SunPower Solar Cell Discoloration

newmex999
newmex999 Registered Users Posts: 7 ✭
in Advanced Solar Electric Technical Forum #1
Hello

I had a SunPower system(E20 327 panels) installed about 6 months ago and just recently noticed that some of the cells are discoloring. It appears to be a few cells in several of the panels.

The only information I was able to find was here: http://guntherportfolio.com/2013/03/new-sunpower-solar-cell-discoloration-anomalies-at-the-photovoltaic-demonstration-project/
And it appears this gentleman was trying to find out from SunPower if this was just aesthetics or a reliability and power output issue and has not received an answer back yet.

Let me know if anyone on this forum has any knowledge of this issue and can provide me with more information?

Thanks
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Comments

  • zoneblue
    zoneblue Solar Expert Posts: 1,220 ✭✭✭✭
    #2
    Re: SunPower Solar Cell Discoloration

    Maybe put a photo up.
    1.8kWp CSUN, 10kWh AGM, Midnite Classic 150, Outback VFX3024E,
    http://zoneblue.org/cms/page.php?view=off-grid-solar


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  • newmex999
    newmex999 Registered Users Posts: 7 ✭
    #3
    Re: SunPower Solar Cell Discoloration
    zoneblue wrote: »
    Maybe put a photo up.

    Went up on roof when I got home yesterday to snap some photos and lo and behold the lighter cells were not very visible? This was around 4:30pm and sun was not overhead.
    I will check again on the weekend and see if they are more noticeable when the sun is directly overhead and take some pictures.
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  • newmex999
    newmex999 Registered Users Posts: 7 ✭
    #4
    Re: SunPower Solar Cell Discoloration
    newmex999 wrote: »
    Went up on roof when I got home yesterday to snap some photos and lo and behold the lighter cells were not very visible? This was around 4:30pm and sun was not overhead.
    I will check again on the weekend and see if they are more noticeable when the sun is directly overhead and take some pictures.

    Here are some pictures. These lighter color cells seem to show up when the sun is directly overhead and only if you look at the panel from back to front(in other words, from the high end of the panel towards the low end). If I go around to the front of the panel and look at it, the cells in question are a little lighter then the surrounding cells, but not as pronounced.
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  • newmex999
    newmex999 Registered Users Posts: 7 ✭
    #5
    Re: SunPower Solar Cell Discoloration

    Hello-any insight after seeing the pictures?
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  • BB.
    BB. Super Moderators, Administrators Posts: 33,631 admin
    #6
    Re: SunPower Solar Cell Discoloration

    I don't like variations in panels--But I don't have a lot of experience to say what is happening to the panels in your pictures.

    But, quality is becoming a big issue over the last few years:

    http://www.nytimes.com/2013/05/29/business/energy-environment/solar-powers-dark-side.html?pagewanted=all&_r=1&
    No one is sure how pervasive the problem is. There are no industry wide figures about defective solar panels. And when defects are discovered, confidentiality agreements often keep the manufacturer’s identity secret, making accountability in the industry all the more difficult.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
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  • zoneblue
    zoneblue Solar Expert Posts: 1,220 ✭✭✭✭
    #7
    Re: SunPower Solar Cell Discoloration

    Ive never seen anything like that. What does the cell look like close up?
    1.8kWp CSUN, 10kWh AGM, Midnite Classic 150, Outback VFX3024E,
    http://zoneblue.org/cms/page.php?view=off-grid-solar


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  • Cariboocoot
    Cariboocoot Banned Posts: 17,615 ✭✭✭
    #8
    Re: SunPower Solar Cell Discoloration

    Ultimately this is a warranty issue and the only opinion that matters is what the maker says. They may say it's a problem and replace them or they may say it's fine, don't worry about it. Of course in the latter case they may be lying to get out of the liability. So report it now and then check the output regularly to be sure there really is no functional difference. That way you'll at least be able to say "I told you so".
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  • SolarPowered
    SolarPowered Solar Expert Posts: 626 ✭✭✭
    #9
    Re: SunPower Solar Cell Discoloration

    1 in 7 panels will look like this either new, or over time, its what grade A cells do, its normal. The more blue in content the better the ingot cell is as far as conversion. The 17% and 18% panel cells are typically much darker black in color.
    All that really matters is accounting for the VOC/ISC, looks of the cells means nothing.
    The 327 has a depreciation rate of .04% over the course of each year, the same as the 435 and the 430 as they are maxeon cells.
    Can you tell me what your VOC and ISC is at 25* tilt due south 180* azimuth? If your ameter cannot generate in a measurement of thousands amps I can calculate in mili amps to get you your answer and what is your latitude/longitude and I can tell you if it is the correct depriciation. If Installed within 6 months and through the dead of winter your depriciation should only be .028% at most.

    WARNING: If you aren't the installer you shouldn't be disconnecting the panel it voids warranty under your contract conditions. Contact your certified contractor before proceeding forward

    Kindest Regards
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  • tempestv8
    tempestv8 Registered Users Posts: 1 ✭
    #10
    Joining this conversation a little late in 2017 but still relevant, I think.

    I have received a batch of brand new SunPower E20 - 327 watt panels from a local SunPower Australia recommended PV installer.

    Looking at the panels, I can see that the cells are not even in colour.  Some of the discoloration look quite severe, but here is a picture of a whole panel.  As can be seen the panel is "patchy" looking.

    Based on this thread discussion, I am guessing it is normal, but just thought I'd chime in to the conversation


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  • littleharbor2
    littleharbor2 Solar Expert Posts: 2,113 ✭✭✭✭✭
    edited April 2017 #11
    Hopefully they won't begin to look like these after a few years. Please excuse the incomplete photo. My internet in Baja is painfully slow right now.

    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.

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  • mcgivor
    mcgivor Solar Expert Posts: 3,854 ✭✭✭✭✭✭
    #12
    @littleharbor2 Those are some seriously Baja baked panels, do they still produce?  Or is that the before replacement photo?
    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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  • Dave Angelini
    Dave Angelini Solar Expert Posts: 6,908 ✭✭✭✭✭✭
    #13
    You do not have to go to baja for defective Sun Power panels.  I have heard they regret ever letting these get into the secondary market. Plenty of these at a customers house here in Mariposa near latitude 38.
    They should have been destroyed. :'(
    "we go where power lines don't" Sierra Nevada mountain area
       htps://offgridsolar1.com/
    E-mail offgridsolar@sti.net

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  • littleharbor2
    littleharbor2 Solar Expert Posts: 2,113 ✭✭✭✭✭
    #14
    Just a stock photo. Not my personal panels. I have a couple sunpower panels with browned out cells but not quite this bad. Oh and they do work ok.

     Everything here in Baja, solar wise, is working perfectly right now despite having 4 women in the house with all their blow dryers and hair irons. I'm just looking at it as "exercise" for the system.  And I don't have a sunpower system here. My sig. shows what I have here.

    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.

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  • softdown
    softdown Solar Expert Posts: 3,925 ✭✭✭✭
    #15
    Seems to me that a few cells varying in color over the years is almost the norm.
    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
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