Not realy sure where to post this but here goes.
I’ve got 12 x 330W Canadian solar panels (about 6 years old) in 4 strings of three, running through a Smartsolar 150/70TR MPPT to charge my 3 x eTowers. I recently acquired another 6 x 600W JA Solar panels but I’m still in 2 minds where to install them. I haven’t bought the mppt’s yet and need to make up my mind before doing so.
The current setup is in green, all pointing North at roughly 38deg. My question is now this. Do I install 3 panel East and 3 West in the red squares or all 6 in the Orange square, also due North. If East and West each string will get a Smartsolar 150/45 mppt and if North, another 150/70TR. My Inverter room is almost directly underneath the current array with at most 8m of cabling to the MPPT. I do have more than enough space on my workshop roof (marked in blue) for the whole array but have this 100+ year old pepper tree that’s going to give me shading issues and I simply will not cut it down, oh yeah and I’ll have the issue of about 40m of cabling distance so would probably then have to swap the 150/70 for something in the line of a 450/200 which is k@k expensive. If going the E/W route I will get sun very early and very late, seeing that I’ve got very little shading issues. If going the N route, I’ll have to install it on a carport roof which is quite low and then I will have shading issues, esspecially in winter, caused by the neighbour’s house. I know some of you guy’s have played with E/W arrays with proper results. What do you suggest?
My only opinion here is, AVOID shading at all costs! When I relocated all my panels a few months ago, it was like a completely new installed system.
In winter, I had to get everything done before 14h00, thereafter my panels were pretty much non existent.
In summer, proper production only started at around 09h30. With the shade removed, I had almost full production capacity at around the same time and could pull my geyser from 07h00.
A West and East array makes no sense for me now as I have no shading. I have 100% SOC still at 17h00 currently and winter pretty much started - summer solstice being 21 June.
Invest in an EV. It will fix that little problem… 
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I have been reading up on yours as well as a member on the SA 4x4 forum with regards to your BMW I3 journey.
I am definitely considering an EV (read I really really want one!).
But this will only happen in about 5 years time. Who knows what will be available at that time at hopefully better prices.
Prices are coming down rapidly. Good for buyers. Less good for people who bought and kinda want to keep the resale up.
Volvo XC40 now around 700k.
EX30 touching 650k now. That’s Hilux money.
Ora 03 pretty consistently around half a bar.
Brand new BYD Dolphin around 540k, which means when they hit the second hand market a year or so from now, it will be under half a bar.
Mini Cooper SE around 400k now.
BMW i3 as low as 250k… but then it is getting quite old. You really want 2017 or later with the split EME/KLE setup.
This what my Pv yield, usage, etc looks like on a good winters day in the Karoo. This was yesterday. My geyser switches on at 11am though and I use my workshop equipment a lot through the day (200ltr compressor which runs a lot seeing that I use it on my cnc laser, 3 x 3d printers basically runs 24/7, Welding, 2 x car lifts used quite often, etc) so my usage are a bit rough. We are a family of four and the kids simply cannot get it in their minds to switch of lights and other equipment. I think I will be okay with the extra 3600Wp PV which would bring me to a total of 7560Wp. I plan on doubling my storage within the next 2 years though so that might become a problem again in future. I’ll see how it goes though. First want to get the new 600w’s on the roof and connected, preferrably before winter ends 
For me the benefit of extra panels is during poor weather. I recently did an upgrade and I now have power to throw away on sunny days. On overcast days I get better production and have less need to resort to the grid.
My panels are split, really N-ish and E-ish. The effect of this is that in the morning we get lets of power early on. The interesting thing is that the E-ish string can provide useful PV into the afternoon, about 14:30 at the moment.
We have settled into a routine whereby we use lots of electricity from about 8:30 to 13:00, and then not so much. Very little at night.
So think about your routine and when the extra juice would come in handy, or how you would like to be able to change your patterns.
Also how much battery do you have? I could probably get through to about 10:00 with our current battery and useage. If you have, say, 20kWh then maybe it’s better to point everything N, rely on the battery a bit longer into the morning and then get a big recharge in the middle of the day.
My hand is forced to a degree because most of my roof space faces E or W, there is only a small amount (6 panels max) facing N.
Shading? Or other reasons.
We’ve always had the N/E split on panels, so early on we settled into a “use it when you have it” routine.
