Hello from Northern CA

[CVCPJared]

New to the forum, been stalking them off and on for maybe a year or so, finally made an account so I could participate

I installed an on-grid ~8kW roof mount solar on my current house maybe 2018ish? Fast forward to present day, we're building a house in the country on a few acres. Home needed a power pole and a few hundred feet of 4/0 wire underground, plus the CA required solar system on new homes that runs $10k but doesn't really save you much money. PGE runs over 50c/kWh now during peak and a steal at 46.7c/kWh off-peak, which really helps the ROI cutting the cord with them. Long story short, it wasn't that much more to just go off-grid and will save a ton in the long run. What could go wrong? Should be fairly easy and a blast!

Permits was a bit of a struggle. Originally I was told off-grid was "illegal per CA". I asked to see the code, a few days later they told me to get an Engineer's stamp and they'd approve it. Took many months to get the permits, but now finally ready to go!

I've got 40x 540w Canadian bifacial panels to ground mount (might do white reflective paint on concrete below and behind the panels, but that's for a future project), a pair of Victron Quattro 15kVA, planning to run parallel into an autotransformer for split 120v 100a lines to the main breaker, a couple of 450/200 TR MPPTs, 80x EVE LF280K to start with, going to run them 16S in 5 different banks with an REC BMS, with a Generac 26Kw as backup. I've got maybe 2 - 2 1/2 months to get everything all set up from bare dirt. I'm sure I'll run into issues and have lots of questions, and hopefully I'll learn from whatever mistakes I'm bound to make and I'll be able to be helpful as well

 

[timselectric]

Welcome to the forum.
Interested to see how you get all of this through inspection.
Especially in California.

 

[Ampster]

I am interested in what City or County building department approved DIY batteries. In the County of Sonoma I converted from DIY batteries to UL listed Pytes V5 batteries to pull my permit.
As to the "illegal to go off grid" question, at least in my jurisdiction, if a utility connection is available, you have to connect to it per the building code, but you do not have to use it. The connection requirement may vary depending on jurisdiction, but there is no way they can make you use it. There are fixed charges every month and they will be increasing in 2025.

 

[CVCPJared]

Welcome to the forum.
Interested to see how you get all of this through inspection.
Especially in California.

Thank you!

You and me both! They were a lot more interested in the battery shed than the panels, mostly related to fire. 16S battery units all need to be spaced 3 feet apart, etc. Something tells me the target is going to be a moving one

 

[CVCPJared]

I am interested in what City or County building department approved DIY batteries. In the County of Sonoma I converted from DIY batteries to UL listed Pytes V5 batteries to pull my permit.
As to the "illegal to go off grid" question, at least in my jurisdiction, if a utility connection is available, you have to connect to it per the building code, but you do not have to use it. The connection requirement may vary depending on jurisdiction, but there is no way they can make you use it. There are fixed charges every month and they will be increasing in 2025.

I gave them full plans, put the cell spec sheet, I've got stamped permits so Eve LF280K are UL listed. Victron is IEC only, not UL, so that was more a concern of mine. But there's something in the code saying counties are allowed to use equivalents. It never came up so I didn't bring it up lol. I included all the spec sheets in the permit, so again, fingers crossed none of that becomes a future issue

I'm in Stanislaus and that's kind of what they told me too, "if a utility connection is available", so unless you're in the middle of nowhere. They said that was CA building code and not theirs, but I found stuff online where Nevada county was assisting residents going off-grid to a degree and not just those on the side of a mountain, so I assumed it couldn't be in CA code. I read through hundreds of pages of code and couldn't find it, asked them to confirm and that's when they said I could move forward if I got a CA Engineer's stamp on the plans

 

[Ampster]

.....asked them to confirm and that's when they said I could move forward if I got a CA Engineer's stamp on the plans

Nice job calling their bluff. It is in the State code but the Counties or Cities have to adopt the State code and maybe Stanislaus has not officially done that.

 

[jjww]

Doesn't NEC require a minimum of 100 Amp service for dwelling? I seem to remember my inspector claim that...
Sounds like you have that with a pair of quattro's. odd they dont seem to care if you only have enough battery
for 1/2 hr run time...

 

[CVCPJared]

Doesn't NEC require a minimum of 100 Amp service for dwelling? I seem to remember my inspector claim that...
Sounds like you have that with a pair of quattro's. odd they dont seem to care if you only have enough battery
for 1/2 hr run time...

Yeah, we'll have 200a 120v service, split across 2 legs. They did mention I think wanting 100a minimum, and wanted to make sure basically that we would be able to power the well to run the fire sprinklers in case of a fire.

Sorry, I didn't elaborate much on the battery. It's 5 Batteries, each with 16 cells in series, each cell is an LF280K (280Ah, 3.2v, 896Wh), so ~71.6kWh on the batteries. Theoretical ~3 hours on max inverter with the sun down, but I that was based on the theoretical - heater blasting, well running, oven on full draw, toaster/microwave/coffee maker running, everyone taking hot showers, etc. - and I don't want the power flipping off and getting a look from my wife about the system I built not working Realistically I think (hope?) the batteries would last close to 24 hours without sun in most situations.