Advice on installing large off grid system.

[Skypower]

I’d be leaning toward the Solark 15’s. Contractors like them and they are DIY friendly as the same time. Do allow for future expansion like a longer wire way for two more AIO’s and space for more batteries. I’m thinking that you’re going to be way light on energy storage with the size of your family. If you go with outdoor rated batteries try to mount them on the north facing wall in warmer climates like the California valleys have. Heat is the #1 life reduction of lithium batteries.

 

[Brucey]

I'm excited about it too, but I bet they will oof on state specific regulations like 18kpv is with some POCOs being really nasty about PCS certification. Or, maybe MidNite will not have a workflow ready for the states that need export limiter lock paperwork.

(Export limiter lock, EG4 has figured out, unfortunately every time they're tagged about PCS they think we're asking about export limiter. LeSigh. Presumably SolArk has ironed out all these processes)

Apparently it will be ul9540 listed when used in conjunction with their soon to be released rack mount and wall mount 5/14kWh batteries.

 

[zanydroid]

Apparently it will be ul9540 listed when used in conjunction with their soon to be released rack mount and wall mount 5/14kWh batteries.

Yes that is awesome but as we’ve learned from the 18kpv PCS problem that’s just the first few steps in a long compliance journey

 

[mp80]

That is a huge undertaking!
I'd start by taking a serious look for opportunities for downsizing and conservation. Every watt saved is a watt you don't have to produce.
Is selling off your kids legal in California?

I just wish they were old enough to help. Looking at appliances, heat pump dryers? Clotheslines in summer, wifey is going to love that one. I wish I had pushed to have a whole house fan instead of just HRV. My contractor was dissuading me saying it was redundant. But it seems its apples to oranges as far as the amount of air movement.

 

[mp80]

For those that are in California the code limits battery capacity to 80kw. What wasn't very clear was if that was for the whole residence or if it was for each possible location i.e. inside garage, exterior wall, separate building?

 

[Brucey]

For those that are in California the code limits battery capacity to 80kw. What wasn't very clear was if that was for the whole residence or if it was for each possible location i.e. inside garage, exterior wall, separate building?

Does that limit apply for ul9540 systems where a specific combination of inverter and battery is tested and approved?, ie solark+Pytes etc.

 

[zanydroid]

For those that are in California the code limits battery capacity to 80kw. What wasn't very clear was if that was for the whole residence or if it was for each possible location i.e. inside garage, exterior wall, separate building?

I don’t recall the details (I’m not interested in installing anywhere near that), but I do remember some AHJ’s ESS explainers clarifying this. Google for something like IRC + the code section number and PDF and you will find it.

I think the clarification was towards the generous direction

Note that you will need to go to AC/have separate system outside of each area anyway for the majority of 9540 systems, and for efficiency if using 48 V batteries

Does that limit apply for ul9540 systems where a specific combination of inverter and battery is tested and approved?, ie solark+Pytes etc.

Yes because you are only allowed to install UL9540 anyway.

 

[mp80]

How are you plan on doing heat and backup heat?

wood burning stove as primary 49k btu/hr, mini splits for 2 guest units

 

[mp80]

SolArk has AC coupling built in. It’s a feature of inverters.

Enphase and saving money aren’t what I would put in the same sentence. Look into 2 or 4 port microinverters (if you are considering Enphase for a small sub array) or Growatt hybrid/grid tie string inverter (if it is a big array and it was recommended to you due to reasons of bad contractor). If it is ground mount then you don’t need rapid shutdown (saves even more on the string).

What was the cost for grid connection? To compare with hybrid and ESS costs assuming it’s not rejected out of spite to PG&E. Also a lot of people here UNDERVALUE the ongoing maintenance and up front design overhead (which may involve multiple iterations to eliminate bad stuff from messing up requirements design or implementation) of being your own power company.

The enphase was already installed during the initial build process with the idea it was going to be grid tied. We've had to pivot to off grid so I have those on the roof already. Wish the contractor would have asked how I could spend the solar budget. PGE wanted 70-90k to bring it to my property no sure if that included a transformer or not. But at 0.66cents/kw for peak usage and climbing a couple times a year, (3 rate hikes in the first 4 months of the year) no thank you. It's not uncommon for people in my area to have 600-1200 monthly bills

 

[zanydroid]

The enphase was already installed during the initial build process with the idea it was going to be grid tied. We've had to pivot to off grid so I have those on the roof already. Wish the contractor would have asked how I could spend the solar budget. PGE wanted 70-90k to bring it to my property no sure if that included a transformer or not. But at 0.66cents/kw for peak usage and climbing a couple times a year, (3 rate hikes in the first 4 months of the year) no thank you. It's not uncommon for people in my area to have 600-1200 monthly bills

Ok the microinverters makes sense.

What is your plan for equipment fault tolerance and human maintenance knowledge fault tolerance? IE if you are no longer able to personally maintain it/hire people for that.

Your true replacement budget is the 70-90k grid connection minus the value of that fault tolerance

 

[1201]

Are sunny islands still legal in California?

4x sunny island, ac coupled to say 20kw of pv inverters will provide ridiculous surge capacity,and up to 44kw of day time capacity.

 

[zanydroid]

Are sunny islands still legal in California?

4x sunny island, ac coupled to say 20kw of pv inverters will provide ridiculous surge capacity,and up to 44kw of day time capacity.

OP is off grid, anything 1741 and 9540 is fine.

If they have to bail out and pay for a grid connection because all the electrical Microgrid expertise is lost then maybe an off grid only equipment is not so good. But that’s a big project in itself so maybe ripping out some storage inverters is of least concern. I’d be more annoyed to rip out the batteries if there is no 9540 compatible inverter for say proprietary batteries that are end of life fire sale specials

 

[1201]

OP is off grid, anything 1741 and 9540 is fine.

If they have to bail out and pay for a grid connection because all the electrical Microgrid expertise is lost then maybe an off grid only equipment is not so good. But that’s a big project in itself so maybe ripping out some storage inverters is of least concern. I’d be more annoyed to rip out the batteries if there is no 9540 compatible inverter

Even off grid has to be 9540?

 

[G00SE]

Quote was 160K with a 30K discount not counting solar credit

Im trying to keep total cost around 80k including paying the electrician, so maybe 65-70K of material and a lot of elbow grease

I think the equipment would be doable. Labor and accessories may get you in the back end idk.
Shooting from the hip, 2-15kw inverters seems solid. That provides 100a + of continuous AC power potential day or night and simple inspection considerations.
Solarks have a great reputation. I’m sure one could save a few Pennies if cross shopping other brands, at this scale it becomes an argument of “is it worth it?” Myself personally, while untested, would likely run at least 2 of the new Midnite AIO but many people would likely prefer to go a route of known success and little growing pains. Dual eg4 18kpv with accompanied power walls may be even more straight forward

I’d personally shoot for 6-8 of the batteries. I’d prefer user serviceable like a few racks of SOK batteries but code may not allow that where you are so I’d just pick whichever code approved option whether it’s eg4, ruixu, sok, etc.

Panels should be the easiest/cheapest part. Can buy 2 pallets of ~400w panels (60-72 panels) for under 6k now all day long.

Thats setting you back 50k in just inverter, battery, and panels. Add permits, racking, labor, wiring, breakers, fuses, SPD, etc to the end

 

[zanydroid]

Even off grid has to be 9540?

I don’t remember seeing any exemptions for that in the residential code. Why would there be? It’s still the same class of building

There is also a mental model is on what you can get away with. If you have existing habitation cert or local equivalent, and permitted solar panels, you can install non 9540 ESS and the only way they can tell is you mysteriously got more efficient or the batteries exploded and they found them during the fire investigation.

OP is doing a new off grid build. They will find a non compliant install without much trouble during the inspections

 

[zanydroid]

I looked at local installers and one wanted to use 2 sol-ark 15's, (5) 14.3kw EG4 powerwall batteries

This from the local installer is suspicious since I didn’t know EG4 was a battery partner nor 9540 combination. Presumably if the installer put it in and there is a permitting problem they eat the punishment.

But if OP copied it to a non turnkey solution and had issues , it is customer provided equipment so the buck stops with them to deal with this mistake.

 

[zanydroid]

Myself personally, while untested, would likely run at least 2 of the new Midnite AIO but many people would likely prefer to go a route of known success and little growing pains.

Maybe stock a hot standby of a known brand ready to change to. Possibly even premounted on the wall to hedge against the MidNite failing when the responsible family member is having, I dunno, appendectomy and not able to do the prep.

The standby does not need to be code compliant, just put it up after all inspections are done and dusted

 

[sunsurfer]

Are sunny islands still legal in California?

Do they inspire freedom, justice, Independence or portray the traditional family values? Then yes, they would be illegal.

 

[DIYrich]

Even off grid has to be 9540?

Ul 9540 is fire safety, so off grid has to also be compliant. Just like needing GFCI for outdoor sockets, whether on grid or off grid.