Separate solar string facing different directions on a single charge controller

Cuteajax

What will be the effect if I combine separate solar strings facing different directions on a single charge controller? Will I get the average of both outputs or less? The orientation of my roof can only allow me to separate my arrays. Please advice. I have 6 units of 330 watts solar panels and a single Midnite Classic 200 charge controller.

RCinFLA

It will be a compromise on both direction panels.  Sometimes less net than one optimized direction only, especially if any shading on one direction's panels.

Better to have separate controllers.

BB.

Vmp of a solar panel is based on design (number of cells in series, specific chemistry and construction) and based on cell temperature.

There has been an "argument" in years past... An East vs West facing array--The temperature of the cells are different (in AM, East array cells are hotter, in afternoon West facing cells/panels are hotter)... So you end up with two different Vmp-array values that shift over the day.

One mfg.'s white paper said at the time, the difference between two array planes was not enough to make a difference (we say two panels with Vmp-spec difference of 5% to 10% are "close enough" for government work). And we have a "retired" member here with lots of large MPPT system design experience and multiple arrays with laboratory grade power loggers that said that in his experience, that two different array planes need separate MPPT controllers (or separate MPPT inputs on newer equipment) to optimally harvest from the arrays...

With two different Vmp voltages, you have two different "peak" Vmp-array voltages and there is no one point where Pmp=Vmp*Imp has a single optimum solution--You have (at least) two different peaks and it is not always clear which peak an MPPT algorithm will capture (it may capture the "lower" peak)... More modern MPPT controllers (like Midnite) should be better at finding and tracking the "best peak".

In general, you should not damage anything with two planes and one MPPT controller... Typically I would think it is better to have Plane A with its series connections, and Plane B with its series panel connections--And to not have some Plane A panels in series with Plane B panels... Solar cells go "high resistance" when dark (or at least less light than their series neighbor).... Not a good idea (less power, possible overheating of bypass diodes in panels, etc.).

Found one 11 year old discussion with dead links and a quote:

https://forum.solar-electric.com/discussion/6583/poor-mans-tracking-splitting-arrays-on-one-charge-controller

And "Guppy's quote" from original post:

https://forum.solar-electric.com/discussion/comment/60858#Comment_60858

And member Dave Angelini years past has said that need to also understand how multiple plane arrays and clouds passing overhead are difficult for MPPT controllers to track Vmp-array successfully.

-Bill