[RE-wrenches] Shade Mitigating DC Device Application

[Matt Lafferty]

Esteemed Wrenches,
 
Your collective wisdom & conjecture is sought in resolving the following
riddle:
 
There once was a home in the hills.
With morning sun the roof is filled.
Blasted mountain rising in the west,
Makes a shady mess at very best.
 
"Onward! Fear not!", sayeth the man.
"Twenty-four modules. Not one less!"
"Black box of magic for every one."
"And string inverter plus Island of Sun!"
 
With fifty-one hundred watts of DC.
Two series strings of four times three.
Black boxes of magic, but not by that name.
At quarter the price are they really the same?
'Tis not the matter, least not today.
To you the group... What do you say?
 
For greatest performance over time to yield...
2 balanced strings of shade and of sun,
Or put worst shade all onto one?
Snake-oil merchants say not to worry.
Magical boxes change dark to light in a hurry.
What say ye, from out in the field?
Balance the strings, or not?
<End>
 
Some factors to consider.... The site is shade-challenged, primarily in the
afternoon. There will be two strings of 12 modules each feeding a single
inverter. Enphase is off the table for now. Homeowner specifically wants to
do back-of-module DC shade mitigation. The array layout is such that
configuring the strings so there is a dominant sunny one and dominant shady
one is possible. It is also possible and almost as easy to configure the
strings so they are more balanced with each other. Assuming that each module
is equipped with a black box, will it make any difference which
configuration gets used?
 
I have my theory on the subject and am interested in yours. Thanks in
advance for any and all feedback. 
 
Pray for Sun!
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