Shading effect on single MPPT inverter

Mbann
Mbann Registered Users Posts: 2 ✭
in Grid Tie and Grid Interactive Systems #1
Good day 
this is my first post here, 
I have a grid tied project where ill be using Jinko solar modules (JKM325PP-72) and ABB TRIO 50.0 TL3 single MPPT inverter.
I've got 10 strings of 16 series panel connected to the inverter, Due to site limitation one of these strings will be partially shaded through the morning hours (1-2 hours daily) 
My question is: Will this shaded string affect the output of other strings or the shading losses will only occur in the shaded string.

Thanks in advance 
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Comments

  • mcgivor
    mcgivor Solar Expert Posts: 3,854 ✭✭✭✭✭✭
    #2
    Welcome to the forum.
    The shaded panels within a string will affect the string as a whole, other strings not shaded will not be compromised, if the shading is during the early morning when angle of the sun is acute, there is generally little production to be lost, the hours between approximately 10 am. to 2 pm. is the critical period, where shading can have an impact on overall production. 
    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.
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  • Mbann
    Mbann Registered Users Posts: 2 ✭
    #3
    mcgivor said:
    Welcome to the forum.
    The shaded panels within a string will affect the string as a whole, other strings not shaded will not be compromised, if the shading is during the early morning when angle of the sun is acute, there is generally little production to be lost, the hours between approximately 10 am. to 2 pm. is the critical period, where shading can have an impact on overall production. 
    Thank you for your response , 
    I've been told that since the current of the shaded string will be lowered the MPPT algorithm will try to find the maxiumum power point for all the strings , since the voltage is constant on the parallel strings the current on all strings will be lowered to match the shaded string current. 
    is that correct or not 
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  • mcgivor
    mcgivor Solar Expert Posts: 3,854 ✭✭✭✭✭✭
    #4
    The shaded string will in effect be disconnected, the ballance of strings, 9 in your case, would provide all the power at that point, the "bad" string would not pull down the  "good" strings" it would simply not contribute to the overall production, until it receives sun, then it will contribute it's share of the input, the MPPT will sweep the input to find when this occurs.
    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.
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  • boB
    boB Solar Expert Posts: 1,032 ✭✭✭✭
    #5
    Partial shading can be mitigated much of the time by using a chain-saw

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