C solar

Rudolph a North only system does indeed deliver quite a bit more yield than E, W and N. You have the benefit of a good spread over the whole day. If you mention that having more PV during midday and wasted you are already wasting a lot by having a 15kwh bank fully charged by 10h. You might think of using a deeper discharge during the evening. It sounds as if you don't really need the boost from the W side just prior to sunset if batteries remain fully charged from after 10h each day.
Obvious I don't know what your profile is it is based on what I figure out based on details provided.

Hi Clinton @C solar
I like what you've done with your maximum theoretical production curve. What's the total area under the "combined production" curve (total theoretical daily production) for such a system?
I think the ideal setup (with 16 panels) would be an East string (5 panels), a North string (6 panels) and a West string (5 panels) with the East & West panels paralleled on the one MPPT and the North string on the other MPPT (basically what you proposed in your theoretical calc). I actually think that this setup would produce a greater daily yield (in a typical home) than a system with all panels facing North. An East, North & West string split will tend to "flatten" but "widen" your daily production curve as you start producing earlier in the morning (East string) and produce until later in the afternoon (West string). The peak production around midday (predominantly North string) would be compromised but in my experience, we won't use the full production capacity during midday of an all north facing setup. Typically, our house would only use a maximum of around 6kW at any moment so a system that can deliver 8kW would be wasted capacity. I would rather have a system with a maximum production capacity of 6kW but with the "extra" 2kW capacity available for use in the late afternoon (when we are cooking or bathing the kids). This means we start drawing power off our batteries later in the afternoon.
On my system, during the summer months, my maximum daily consumption is much less than in winter which means that I probably only use between 40% and 50% (estimate) of my system's full installed production capacity. On most summer days, my geyser is warm and my batteries (15kWh) are full at around 10:00!! The benefit of being "overspec'd" on production capacity during summer is that we tend to have many cloudy or rainy days so with the extra capacity we always manage to fill up the batteries and warm up the geyser. You might only have 3 or 4 hours of sunshine on some days but with your production capacity spread over 3 directions it doesn't matter when you get some sunshine.
This has become a really interesting discussion!
Regards,
Rudolph
 
 

Hi Rudolph @Freakazoid,
I couldn't resist. Here I took your december MPPT 1 curve , and mirrored it as a theoretical MPPT2 facing West & North (mirroring your current eastern panel setup) and overlaid the two of them .The white (and black lines) shows the combination production curve. 

I reckon this April setup might deliver about 64kWh for the day.
This setup looks optimal for long productive sun hours.
What do think?
C

Hi Rudolph @Freakazoid,
If this blue curve is typical for a sunny day on your Mppt 1, then I'm surprised and impressed.
      1) Its a wiiide steady curve with strong production early in the morning already.
      2) In April you are getting very close to the 4kW (+-) upper limit of your Mppt for a good wide chunk of the day.
      3) It appears as though the two string directions is actually not affecting your Mppt's production bad at all. It actually looks benificial...

Would love to see a December curve on this blue Mppt. Guessing you are producing close to 30kWh/day on a sunny December day?
Fascinating!

Compare your april curve above width mine below from a few days ago.: