Which is better, Series or Parallel panels

I asked the same question of an engineer at Northern Arizona Wind and Sun as specifically applied to my 6 Kyocera 140W panels and Morningstar MPPT controller. He said that the parallel wiring was the most efficient in so far as partial shading of a portion of one or more panels or totally shading one or more panels for my installation. The down side is higher line losses and higher costs for heavier cabling.

Series if you have bypass diodes. And your pic suggests that shadows are approaching the rear panel where bypass diodes could also provide more power than parallel panels.

Look at the graph in this thread. Notice that from 8:18-10:18 shadows have reduced the panel output to 2/3 of 1 panel for the 3 panels. Parallel would be 0.

At 12:58 the output power is ramping up as the other 2 panel portions that were in bypass begin to produce full power.

And you can see how the MPPT algorithms are adjusting the output amps.

RJsfishin wrote:
I'm thinking batteries in series,....if I loose (sic) one, I'm done, finished, kadote.

Not at all the same thing. One panel is sufficient to charge.

The chances of a catastrophic premature failure of a well-maintained 6v battery are near zero.

Doesn't matter what it is now,.....pretend its nothing now.

I'm thinking batteries in series,....if I loose one, I'm done, finished, kadote.
In parallel I could still function w/ 1/3 less capacity.

Maybe S panels would be different, but I wouldn't know why.

No meaningful answer can be made with the information supplied. If it is an MPPT controller I'd lean towards series, IF there are lots of diodes to bypass shaded cells.

If it is pwm then you are hooped and must use parallel.

Hmmm.. well, I'd have to say parallel, without knowing what the diode characteristics of the shaded panel are.