AC coupled battery supplying essential sub panel with Grid tied Micro inverter - Wiring question

[mufasa]

I am getting ready to add another 7k of solar to the house for more EV charging and to switch the house over to more electric and get rid of Natural Gas heating.

Wow +7Kw. I guess my system is still undersized for what I want to do.. running out of usable roof space..

Nobody told me diy solar is a gateway drug to more spending! The grid zero dream is a very tempting drug..

 

[Ampster]

So right now my plan goes like this:

Main panel ===== surge load panel === outback === essential panel === PV
|======== pass through ========|
|== Future EV charger
|== Table saw

My Skybox is configured similarly. I don't know what surge load panel is. Mine looks like this.
Main Panel=====Skybox==== Critical (essential) loads panel====AC coupled PV
I am grid tied and I have EV chargers and AC loads on Main Panel. Some of my AC coupled PV is IQ7s and some is Solaredge GT inverter. I also have other PV wired to Skybox (DC coupled).

 

[Ampster]

Nobody told me diy solar is a gateway drug to more spending!

As the famous saying goes, "You can pay me now or you can pay me later." In my case, the pay me later option is PG&E, and I preferred to invest now to give me a hedge against inevitable inflation.

 

[mufasa]

My PV combiner and essential panel is in garage, and the main panel is on the other side of the house, connected via a 50ft 2224 ser cable.
And I also want some high load device in the garage, which after many answer points out, is not suitable for essential panel.
So I plan to add a surge load panel for EV charger / Table saw, before the outback so that I can avoid putting these high load device behind the inverter.

 

[mufasa]

As the famous saying goes, "You can pay me now or you can pay me later." In my case, the pay me later option is PG&E, and I preferred to invest now to give me a hedge against inevitable inflation.

I totally get you. PG&E have been raising price happily over the year, and throw in a few brown out each year as a extra fxxx you.

Will wait till next april, I got this solar in for one year to decide how many panel should be added..

I am looking at friends in Santa clara city, enjoying their public held utility with low price and stable power.
When can we have public utility everywhere? Privately held utility just does not seem to work when revenue goes to ceo bonus, dividend instead of grid maintenance.

 

[Ampster]

So I plan to add a surge load panel for EV charger / Table saw, before the outback so that I won't put these high load device behind the inverter.

Yes, that technically is how mine is wired. The great thing about the Skybox is that you can buy external CTs and wire them at your Main panel and your surge loads will be supported by your Solar before going to grid. There is a good thread on that topic on the Ouback forum. I have same handle there.

 

[mufasa]

Cool.
I still have not clip on my enphase CT to the main panel... that place is full of wire now, I was planning to clip it on after I move some circuit to make space.

Maybe I should read a bit more about how that CT works and decide which CT should go to the main panel -> meter wires.

 

[Ampster]

Cool.
I still have not clip on my enphase CT to the main panel... that place is full of wire now

I was talking about the CT for a future Skybox. If you have CTs for the Envoy you can have consumption and production monitoring. I am a retired CFO so I like lots of data. Thatvis another pro aboutvthe Skybox. Lots of data from the internal web server.

 

[mufasa]

I am a sysadmin so I like lots of data too. Even before Solar I got a rainforest eagle to pull consumption data off smart meter and log it to display from grafana. Even with that I still get 2 enphase CT.
Now that you mentioned yet another CT to pull data. Maybe Skybox will have a local API so I can pull data out locally too..
you can see how much I like data : )

 

[Ampster]

I also have a Rainforest but I am not facile with APIs. Are your micros wired to sub panel yet? That will free up breakers on main or surge panels.

 

[mufasa]

Not yet. It won't free up any though. Currently combiner goes directly to main panel, via a 6-3 romex, and a 2224 SER pulled to mbp already, waiting to be connected.

I probably will keep simmer on this plan, refine the detail and finally connect the two garage panel later this year, when I got most parts in. Then the rewiring starts..

 

[Hedges]

I am looking at friends in Santa clara city, enjoying their public held utility with low price and stable power.
When can we have public utility everywhere? Privately held utility just does not seem to work when revenue goes to ceo bonus, dividend instead of grid maintenance.

They were paying $0.07 when we paid $0.15
But will they be permitted to continue burning natural gas in their turbine generator?
Plan elsewhere in CA is to shut down fossil fuel plants.

 

[svetz]

...There are no AC batteries. It just isn't possible....

The term AC Battery has been in the vernacular for a while now, not sure who coined it. Have to love marketing types! As it refers to a class of products sold as that classification, I hope most people will understand what I'm talking about.

At a minimum, it seems to be a battery, inverter, and charger. An AC battery for grid backup (e.g., Tesla, Enphase) must also include in the "system" an ATS to prevent back-feeding the grid. Both Tesla and Enphase have those and are also capable of controlling microinverters. Additionally, Tesla's system can also work with a variety of string inverters.

I believe (not sure) that Teslas controls the microinverters like most AC coupled solutions do (relay that disconnects them). The Enphase system talks to the microinverters via ethernet over powerline and tells them what to throttle at. I've heard Victron can make use of UL 1741 (frequency shifting) to throttle them, one of the members here reported they have just started testing will hopefully post their findings). If so, that means it should be able to throttle any UL 1741 compliant microinverter/string-inverter.

Not sure how you are saying there are only 2 solutions: Two solutions that fit the OP's situation? Two AC coupling solutions? Two with transfer switches?

If you know of other technical solutions beyond (1) AC battery systems designed to manage microinverters (i.e., Tesla, Enphase), or (2) AC Coupling (e.g., Skybox, Sol-Arc, Schneider) I'd love to hear about them!

 

[Ampster]

When I Google the term "AC battery" I get things like Jackery and similar products. Those products are not capable of AC coupling with GT inverters.

I never heard the term "AC coupling" before the UL1741 spec was developed in 2010. Until then, GT inverters just followed the grid frequency. I had a Xantrec GT inverter built in 2008 and it did shut down if the grid voltage went above a certain number. Perhaps it had a minimum voltage as well. I did not pay attention to the details then.

 

[Ampster]

Plan elsewhere in CA is to shut down fossil fuel plants.

I have not seen that plan. I have seen Renewable Portfolio Standards that have goals of ever increasing amounts of renewable energy. A goal is not a plan but goals inform plans. I remember Eisenhower's quote on the eve of the Normandy invasion, "Plans are nothing, planning is everything".

I have seen fossil fuel plants retired because they were cooled by ocean water. I have also seen at least one of those plants replaced by a combined cycle plant. I have also seen peaker plants retired because they cannot compete economically with short term battery storage. Coal generation has definitely been retired because of economics. No doubt, we are in a transition but natural gas generation will be around for a while.

In California the generation of electricity is for the most part not owned by the Investor Owned Utilities. It was sold during deregulation 20 years ago and is owned by companies like AES, Calpine, NRG and others. How those companies plan to shift their mix of generating assets may be influenced by statewide goals but i have not heard them articulate a strategy of shutting down their fossil assets. Yes some have invested in battery storage. Most of those companies operate nationally and in some cases internationally.

 

[Hedges]

California faces a crossroads on the path to 100% clean energy

With a 2020 shutdown deadline looming, four coastal gas plants have become an early battleground in an increasingly urgent debate.

www.latimes.com

"But natural gas, a planet-warming fossil fuel, still generates one-third of the state’s power — and officials don’t yet have a plan for phasing it out."

OK, they don't have that plan yet.


Construction equipment is privately owned too. Older equipment has already been or is being made illegal, so the plan to shut them down is already in motion. An underground contractor I know will retire rather than buying newer replacements.

Perhaps NG plants will be permitted to operate under "cap and trade" for a while, then eventually shut down.

 

[Ampster]

An underground contractor I know will retire rather than buying newer replacements.

That is a choice he is is making because he does not want to invest in cleaner and more efficient equipment. Some young guy will invest and be sucessful. The young guy will probably be using newer laser survey equipment attached to every excavator bucket too. It is just part of the transition. Same thing happened to buggy whip manufacturers a hundred years ago. Some of the rules have to do with air pollution. I grew up in LA when you could not see City Hall because it was so smoggy. I am in favor strict air polution rules.

 

[Hedges]

Yes, he is near retirement, so not worth buying a new fleet.
Traditionally, people may start out with used equipment, buy new as they become more successful.
Likely there will be a consolidation to fewer large companies performing heavy work since everything must be recent models going forward.
This particular contractor has already stopped doing government or public utility work, due to the extra paperwork required documenting that he isn't violating labor laws. "California. The climate is right. For business."

I like clean air too.
High registration fees for portable diesel generators isn't about clean air. If anything it is a sin tax.
A car dealer to imported and retrofitted emissions systems on non-California cars was convicted. Not for emissions, which were within limits, but for paperwork. The government had not issued paperwork allowing these models.

Not sure to what extend other blends of fuels might make existing diesels cleaner. Or feeding them 75% propane, with diesel for timing and ignition. I'd rather see economical retrofits.

 

[WildLeg]

If you want to DIY an Enphase Ensemble and Encharge system you will need to put yourself through the Enphase university program. It’s free and some parts are dense others short and simple. After the training you will need to follow a design review template. Full certification would involve hands on training. Pricing has decreased recently and the lowest pricing can be found at the Enphase store.
https://www4.enphase.com/en-us/certification-support-program-guidelines https://store.enphase.com/storefront/en-us/