[RE-wrenches] Cooler Modules

[Mac Lewis]

Mark,
This question depends on what where you draw your system boundary.  If you
are analyzing a module in its entirety, the module that is converting
irradiance energy into electrical current will be cooler overall (less
thermal energy) because less of that irradiance energy is turning into
thermal energy.  However, if you look at individual cells, the module that
is conducting current can transfer some of that electrical energy into
thermal energy in bad cells, which will make localized heating.
Effectively, the modules producing useful work outside of your boundary
won't be be converting all of that radiation energy into thermal energy
inside of your boundary.

Hence, open circuit module warmer than conducting module.

This assumes that the only energy entering the system is from radiation,
and that energy can leave the system as electrical energy.

I like the question

On Wed, Sep 10, 2014 at 10:10 PM, William Miller <william at millersolar.com>
wrote:

> Colleagues:
>
>
>
> Thanks for the scintillating and relevant discussion.  This brings up a
> question on my radar:  Will unloaded modules fail sooner than loaded
> modules?
>
>
>
> Thanks again. Great Group!
>
>
>
> William
>
>
>
>
>
> [image: Gradient Cap_mini]
> Lic 773985
> millersolar.com <http://www.millersolar.com/>
> 805-438-5600
>
>
>
> *From:* RE-wrenches [mailto:re-wrenches-bounces at lists.re-wrenches.org] *On
> Behalf Of *Bill Hoffer
> *Sent:* Wednesday, September 10, 2014 9:04 PM
> *To:* RE-wrenches
> *Subject:* Re: [RE-wrenches] Cooler Modules
>
>
>
> Mark
>
>
>
> Loaded modules will have hotter cells. I know this from searching for bad
> cells with a thermal camera.  At open circuit I could not see a difference,
> but short circuit or loaded I could see 20 - 30 C increase in mismatched
> cells .
>
>
>
> Bill
>
>
>
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-- 



Mac Lewis

*"Yo solo sé que no sé nada." -Sócrates*
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