Panel Shade Affect on Entire String

lzhomelzhome Posts: 38Registered Users ✭✭
edited October 2017 in Solar Product Reviews & Opinions #1
Today at 4pm on October 18th I have about 3 inches of shade across the bottom of two panels horizontally mounted. These two serial connected 12v 100w panels are parallel connect to 2 more panels for a 24v string of 4 panels. This shade will only be present during the winter months.

 Will this shade have negative effects on the other two panels in the string? I will be installing two more strings in the exact same manner, with same shade.

Oops, put this in the wrong category. can't more so hope a Moderator does it for me.
TriStar MPPT, 8 x 100w PV, MNPV6 Combiner, 4 x 12v 155ah VMAXTanks AGMs and GoPower 2000w PSW Inverter.
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Comments

  • PhotowhitPhotowhit Posts: 4,706Solar Expert ✭✭✭✭
    edited October 2017 #2
    Yes, It would be more effective if you can connect the 2 shaded panels in series and 2 sunny panels in series.

    FWIW - I connected mine this way with side by side panels connected and found my early and late day shading comes from the sides, so I should really connect mine up and down...lol.

    Home system 4000 watt (Evergreen) array standing, with 2 Midnite Classic Lites,  Midnite E-panel, Prosine 1800 and Exeltech 1100, ForkLift battery. Off grid for @13 of last 14 years. 1000 watts being added to current CC, @2700 watts to be added with an additional CC.
  • Raj174Raj174 Posts: 643Solar Expert ✭✭✭✭
    #3
    lzhome,
    The power output will be reduced about one third in a string shaded in this way. If it were shaded across the short side, output on the entire string would be near 0.

    Rick
    3600W PV, MNE175DR-TR epanel modified, MN Classic 150, Outback Radian GS4048A, Mate3, 54.4V 207AH LiFePO4 no BMS, 4500W genset.
  • mcgivormcgivor Posts: 2,212Solar Expert ✭✭✭✭✭
    #4
    lzhome said:
    Today at 4pm on October 18th I have about 3 inches of shade across the bottom of two panels horizontally mounted. These two serial connected 12v 100w panels are parallel connect to 2 more panels for a 24v string of 4 panels. This shade will only be present during the winter months.

     Will this shade have negative effects on the other two panels in the string? I will be installing two more strings in the exact same manner, with same shade.

    Oops, put this in the wrong category. can't more so hope a Moderator does it for me.
    Is the shade a morning or evening event or during peak hours? 
    1500W, 6× Schutten 250W Poly panels , Schneider MPPT 60 150 CC, Schneider SW 2524 inverter, 400Ah LFP 24V nominal battery bank 

  • lzhomelzhome Posts: 38Registered Users ✭✭
    #5
    Morning and peak hours are fine, this is late afternoon as I mentioned 4pm.
    TriStar MPPT, 8 x 100w PV, MNPV6 Combiner, 4 x 12v 155ah VMAXTanks AGMs and GoPower 2000w PSW Inverter.
  • mcgivormcgivor Posts: 2,212Solar Expert ✭✭✭✭✭
    #6
    Personally I wouldn't worry about it, the critical time is the peak period, production would be so low at 4pm, it would be negligible. Sorry missed the 4pm in your OP.
    1500W, 6× Schutten 250W Poly panels , Schneider MPPT 60 150 CC, Schneider SW 2524 inverter, 400Ah LFP 24V nominal battery bank 

  • EstragonEstragon Posts: 2,840Registered Users ✭✭✭✭✭
    #7
    The shadow will move higher and last longer over the next couple of months though. Around here 2pm in a couple of months will look a lot like 4pm now.
    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
  • lzhomelzhome Posts: 38Registered Users ✭✭
    #8
    Estragon said:
    The shadow will move higher and last longer over the next couple of months though. Around here 2pm in a couple of months will look a lot like 4pm now.
    @Estragon Good point.
    Kinda related but different question. I've only installed two panels as a proof of concept on mounting panels on top of my metal building. I check the panels several times a day for shade and alignment and here in the South the panels are covered with dew in the morning which takes a while to vaporize. Does anyone use Rainx or other types of glass polish to disperse water more effectively?
    TriStar MPPT, 8 x 100w PV, MNPV6 Combiner, 4 x 12v 155ah VMAXTanks AGMs and GoPower 2000w PSW Inverter.
  • EstragonEstragon Posts: 2,840Registered Users ✭✭✭✭✭
    #9
    I wouldn't worry about dew. If there isn't enough sun to vaporize it, the panels wouldn't be producing much anyway.
    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
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