortez sunshine.

  • DcmikeDcmike Registered Users Posts: 19 ✭✭
    well with 100 watts panels getting so cheap and most made in china, i wouldn't doubt they have a bad run of them every now and then
  • littleharbor2littleharbor2 Solar Expert Posts: 707 ✭✭✭✭
    12 volt panels are still relatively expensive. I have 285 watt 24 volt panels for $100.00 and can hardly sell them now that the price of larger panels have dropped so low.

    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, 700 ah @24 volt AGM battery bank. Plenty of Baja Sea of Cortez sunshine.

  • DcmikeDcmike Registered Users Posts: 19 ✭✭
    i so wanted to get 24 volt panels but the dang truck shipping is to much. so i just stick with 100 watt panels
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