[RE-wrenches] module hot spots

[William Dorsett]

I suspect that SunPower gets their advertised high performance, not from
having better technology, but by being more selective in matching higher
power cells than just randomly divvying up cells off a common factory run.
The module you've found Marco may just be a slipup in sorting (nothing is
100%) and may not indicate a change in that module but just what that module
would have shown from the beginning. Those you've tested, boB, might just be
from a manufacturer with wider selection range and also was there from the
factory line. A change would be more worrysome.

 

Bill Dorsett

Manhattan, KS

 

From: RE-wrenches [mailto:re-wrenches-bounces at lists.re-wrenches.org] On
Behalf Of boB at midnitesolar.com
Sent: Saturday, November 21, 2015 11:49 PM
To: RE-wrenches
Subject: Re: [RE-wrenches] module hot spots

 


I have looked at several modules (not SunPower though) and I see this much
temperature
variation between cells BUT I have not seen anything like your picture, with
only one cell
hotter.  What I have seen is hotter and cooler cells more or less spread out
semi-randomly.  Not sure if your example is normal or not for Sun Power ?

Here is one example from my library of FLIR pix.
A thermal imaging camera sure sheds light
on many different things !
boB





On 11/21/2015 9:31 PM, Marco Mangelsdorf wrote:

Hello all,

 

I'm seeing hot spots on some of the SunPower modules we installed circa
2007-2010.  (I've been a SunPower dealer since 2005.)

 

Sometimes theses cells are 20-30 degrees C hotter than the surrounding cells
and it's especially striking while using a Flir IR camera.  Check out the
two images below.

 

cid:image001.png at 01D12070.CBCC60D0cid:image002.png at 01D12070.CBCC60D0

 

Do many of you come across hot spotted mods?  Anyone know of any papers out
there on hot spots and the hit on performance and reliability?

 

Mahalo,

marco






________

 

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