Thin film or poly?

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stephendv
stephendv Solar Expert Posts: 1,571 ✭✭
I'm finally entering the planning stage for a 3kW off-grid PV system in Spain and have some quotes for panels that have me reconsidering the thin film option. System will be 48V.

First offer: 1.53 Euro/Watt for poly Yingli panels. Guaranteed 80% for 25 years.
Second offer: 1.1 Euro/Watt for Nexpower thin film modules. Guaranteed 80% for 20 years. Vmp = 73V, Voc = 100V, so they'd work quite nicely on an MPPT with a 48V battery.

Mounting will be on a 60 sqm roof facing due south which will easily fit the thin films. The only extra costs will be mounting rails and cabling. So the big question: does the price difference warrant the risk of choosing thin film?

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  • Solar Guppy
    Solar Guppy Solar Expert Posts: 1,989 ✭✭✭
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    Re: Thin film or poly?

    Stay away from thin film, they have no long term data to prove they will last the time they have printed on a piece of paper. Most Thin film company are not doing well financially and I would go as far to say in 5+ years most the current film manufactures will be gone.

    What ever you buy, a warranty is only as good as the company behind it ... 25 years? I can count on one hand how many PV company's have been around that long to support the products.
  • Dave Angelini
    Dave Angelini Solar Expert Posts: 6,776 ✭✭✭✭✭✭
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    Re: Thin film or poly?

    Ditto! The shipping on thin film because of the huge size increase and weight.
    This is progress?
    "we go where power lines don't" Sierra Nevada mountain area
       htps://offgridsolar1.com/
    E-mail offgridsolar@sti.net

  • stephendv
    stephendv Solar Expert Posts: 1,571 ✭✭
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    Re: Thin film or poly?
    What ever you buy, a warranty is only as good as the company behind it

    ...and as good as the Insurance company that underwrites it ;) I don't expect to ever have to return panels under 80% - 25 year guarantee because the terms of those are just ridiculous for a small time installation. It usually involves taking the defective panel to a lab who can test it under STC, then ship it to the company's headquarters, etc etc.

    The nexpower panel guarantees are underwritten by MunichRE in Germany, so while I may never claim on the guarantee, the fact that the insurer has done it's research and is willing to underwrite them is some form of comfort as to their quality.

    I hear you on the non-proven track record though... thing is at a certain price point, the risk starts looking rather attractive.

    PS. these panels are distributed by Shueco in the US who I believe is a big name in the solar biz.
  • niel
    niel Solar Expert Posts: 10,300 ✭✭✭✭
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    Re: Thin film or poly?

    it won't be just a bit more for mounting as thin film requires almost double the area of the more efficient crystalline types. add to that an extra 20% of time in the warranty and to me that's a no brainer. are you worried that something may break the glass of a pv as that's about the only good thing about thin film and the reason i went with my thin films. those that already attempted to break them have already figured it out that they did not succeed meaning that i can upgrade to crystalline without too much worry.
  • Dave Angelini
    Dave Angelini Solar Expert Posts: 6,776 ✭✭✭✭✭✭
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    Re: Thin film or poly?

    For me the warranty is based on my distributor out here in California. I just bring them the bad panel and I get cash or another panel. All they want is a serial number and a picture of the label on the back of the panel. This the main reason to do business with a good distributor in driving range for glass solar panels in my opinion!

    Another reason to stay away from these panels is the weight lifting them on to their mounts. For offgrid you have to be a little crazy to scrimp on the main source of energy.
    "we go where power lines don't" Sierra Nevada mountain area
       htps://offgridsolar1.com/
    E-mail offgridsolar@sti.net