8400w Grid Tie System - Kit or piece it together?

[foo1bar]

Yes but if you have a problem in that particular inverter (unless it is catastrophic) you will not know it maybe for months or years. The panel output reporting could look normal but actual inverter output could be abnormal without anyway of knowing.

I think the vast majority of failure mechanisms with inverters are going to be noticeable on a stand-alone inverter.

I don't think you are likely to get a case where one of a pair of inverters is 3%-15% lower than it should be. (less than 3% and IMO you still won't notice when comparing to the other - more than 15% and you would notice it even if it were standalone.)

I am a big fan of per-panel trackability. For a large installation that I represented the nonprofit, I found an installer hadn't hooked up one of the modules that way (190 modules; only 189 producing power)
But in the OP's case, he will have 24 modules with 2 or 3 strings, minimal shade, all the same orientation/tilt and no requirement for rapid shutdown. In that case I think a regular string inverter is the more economical choice. Of course if he wants to do Solaredge for the entertainment value - I certainly could understand that.

If I were the OP, I might consider doing a ground-mount like bcroe has, with east and west oriented panels, providing more total power, while still fitting in the POCO's 10kW max restriction. Doing things that way could give you heat cheaper than propane delivery

[ButchDeal]

But in the OP's case, he will have 24 modules with 2 or 3 strings, minimal shade, all the same orientation/tilt and no requirement for rapid shutdown. In that case I think a regular string inverter is the more economical choice. Of course if he wants to do Solaredge for the entertainment value - I certainly could understand that.

In OPs case he wants to be able to add more Solar modules latter and will be limited by 10kw AC. SolarEdge allows easy string configuration and mixing pv modules which will be the case as finding matching pv modules years down the road is nearly impossible.

[Mr4btTahoe]

Well... had a bit of a mishap/setback... but it's working out for the best.

Things went south during tree removal... tree service dropped a tree and the wind caught it before it started to go. Tagline snapped and it went a ways off where it should have... ended up ripping the electrical service out of the shop.

Their insurance is covering it.. so no harm.. no foul.

My electrician came out and discovered that the main service feeder isn't up to code nor is the meter base.. and the "electrician" that installed the drop to the shop was apparently smoking some good stuff. Anyways, my electrician says everything has to be brought up to code to do the repair... so their insurance is covering a new 325a meter base/breaker-disconnect box along with dropping the proper size line in the ground out to the shop. While we are at it, I'm going to go on and upgrade the panel in the shop too.

Anyways... electrician is 2 weeks out but everything will be up to snuff and ready for the solar system after that... and it didn't cost me a small fortune.

[Mr4btTahoe]

All is back on track. POCO is coming out sometime next week to inspect the main line from the pole to the service entrance to verify it will carry the new service.

Electrician is coming out after to install the new 400a service drop and 100a feed to the shop. I'm going to go on and have him install a new 100a panel in the shop and make sure it is grounded properly and such... along with adding the 40a disconnect for the inverter. That way, all of the AC side will be done by an electrician and be up to code.

I'll be placing my order with Renvu by early April.

SOO ready to get rolling on this. Getting ready to start the application for interconnect with the POCO.

[J.P.M.]

All is back on track. POCO is coming out sometime next week to inspect the main line from the pole to the service entrance to verify it will carry the new service.

Electrician is coming out after to install the new 400a service drop and 100a feed to the shop. I'm going to go on and have him install a new 100a panel in the shop and make sure it is grounded properly and such... along with adding the 40a disconnect for the inverter. That way, all of the AC side will be done by an electrician and be up to code.

I'll be placing my order with Renvu by early April.

SOO ready to get rolling on this. Getting ready to start the application for interconnect with the POCO.

I'd get the POCO and others' OK to the design and the implementation plan before I bought anything.

[foo1bar]

I'm going to go on and have him install a new 100a panel in the shop and make sure it is grounded properly and such... along with adding the 40a disconnect for the inverter. That way, all of the AC side will be done by an electrician and be up to code.

I would have him install a panel with a 200A busbar, but with a 100A breaker feeding it.

Probably less than $100 more and will make it easier to expand your solar system later on if you want.

[Mr4btTahoe]

I'd get the POCO and others' OK to the design and the implementation plan before I bought anything.

Spoke with the sole person responsible for interconnection with the POCO a few weeks back. Good to go there. Sent in my application already. Also already spoke with the county building inspector.. good to go there as well.

-Foo1bar-

As far as changing to a 200a panel... possibly. The electrician is coming back out Monday to take a peak at the panel in the shop.. will replace it if needed. I'll run it by him and see what he says. I already have the insulated tap fittings.. and I can't really go any larger then what I'm going as there is a point (10kw) with the POCO that comes with heavy regulation as you are no longer considered a residential self-provider... but a commercial producer. The planned system will be plenty for my needs.

[J.P.M.]

Spoke with the sole person responsible for interconnection with the POCO a few weeks back. Good to go there. Sent in my application already. Also already spoke with the county building inspector.. good to go there as well.

-Foo1bar-

As far as changing to a 200a panel... possibly. The electrician is coming back out Monday to take a peak at the panel in the shop.. will replace it if needed. I'll run it by him and see what he says. I already have the insulated tap fittings.. and I can't really go any larger then what I'm going as there is a point (10kw) with the POCO that comes with heavy regulation as you are no longer considered a residential self-provider... but a commercial producer. The planned system will be plenty for my needs.

Got it all in writing ? If not, verbal assurances aren't worth the paper they're written on. Just sayin'.

[Mr4btTahoe]

Got it all in writing ? If not, verbal assurances aren't worth the paper they're written on. Just sayin'.

Sorta I guess? The POCO requirements are in writing on the application itself which I'll be meeting all of those... and the inspector stated that it will be a basic electrical inspection which all of the electrical will be up to code. Neither need any sort of "plan approval" according to the written information I've received. I wont be buying anything, however, until the application is approved. I was told that it would take roughly 10 days for him to receive and review the application which will put me into April.

I THINK I have all my Is dotted and Ts crossed as much as I can... we'll just have to see how it plays out. Thanks for looking out.

[foo1bar]

As far as changing to a 200a panel... possibly. The electrician is coming back out Monday to take a peak at the panel in the shop.. will replace it if needed.

I thought you had said it was being replaced.
And if it's being replaced it's easy to replace it with a 200A bus-bar panel instead of a 100A busbar panel.

I already have the insulated tap fittings..

If you're putting in a new meter, new main panel and new subpanel, there's no need for tap fittings.
I think taps are viewed less favorably. I'd ask the electrician whether he thinks it's better to use tap fittings so the 100A breaker at the main panel feeds two subpanels or if it's better to have a breaker in the shop subpanel going to the solar.

I can't really go any larger then what I'm going as there is a point (10kw) with the POCO that comes with heavy regulation as you are no longer considered a residential self-provider...

Sure - but a 200A bus-bar makes it easy to go all the way to 10kW if you want.
And 200A bus-bar panels are very close in price to 100A ones.

Also I'd rather have a 200A busbar with 100A breaker feeding it than a 100A busbar- The 200A bus-bars would have more metal to them. Is it worth much really? No - but if you're replacing the panel anyhow I would expect the increase in cost to be pretty small.

[J.P.M.]

Sorta I guess? The POCO requirements are in writing on the application itself which I'll be meeting all of those... and the inspector stated that it will be a basic electrical inspection which all of the electrical will be up to code. Neither need any sort of "plan approval" according to the written information I've received. I wont be buying anything, however, until the application is approved. I was told that it would take roughly 10 days for him to receive and review the application which will put me into April.

I THINK I have all my Is dotted and Ts crossed as much as I can... we'll just have to see how it plays out. Thanks for looking out.

No thanks necessary. Just a suggestion that Murphy's law always governs. "If something can go wrong - it will".

[Mr4btTahoe]

I thought you had said it was being replaced.
And if it's being replaced it's easy to replace it with a 200A bus-bar panel instead of a 100A busbar panel.


If you're putting in a new meter, new main panel and new subpanel, there's no need for tap fittings.
I think taps are viewed less favorably. I'd ask the electrician whether he thinks it's better to use tap fittings so the 100A breaker at the main panel feeds two subpanels or if it's better to have a breaker in the shop subpanel going to the solar.


Sure - but a 200A bus-bar makes it easy to go all the way to 10kW if you want.
And 200A bus-bar panels are very close in price to 100A ones.

Also I'd rather have a 200A busbar with 100A breaker feeding it than a 100A busbar- The 200A bus-bars would have more metal to them. Is it worth much really? No - but if you're replacing the panel anyhow I would expect the increase in cost to be pretty small.

I did say that now that I look back.. but after talking to him, he said he'd just check out what I have and go from there. I agree that if the panel does end up needing replaced, it would be wise to go that route and more then likely will.

Thanks bud.

[Mr4btTahoe]

Got approval from the POCO on our application and components have been ordered!

[tyab]

While not directly stated already (unless I missed it on the quick scan of this thread), I would highly recommend spending $102 on the NEC code book. Make it your friend. Your going to be held to this standard in the inspection - sure would be a good idea to actually know exactly what is required. Note only that but you want a safe and long lasting installation - following this will help achieve that. I'm old school so I got the spiral bound book so I could highlight marker and sticky note tag those sections that related directly to stuff I was working on. Or get the PDF...

Best of luck! My #1 advice - take your time and don't cut corners. Oh and check out mcmaster.com for stainless hardware (which you will be using a lot of).

https://catalog.nfpa.org/NFPA-70-Nat...aspx?icid=D729 (get the version for the code year your state is on - ask the AHJ if there are any issues from a newer code that they require - ie, 690.47D)

[foo1bar]

While not directly stated already (unless I missed it on the quick scan of this thread), I would highly recommend spending $102 on the NEC code book.

Mostly I used their free online access, rather than buy the book.

I also used a PDF from archive.org (And before someone says "that's stealing" I'll point out that laws are not protected by copyright. And the NEC rules are laws when they are adapted by the government.)
If I were an electrician or a code inspector, I'd probably be willing to pay NFPA for a copy. It'd even be a legitimate business expense. But I'm just a DIY'er - so a free electronic copy is what I use.