Parallel Solark 15k, no interconnect agreement.

[zanydroid]

so all I can say is that my interconnection application allows me to enter in any piece of equipment but it also states it must be California rule 21 compliant among other certifications which all compliant equipment is on the California Solar Equipment list. I was just looking and there are zero Growatt inverters listed unless it’s under another name.

My screenshot above of the CEC equipment list shows it as Shenzhen Growatt ..

 

[629658]

I cannot find your inverter model on the list so I don’t know but my gut says you’re going to hit a wall with your selected equipment. I almost certain your inspectors are going to have an issue with that auto transformer but I have been wrong in the past.

 

[629658]

My screenshot above of the CEC equipment list shows it as Shenzhen Growatt ..

Yes I found the company and their California approved inverters but your model number is not on there as I can see

 

[zanydroid]

Yes I found the company and their California approved inverters but your model number is not on there as I can see

Hmm, OK. In that case maybe anyone that buys Growatt from Renvu should have Renvu do the full thing - plans ready for PG&E and AHJ, full parts list, etc. Then it's 100% on Renvu if something goes wrong with suitability for use in California (esp since Renvu corporate and warehouses are all in PG&E territory).

 

[ImAnIdiotPleaseBePatient]

It's for a separate project I'm thinking of doing next year, not related to this grid-tie project.

I might get a single 120V UL-listed hybrid inverter rather than two (to save money / space), for emergency grid-down power. And then use an Auto-transformer to AC couple my existing microinverters to it. It's obviously not possible to directly couple these 240V microinverters onto a 120V inverter, and in grid-down situation I cannot use the utility transformer to do 240V->120V step-down from the microinverters

Growatt makes a UL listed transformer, for use with battery backup systems for sure. Pairs with the MIN inverters, and can do full house backup with ark batteries. Not sure if you can use it for inverter only though. It also has a breaker and a smart meter, and it costs a fortune, but it may work as an alternative.

 

[Hedges]

Somewhere I thought I recently read that if neutral of an autotransformer is used, it must be tied back to neutral of the source.

I just scrubbed through the CEC lists pretty quickly and only the "main" unit of the Growatt system is listed, namely the hybrid. I don't see the transformer as separately listed.

CEC listing shouldn't matter for transformer, only for the inverter.

Don't rely on the CEC web page to see if inverter is acceptable. PG&E just rejected my older model TriPower.
Open the Excel spreadsheet from CEC web page, which has additional columns. There need to be "Y" for some additional features, required as of 2020.

Cost for utility transformer installation?

What has the utility company charged you for a transformer installation or upgrade on their side of the meter? How flexible/negotiable were they? I have a house in Oakland, CA. with 100A service. To support the PV install I want to do, and for more loads like electric heat (presently all gas)...

diysolarforum.com

As I said I think randomly adding an AT that's not in a manufacturer's SLD is a recipe for great sadness, esp if you need the AT active when on-grid to make your system work.

If he has a 120V inverter and wants 120/240V split-phase, I think an auto-transformer should be fine. So long as well behaved, not drawing excessive current. That won't have the same issues as trying to derive a neutral while on-grid.

 

[zanydroid]

Somewhere I thought I recently read that if neutral of an autotransformer is used, it must be tied back to neutral of the source.

Hmm.... I was thinking today actually about how to ground the AT neutral when AT is used to balance stacked split phase inverter set up in grid assist mode. If you bond it back to the MSP ground there may well be current on that all the time. If you drive in separate set of rods, but the grounding systems are not strictly isolated, there will still be stray current across wherever the two systems accidentally touch each other (EG EGCs going into the same metal box or metal conduit).

 

[629658]

As previously stated AT will not pass inspection for grid interconnection. I didn’t say it wouldn’t work but a utility will not allow parallel generation using an AT. No more than allowing a single phase generator to be attached to the grid to sell back their power generation. Nope no way. I don’t live in California and they comb through the application. Everything and I mean everything has to be correct down to the signage colors and wording….exact. In my instance, here in Illinois, if it’s not Generac or Tesla ESS they think it’s alien technology and really put it under the microscope. If I threw in an auto transformer they would call in the National Guard.

 

[629658]

As previously stated AT will not pass inspection for grid interconnection. I didn’t say it wouldn’t work but a utility will not allow parallel generation using an AT. No more than allowing a single phase generator to be attached to the grid to sell back their power generation. Nope no way. I don’t live in California and they comb through the application. Everything and I mean everything has to be correct down to the signage colors and wording….exact. In my instance, here in Illinois, if it’s not Generac or Tesla ESS they think it’s alien technology and really put it under the microscope. If I threw in an auto transformer they would call in the National Guard.

Utilities are not science labs zero experiments. Unless it’s UL, NEC and proven it’s not going to be allowed onto their infrastructure.

 

[Hedges]

Hmm.... I was thinking today actually about how to ground the AT neutral when AT is used to balance stacked split phase inverter set up in grid assist mode. If you bond it back to the MSP ground there may well be current on that all the time. If you drive in separate set of rods, but the grounding systems are not strictly isolated, there will still be stray current across wherever the two systems accidentally touch each other (EG EGCs going into the same metal box or metal conduit).

And here it is mentioned:

Safe Grid Use of the 5000ES and transformer

Are those wires from the inverter? Autotransformer conductors.

diysolarforum.com

No more than allowing a single phase generator to be attached to the grid to sell back their power generation. Nope no way. I don’t live in California and they comb through the application.

20 years ago, GT PV inverter had only L1/L2/G. That's 240V single-phase generator.
Today, required to have N connection. But that doesn't carry current, is just used to check voltages are in spec. [edit, I thought, apparently not]
SMA wrote an opinion that neutral wire ought to be acceptable same gauge as ground, which also carries zero current except during fault. (rather than same gauge as L1/L2.)

Enphase is 120V, single-phase generator. Do they require distribution across two phases? [edit, not correct]

Earlier small Sunny Boy (700W etc.) were 120V, but later/larger were 240V. Something about utility not wanting imbalanced generation.

If I threw in an auto transformer they would call in the National Guard.

Make a system that works without needing neutral, e.g. load is 240V air compressor, wait until you can't see their tail lights anymore?

 

[Ampster]

Enphase is 120V, single-phase generator. Do they require distribution across two phases?

Enphase is 240 volts using two hots and no neutral.

 

[629658]

If you think back it literally took an act of Congress that forced utilities to accept Solar generation in the first place. If not for that there still wouldn’t be solar. So the same goes for AT parallel generation. I wouldn’t hold my breath. And yes you could do many things to sneak it in but if ANYTHING goes wrong ANYTIME your on the hook, going to have your meter pulled at the least and/or get a big bill from the utility and a denial from your insurance company. So my question is why? There is plenty of compliant equipment to install. Save a few bucks? Really? Spend a dollar to save a dime? So let’s look at the difference between a $4000 inverter and a $7000 inverter. After FTC $2100 difference amortized over a 10 yr life cycle $210/yr $17 per month. Seems like a no brainer to me. I’m all for saving money but this is no area to go cheap IMO.

 

[Ampster]

Today, required to have N connection

Just to clarify. it depends on what part of the system you are referring to. As I pointed out, Enphase has no neutral when it feeds into my panel. The panel that feeds the grid has a neutral.

 

[Hedges]

Maybe at the whim of utility or AHJ?

I don't find anything about requirements in manual for current model Sunny Boys, just "If there is a neutral conductor, connect the neutral conductor to the terminal block in accordance with the labeling."

From the old SB 5000US manual,

"Automatic Grid Voltage Detection
The Sunny Boy automatically detects the grid voltage that it must feed in. Depending on the voltage
and the phase angle between L1‑N and L2‑N, the inverter determines whether it is connected to a
208 V, 240 V, or 277 V grid. If the Sunny Boy is configured for the wrong grid voltage (for example,
the inverter was configured for 240 V and then connected to a 208 V grid), the Sunny Boy displays
an error message.
...
If the power distribution grid uses a neutral conductor, the responsible authority can demand that a
neutral conductor be connected to the inverter."

With neutral connected and jumpers set for auto-detect, it recognizes which grid configuration.
Without neutral, jumpers must be set for the particular configuration.

This could be useful to me if I put SB on load panel and fed it either 120/240V from grid or two legs of 120/208Y from a 3-phase inverter.

 

[zanydroid]

Today, required to have N connection

Hoymiles and Enphase GT microinverters will out of the box work with only 240v wiring. You do not need any additional hardware with Hoymiles for installing compliant with manufacturer instructions. With Enphase you probably officially need to add the controller box which likely only uses neutral to power the controller.

There is absolutely no way Enphase micros are using the neutral for any kind of active interaction with the grid even if the controller has a neutral connection. There’s simply not enough data bandwidth between the controller and micros for that.

 

[67BGTEV]

Hmm, OK. In that case maybe anyone that buys Growatt from Renvu should have Renvu do the full thing - plans ready for PG&E and AHJ, full parts list, etc. Then it's 100% on Renvu if something goes wrong with suitability for use in California (esp since Renvu corporate and warehouses are all in PG&E territory).

Deleted

 

[Swift Father]

Going to have two brand new Deye 16k's for sale here in a month or so ?

I am interested.

 

[Danke]

so all I can say is that my interconnection application allows me to enter in any piece of equipment but it also states it must be California rule 21 compliant among other certifications which all compliant equipment is on the California Solar Equipment list. I was just looking and there are zero Growatt inverters listed unless it’s under another name.

Is your Victron Power In listed?

 

[ImAnIdiotPleaseBePatient]

I am interested.

They are on the forsale/trade section. I finally got US tracking after two months, and it says it will be delivered on the

I am interested.

Well, I have the US tracking info. It was supposed to be delivered on the 23rd of this month, but the label was created a week ago and it hasn't been dropped off with fedex yet. I just extended the time on Alibaba and messaged the company I bought it from. Hopefully it makes it :|

 

[629658]

Is your Victron Power In listed?

No I don’t think it’s UL.