Mixed Parallel and Series Solar?

Joined
Nov 18, 2022
Posts
198
Likes collected
244
Location
Holmfirth, UK
Funster No
92,520
MH
Elddis Majestic 135
Three 100W panels. Two connected in series and that unit connected in parallel to the third.
Is that a Truly Wonderful (Budget-ish) Idea to somewhat alleviate the occasional problem of shading while allowing reasonable output in weak lighting? And reasonable cables. Or not … ?
 
You can't do that, the two in series will be generating 44v and the signal one 22v. If it works it would work like two panels effectively losing the output of one.
You need to connect the series ones to a separate controller to the single panel.

The gain you get from series is so small better just to connect them all in parallel.
 
Oh no!
My Wonderful Idea crashes and burns!
This diagram from mowgli-adventures dot com seems to agree with you.
Annoyingly, I can’t understand WHY the overall voltage drops instead of increasing.
65CF4490-20B9-4B26-A80B-B5B14E69C788.jpeg
 
(Replying to myself)
Further trying to educate myself, I found this:
which goes even further in supporting Lenny HB 's answer.

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Certainly you shouldn't do as you planned, as it won't work as per lennies post above.
However I wouldn't expect the mowgli one to be correct. I would expect the voltage and current to be that of the series pair, the parallel one would effectively do nothing to contribute. Ie. Total current would only be 4.5A at 42.2v
 
It's not a perfect analogy, but look at it like water flowing down a river. The volume of water per minute is the current. The drop in height over the length of river is the voltage.

If the river splits in two parallel channels and rejoins, the amount of water flowing each route can be different and the total flow can be added together (add the current). But that drop in height must be the same (same voltage).

If one section of river is after the other in series, they might have different drops in height (voltage) but the amount of water that flows (current) will be limited by the tightest section. Also, if you clog one section (i.e put it in shade) it'll reduce the flow of all the sections.
 

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