Originally Posted by family wagon
The only somewhat uneducated comment I have is this: I understand some types of panels are susceptible to significant decreased output even if only partially shaded. (well, duh! SOLAR
) I got the idea that the current through the whole string dropped to the level of the few shaded cells, or some such awful thing. Roof vents casting a shadow on part of a panel mounted too close is supposed to be a big deal for example. Perhaps it was on https://handybobsolar.wordpress.com/
I read it? I don't recall.
Anyway, what I'm getting to is this: if you find it doesn't work out very well as-is, perhaps it could be because the pairs of panels on the left, top, and right have significant different sun exposures and so the whole string is dragged down to the performance of the pair least exposed to sun. Especially during winter when the sun is low in the sky. In that case, if you can find it in the cards to re-wire with three charge controllers, then you could re-arrange so that there are 3 strings on the left, 3 on top, and 3 on the right with each triple going to its own charge controller, then connect the controllers' outputs in parallel to the battery bank. This assumes the controller model is one that plays nice when wired in parallel with other charge sources. This way the panels could all perform to their best without impairing the performance of those with better exposure.
New update on my system.
I hadn't seen over 300w from my system until I stared running the a/c unit. As soon as I turned on the A/C power jumped from 300w to 1100w on my Midnite 150. I haven't tried loading the inverter with more then the a/c so it is possible that my set up could produce more.
I'm currently in Central Mexico with 1/3 of my panels pointing to the west, 1/3 pointing straight up and 1/3 pointing to the east. Roughly 45 degrees.
I also tested shading. When part one string is shaded the performance of that string suffers power loss but doesn't pull down the other strings. If I switched off the shaded string power may drop from 800w to 750w. My conclusion was that 50w shaded is better then 0w.
Check out our blog bellow for the photos of the build and our adventure south.