SOLAR: Does it ever end? Is it ever enough?

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If you remember I upgraded my entire battery bank in the spring (2025) and increased battery storage from 32kWh to 41kWh (630ah – 800ah) < click here >. I also went with a “closed loop” battery bank connected to my Victron CCGX. The Midnite MNPowerFlo5 batteries now control the charging vs the charge controller “smart network” and GX device. Other than me tinkering with the DVCC settings (which I learned my lesson not to) the system has been up and running with no real problems of any kind. Well, almost…

I did the upgrade in March…which is clear and cool weather with bright, clear, sunny, blue skies. Just about perfect conditions for maximum PV production. And then July came around. Here in AZ the monsoon season usually starts in July, along with cloudy skies, sometimes for 2 – 4 days in a row. So out came the generator to occasionally top off the batteries and/or keep the lights on. And that is also the time period when I started messing with DVCC settings. Yeah, bad combination.

A number of Victron experts on this forum helped straighten me out, educate me, and turn all the DVCC settings back to the defaults. Thanks guys!!

But, I still had a solar production problem. Yeah, I didn’t do a very good job of calculating the peak solar/sun times for each month…July – September can be the cloudy season, and I didn’t really account for that very well. I often couldn’t get the batteries up to a full SOC, sometimes not even close. Hence, the genset usage.

I am 100% off-grid and wanted the battery storage to carry me almost a week on my household “minimum load”; I achieved that with the 41kWh of batteries. But sufficient energy storage without sufficient energy production kinda leaves you us in the dark…no pun intended.

My system has “evolved” over the last 6 years. Finally settling on almost entirely Victron…smurf through and through! My PVs…well, a mess. I started on a shoestring budget and have pinched pennies since then when it came to PVs. Some would, rightfully so, criticize that…but that is just how it happened.

I had/have 3 arrays;

  1. 800w (8x100w HQST 18v/5.5a) mounted on my utility room roof facing south-south-east (165degrees), first array built,
  2. 2235w (6x250w Canadian Solar 30v/8.3a) + (3x245w Canadian Solar 30v/8a) ground mount facing south-south-west (210degrees), array built a year after the first,
  3. 2235w (6x250w Canadian Solar 30v/8.3a) + (3x245w Canadian Solar 30v/8a) ground mount facing south (180degrees), array built a year after the 2nd array.
  • Arrays #1 & #2 combined into a Victron 150/70. Array #3 into a separate Victron 150/70.
  • Arrays #2 & #3 evolved; they each started with the 6xCS 250s and then I added the 245s (3 each) last year. Yeah, not the best method, but close enough for me at the time.
  • Arrays #2 & #3 were all used panels, but I tested them and they were producing at 95% rated capacity…and I got a killer deal on them at the time.

Array #1 Upgrade –

I knew I had to increase production but the roof of the utility room limited me on the size of panels I could put up there. And my wife was severely limiting the upgrade budget as well. My solar business buddy gave me some used 175w Solar World panels (37.5v/5a) (tested out at 97%), couldn’t turn them down and they were a good fit for the utility room roof. I was able to install 6 of those panels for a production increase of 31% (2S3P) over the old panels.

Additionally, combining Array #1 & #2 couldn’t be a good thing; 1) different panels, 2) different compass points. True south for our location is about 170 degrees; #1 was spot on, #2 was 20 degrees off. I am sure the MPPT had “issues” trying to workout the charging algorithm making it inefficient.

So I purchased a Victron 100/20 MPPT Smart Solar Charger for Array #1.

Array #2 planned upgrade –

There wasn’t much I could do to increase production significantly at this point. But, I could remove the 6x250w CS panels and replace them with matching 6x245w CS panels. That gives me 9 matching 245w Canadian Solar (30v/8a) panels with no loss of production.

And since it will now be on its own Victron 150/70 MPPT Smart Solar Charger I should see more efficient, more production, out of the panels. Additionally, I will be painting the frame with all the panels removed and cleaning up some wiring.

Array #3 planned upgrade –

This array was the one place where I could increase production. So I will be removing all the panels, making frame modifications for another 6 panels, frame painting, wiring improvements, and panel reinstalling. I will then have a total of 15 x 250w Canadian Solar (30v/8.3a) panels on this array (3S5P).

And once again, since all panels will now be matching 250s I should see an efficiency increase there. And adding 6 more panels will increase the array by 1500w.

Projected Overall System Production Increase –

  • Additional 1750w in additional panels (plus another 1500w this winter)
  • Efficiency increase with the added 100/20 MPPT on Array #1,
  • Efficiency increase with matching panels on Array #2 & #3.

Current Project Status –

  • All of the work is done on Array #1, including the addition of the 100/20 MPPT.
  • Array #2 (phase 1) starts on Monday. Phase 2 will be this winter.
  • Array #3 starts the following week.

Watching the production side the last couple of days…yup, seeing more production with simply upgrading Array #1 so far.

Something New –

I was not happy with the array disconnect switches in the utility room. They just weren’t right for the job. So I came up with an “elegant” solution. Okay, maybe not elegant, but pretty cool IMO. I built a PV disconnect box. I integrated an appropriate sized circuit breaker for each array as the disconnects along with the SPDs.

Here’s the old set-up…
Here is the new set-up…
So each array has an exterior combiner box with fuses on each string, a circuit breaker for the array, and a Chinese SPD for the array. Then inside the utility room there is a circuit breaker (acting as a disconnect switch) and a Midnite Solar SPD. I like it!

One last thought…I looked and looked at Array #2 trying to figure out how to add substantial production capability to it. Location and spacing with the garden just wouldn’t let that happen. But I have another matching 6x245w CS panels…I didn’t want them to go to waste. I figured out that about 20’ away I can add another ground mount frame with the 6 panels and run them (3S2P) to the combiner box on Array #2. That will add another 1500w to the system sometime this winter.

Old production – 5.2kw

New Production – 8.5kw (when I am all done this winter with Array #2 – Phase 2)

So this is how I am upgrading the production side of the system…this time…and this winter. To me to just seems as if it never ends…it’s never enough. Oh well, the joys of solar, living off-grid…and evolution.

So…what/how has your solar journey been?

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