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Problem:

I have six 100 W panels wired in series on the roof of my van. I can only get 180 W maximum out of my entire setup (with a Canadian winter, I'm expecting at least 300 W), and I think the problem lies in them being in series. Someone told me that the panel with the least amps will bottleneck the entire system amperage output (which makes sense), so I'm looking for a way to increase my total wattage output by getting rid of this bottleneck. Two of my panels bend over the front of the vehicle, so they're great when my van is facing the sun, but they do poorly otherwise (thereby causing a really low amp bottleneck).

My plan:

I'm thinking of wiring the back 4 panels in series (grid_1), then the front 2 panels in series (grid_2), then wire grid_1 and grid_2 together in parallel.

My questions:

Does this series-parallel setup that I'm thinking about make sense for optimizing my total wattage output? I've also read that microinverters can work around this bottleneck issue as well, does anyone have any thoughts/experience with that?

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Your plan will not work.

If you wire 4 panels in series, the voltage is that of 4 panels.

If you wire 2 panels in series, the voltage is that of 2 panels. Half of that of 4 panels.

You are then planning to wire the grids of different voltages in parallel. Ain't gonna work. If you do that with batteries, the blue smoke will leak out. With solar panels at least there's some limitation of current so you may be able to avoid the smoke effect.

Every device or chain of devices connected in parallel must have the same voltage.

Also note that if you have an inverter, it may have its requirements on the input voltage. Thus, if you are going to modify the input voltage for example by wiring 3 panels in series and the a second similar series chain in parallel with the first chain, you will halve the voltage from a chain of 6 panels. The inverter may not like this halved voltage.

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    Ah okay, thanks for that. So I'd probably go with 3 sets of 2 panels connected in series, then connect those 3 sets in parallel. I have a solar charge controller between the inverter and the panels, but I'll still check in with the manufacturer of the charge controller before I change my setup. Thanks!
    – Otherness
    Nov 11, 2021 at 18:43
  • Also, in your second to last sentence, don't you mean that I'll have the voltage from a chain of *3 panels (not 6)? As in, if I have two chains of 3 panels each (in series), and I connect those two chain in parallel, my total output voltage will be that of 3 panels, right?
    – Otherness
    Nov 12, 2021 at 0:36
  • Yes it will be that of 3 panels (as opposed to that of 6 panels you used to have).
    – juhist
    Nov 12, 2021 at 17:46

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