Thin-film modules

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Soulbringer
Soulbringer Registered Users Posts: 17 ✭
in Advanced Solar Electric Technical Forum #1
Hello solar boys and girls :-),

My idea is to buy a thin-film modules to test them especially in summer months. I`m from Bulgaria (west-south part-Petrich) where the temperatures increase up to 40 degrees (in July and August) and thin-film modules have better temp. coefficient so I need to compare them with mono and poly.
So can you recommend me a good configuration (modules+inverters) up to 1KWp. Thanks
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  • Solar Guppy
    Solar Guppy Solar Expert Posts: 1,989 ✭✭✭
    #2
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    Re: Thin-film modules

    Thin films aren't any better with tempature ... at least the ones that publish specs. I've compared a couple and its in the noise the difference between mono/poly Si to Asi
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  • BB.
    BB. Super Moderators, Administrators Posts: 33,439 admin
    #3
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    Re: Thin-film modules

    In fact, the UniSolar thin film panels (as an example) are about 10% worse temperature coefficient compared to a generic SI panel (lose more voltage hot, gain more voltage when cold)...

    The higher working voltages of many mono/poly-crystalline panels vs the currently available thin film panels appears to make the TC look worst--divide the panel's TC by the working voltages and then compare (normalizing the panels' TC to the same scale).

    Also, historically, Asi type panels have degraded outputs over time when exposed to sun and weather--hopefully the new ones will be better, but it will take years and many panels before we know for sure (and each vendor gets a track record). Don't spend money that you can't afford to lose if something goes wrong in your testing.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
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  • niel
    niel Solar Expert Posts: 10,300 ✭✭✭✭
    #4
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    Re: Thin-film modules

    i agree that you shouldn't just hear a rumor and go with that as you will also find some worse than unisolar. unless you need a more durable surface (break resistant) then the mono and poly si pvs are better to buy in a general sense, but as i said do compare. thin films are also less efficient meaning you'll need more of an area to collect the same power as those of the mono and poly si pvs.
    as to what bill said here, "Also, historically, Asi type panels have degraded outputs over time when exposed to sun and weather" you will find all pvs degrade over time, but what i think he meant to say was that asi types will do this a bit moreso.
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  • BB.
    BB. Super Moderators, Administrators Posts: 33,439 admin
    #5
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    Re: Thin-film modules

    Actually, from here (SG site), Asi historically has been a huge problem (as in early life failures)... UniSolar may do better (I have no information one way or the other)--but without some independent history, I would not pay Si type pricing for them (perhaps, they (Thin Film, Asi) are worth $1.00 watt).

    And, flexible panels have difficulties getting good weather tight seals (flexing at joints and seams is a failure point for virtually any manufactured product where water and air can enter)... And the new Thin Film panels are supposed to require hermetically sealed arrays since the materials are so sensitive to degradation by Oxygen.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
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  • n3qik
    n3qik Solar Expert Posts: 741 ✭✭
    #6
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    Re: Thin-film modules

    I have 7 of the Uni-solar ES-62T panels. They are rated Isc 5.1 amps. Just did a test this weekend, they are at 4.4 to 4.2 amps. I was getting around 5 amps when they where new 6 months ago.

    I hope they get better in the summer, but I think not.


    I think thin-film will get better, but this may be in 5-10 years.
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  • BB.
    BB. Super Moderators, Administrators Posts: 33,439 admin
    #7
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    Re: Thin-film modules

    Amorphous panels (the non-crystalline types you typically find on cheap yard lights and other low end "solar devices" will lose 20% of their output capacity in sunlight (and, IIRC, it will continue to drop 20% every additional 6 months).

    Don't know about the UniSolar... Tried a quick google and got one interesting report from ~1996-99--but they just gave the results for Vendor A, B, C, etc... Some were just fine, others had 50% failures (~11 watt panels used in Kenya).

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
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  • n3qik
    n3qik Solar Expert Posts: 741 ✭✭
    #8
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    Re: Thin-film modules

    Those are the 15W panels Harbor Freight and others sell. They are made by SHENZHEN TOPRAY SOLAR CO.,LTD. SHENZHEN has sued the original poster of that report to remove their name/report.

    Here is the a copy the names company names:
    http://www.humboldt.edu/~aej1/AJTips_No9_Solarnet_Sept_2005.pdf
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  • BB.
    BB. Super Moderators, Administrators Posts: 33,439 admin
    #9
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    Re: Thin-film modules

    Thank you N2qik!

    Looking around the Professor's website, I found a 2002 report (PDF) that has lots of good information on life and failure rates...

    Interestingly, amorphous panels have an initial drop in the first 6 months or so of use--then experience roughly the same amount of light degradation as crystalline solar panels out 10-20 years (10 years typical warranty life for amorphous and 20 year for crystalline panels).

    Sounds like the companies know how to make good panels--the issue is whether or not they want to take the effort to do so...

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
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  • newenergy
    newenergy Solar Expert Posts: 291 ✭✭✭✭✭✭
    #10
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    Re: Thin-film modules
    n3qik wrote: »
    I have 7 of the Uni-solar ES-62T panels. They are rated Isc 5.1 amps. Just did a test this weekend, they are at 4.4 to 4.2 amps. I was getting around 5 amps when they where new 6 months ago.

    I hope they get better in the summer, but I think not.


    I think thin-film will get better, but this may be in 5-10 years.

    You really need to measure the amount of light hitting the panels to compare the current. The temperature has a little effect, but it mostly affects voltage. Hopefully they haven't deteriorated that much.
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  • n3qik
    n3qik Solar Expert Posts: 741 ✭✭
    #11
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    Re: Thin-film modules
    newenergy wrote: »
    You really need to measure the amount of light hitting the panels to compare the current. The temperature has a little effect, but it mostly affects voltage. Hopefully they haven't deteriorated that much.

    My panels are tilted for the summer sun. That is why I hope they do better this summer. They where facing the sun but should have been tilted up another 15 deg. when I did the test.
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  • n3qik
    n3qik Solar Expert Posts: 741 ✭✭
    #12
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    Re: Thin-film modules

    Update: 12 days later.

    Just did another Isc test, all panels are at 4.6 Amps. :D:D
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