Jesse,
Look at the "NOCT" temperature specification for the PV module(s) of interest
to you. The lower the number, the better a module dissipates [unwanted] heat.
As previously mentioned, this value is measured and recorded by the NRTL during
UL1703 certification.
Dan
--------------------------------------------
On Fri, 3/14/14, Solar <dahlso...@gmail.com> wrote:
Subject: Re: [RE-wrenches] Uni-Solar, Kaneka.now Panasonic?
To: "RE-wrenches" <re-wrenches@lists.re-wrenches.org>
Date: Friday, March 14, 2014, 12:44 PM
Can anyone point to data that compares module construction and it's ability to
dissipate heat?
I've installed many silicon energy (glass on glass) modules and when doing so
in the summer it's been hard to touch them due to the glass being so hot. The
other manufacturer here in MN (TenK) uses an aluminum back and they claim this
dissipates heat better them typical module construction.
For a test last summer I installed a few silicon energy modules with Tigos. I
never saw their 190W module produce over 154W (tilt of 35 degrees, straight
south) not exactly scientific, but thought the glass on glass construction
might be at work.
Jesse
Sent from my iPhone
> On Mar 14, 2014, at 12:24 PM, Exeltech <exelt...@yahoo.com> wrote:
>
> Larry,
>
> As August pointed out, there are too many variables related to PV performance
> to focus on just one and call it "good". He's right on target.
>
> For a very simplistic example...
>
> One aspect of PV performance relates to cell temperature, which in turn is
> affected by the NOCT rating of the PV. NOCT ("nominal operating cell
> temperature" is an indicator of a PV module's ability to dissipate unwanted
> heat. Higher values of NOCT indicate a module that will have hotter cells
> than PV with a lower value for NOCT (all other things being equal).
>
> Let's say you're comparing two PV that have similar temperature coefficients,
> but different values for the NOCT.
>
> PV 'A' has a slightly worse temperature coefficient, but a lower NOCT than PV
> 'B'.
>
> On paper, looking only at the temperature coefficient, it would appear PV 'B"
> would outperform PV 'A'.
>
> However, in this example, PV 'A' would be operating at a lower cell
> temperature due to its superior ability to dissipate heat. The ultimate cell
> temperatures of PV 'A' may be sufficiently cooler than PV 'B" to allow it to
> equal or even slightly outperform PV 'B".
>
> Incidentally, NOCT is measured and reported by the NRTL during certification.
> The manufacturer simply prints this value in their PV specs.
>
>
> As with anything .. your mileage....
>
>
> Dan
>
> --------------------------------------------
> On Fri, 3/14/14, Larry Crutcher, Starlight Solar Power Systems
> <la...@starlightsolar.com> wrote:
>
> Subject: [RE-wrenches] Uni-Solar, Kaneka…now Panasonic?
> To: "RE-wrenches" <re-wrenches@lists.re-wrenches.org>
> Date: Friday, March 14, 2014, 10:33 AM
>
> Wrenches,
>
> What high performance PV modules are being sold in the US? I can't find
> Panasonic modules anymore. I have written to them twice but they can't direct
> me to any distribution in the US. They insist that Sunwize will have them but
> Sunwize says they have no plans yet to purchase again.
>
> From what I can tell, the next best thing is Sunpower modules with -0.38% /K
> temp coefficient. Are there any others to consider?
>
> Larry Crutcher
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