Mixed solar panel angles and/or shading in series strings or parallel?

[ericfx1984]

I'm building a small 3s4p array that will eventually be my secondary array

I am curious what the results would be if one of the series strings was at a different angle in the other three series strings.. or if one of these Siri strings was shaded ... Would the shaded series string draw down the entire array or would it only have a minimal effect?

 

[Bobert]

I'm building a small 3s4p array that will eventually be my secondary array

I am curious what the results would be if one of the series strings was at a different angle in the other three series strings.. or if one of these Siri strings was shaded ... Would the shaded series string draw down the entire array or would it only have a minimal effect?

My initial thought is No.No the shaded panels will not draw down the other strings ( unless something is wrong with them) and no the arrangement will not have a minimal affect. If you are using one MPPT charge controller the panels with lesser sun will not be operating at maximum power point and may in some cases produce almost nothing.

 

[wattmatters]

I am curious what the results would be if one of the series strings was at a different angle in the other three series strings.. or if one of these Siri strings was shaded ... Would the shaded series string draw down the entire array or would it only have a minimal effect?

A key benefit of having parallel arrays is that each series string can be placed in different orientations. e.g. one facing east, another facing west, or one string tilted a lot, another string pretty flat. Or any combination thereof. Just keep panels in the same string facing the same orientation.

Similarly, the performance of one string experiencing shade will not affect to any noticeable extent the performance of the other parallelled strings.

The MPPT will settle on the voltage which generates maximal power output from the entire system, and all that happens is the shaded array just doesn't supply much current to the parallel circuit.

 

[efficientPV]

It would be better if each string saw the same amount of sun ant any time to have at least one strong string. Usually about 3/4 of my 2S6P panels are shaded at any one time and I do quite well with that arrangement. It does produce power in ambient light conditions.

 

[Bobert]

It would be better if each string saw the same amount of sun ant any time to have at least one strong string. Usually about 3/4 of my 2S6P panels are shaded at any one time and I do quite well with that arrangement. It does produce power in ambient light conditions.

Or use separate charge controllers on each string if you have the $ or the math works just right for you

 

[efficientPV]

Multiple charge controllers work well for bulk charging. I've actually found multiple charge controllers work like crap together if they can't communicate together.