Upgrading SolarEdge system

[mjsfbay]

I'm in California and looking to upgrade my solar array prior to NEM3 going into effect (4/14/2023).
My system is 3.71 kWp and covers approx. 50% of my energy needs - leaving me with a $400+ true-up bill at the end of the year.

The current system comprises:
Inverter:
1 x SolarEdge SE5000H-US
https://www.solaredge.com/sites/default/files/se-hd-wave-single-phase-inverter-datasheet-na.pdf

Power Optimizer:
13 x SolarEdge P320
https://knowledge-center.solaredge....rame-mounted-power-optimizer-datasheet-na.pdf

Solar Panels:
1 string of 13 panels - Hanwha Q-Cells Q.PLUS BFR-G4.1 285 (285W) Solar Panel

Q-Cells Q.PLUS BFR-G4.1 285 (285W) Solar Panel

I discovered that I can upgrade my inverter at any point while remaining NEM2 compliant, so there's no particular rush at the moment. However, I can only increase the size of my array by 10% or 1 kWh (whichever is met first) without triggering NEM3 billing - Unless I get a plan approved before 4/14/2023.

I've got the following questions that all the googling in the world can't seem to provide an answer:
- Does this inverter REQUIRE P320 optimizers for each panel?
- Can I add a second string of higher-wattage PV panels to this inverter without downgrading to the lowest string wattage?
- Is Sol-Ark my best option for AC coupling to this inverter for the purpose of battery storage, or is there another better option?
- If AC coupling is the best option, would it make more sense to add a second string to that inverter vs. my current grid-tied inverter?
- If planning to AC couple a hybrid inverter with a separate array - wouldn't this technically qualify as an off-grid system and, generally, not fall under municipal code until/unless it is AC coupled?

It seems that I may be missing some basic concepts, so I realize these may be silly questions to some. Feel free to point me in the right direction if you know of a resource that helped you get the basics down.

Thanks for your help!

 

[zanydroid]

There are some SolarEdge fanboys here and on Reddit, that might be a good way to get the answers. Same with Enphase, etc.

I'm not an expert on SolarEdge but I think they really really want you to buy their fancy optimizers.

My understanding is that each string is paralleled onto an internal DC bus, and the output wattage is determined in large part by the inverter output sitting on the DC bus. So the strings should share that budget and if one is lower the other can be higher. Setting up separate MPPTs for different roof orientations is a pretty common way to overpanel, each roof plane will peak in production at different time.

Worst case, if you can't figure this out, just get the cheapest grid tied inverter so you can get new panels up.

- Is Sol-Ark my best option for AC coupling to this inverter for the purpose of battery storage, or is there another better option?

I think you should wait on AC coupling for battery, things will get way cheaper/more choices in the next few years.

- If planning to AC couple a hybrid inverter with a separate array - wouldn't this technically qualify as an off-grid system and, generally, not fall under municipal code until/unless it is AC coupled?

All electrical stuff needs to be done in a way that satisfies your AHJ.

The ambiguous part is whether it affects NEM. If you add off-grid of any sort, you'll increase your NEM exports / change your export power vs time profile, which is something the utility cares about and vetted during your interconnection process. It's mathematically & social impact equivalent to adding more PV panels, which you are not allowed to do over 10% without being forced onto NEM3.

I don't know if this has any case law precedent or official PUC ruling.

 

[mjsfbay]

Insightful! I appreciate your feedback, Zanydroid. A lot for me to think about.

 

[400bird]

I'm in California and looking to upgrade my solar array prior to NEM3 going into effect (4/14/2023).
My system is 3.71 kWp and covers approx. 50% of my energy needs - leaving me with a $400+ true-up bill at the end of the year.

The current system comprises:
Inverter:
1 x SolarEdge SE5000H-US
https://www.solaredge.com/sites/default/files/se-hd-wave-single-phase-inverter-datasheet-na.pdf

Power Optimizer:
13 x SolarEdge P320
https://knowledge-center.solaredge....rame-mounted-power-optimizer-datasheet-na.pdf

Solar Panels:
1 string of 13 panels - Hanwha Q-Cells Q.PLUS BFR-G4.1 285 (285W) Solar Panel

Q-Cells Q.PLUS BFR-G4.1 285 (285W) Solar Panel

I discovered that I can upgrade my inverter at any point while remaining NEM2 compliant, so there's no particular rush at the moment. However, I can only increase the size of my array by 10% or 1 kWh (whichever is met first) without triggering NEM3 billing - Unless I get a plan approved before 4/14/2023.

I've got the following questions that all the googling in the world can't seem to provide an answer:
- Does this inverter REQUIRE P320 optimizers for each panel?

Yes, Solar Edge requires optimizer for each panel, but possibly not the P320 specifically. If you are mounting on a roof, your city likely requires them (specifically, the rapid shut down that they provide) too.

- Can I add a second string of higher-wattage PV panels to this inverter without downgrading to the lowest string wattage?

The optimizers can handle pretty drastic differences in strings. I had an 8s and 12s string in parallel.

- Is Sol-Ark my best option for AC coupling to this inverter for the purpose of battery storage, or is there another better option?

Sol-Arc is on option. Best is an option. I'd want something with a transformer (low frequency inverter) with better motor (air conditioning) starting ability.

- If AC coupling is the best option, would it make more sense to add a second string to that inverter vs. my current grid-tied inverter?

Depends on the goal. You'd get there both ways. Considering the quickly approaching deadline, I'd go with the quickest option (adding more panels to the Solar Edge)

- If planning to AC couple a hybrid inverter with a separate array - wouldn't this technically qualify as an off-grid system and, generally, not fall under municipal code until/unless it is AC coupled?

Probably not, they want the house to be safe and will want permits and inspections. AC coupling is possible in a true off grid set up, so I don't think that's a demarcation between needing a permit or not. If you are working with to stay on NEM 2, the power company is going to require permits and inspections.

It seems that I may be missing some basic concepts, so I realize these may be silly questions to some. Feel free to point me in the right direction if you know of a resource that helped you get the basics down.

Thanks for your help!

 

[mjsfbay]

Great to know, 400bird. I just got off the phone with SolarEdge, and confirmed optimizers are required on each panel. Seems like a money grab, but good to know there are some operative reasons for them aside from panel-level monitoring. Thanks for your insight.

Also, sadly, I spoke with my city permitting office and even despite me being a licensed contractor, I cannot install my own system without being a licensed electrician. So I reached back out to my original installer, Freedom Forever. They quoted me $14.8k ($11.4k if cash) for a 3.2 kWh addition, using my current inverter. Seems like a horrible ROI.

 

[zanydroid]

Wow, that sucks. I have heard similar stuff from some California cities though.

Can you group this with another project so that you can be the GC on the permit then use a licensed electrician for some basic stuff like swapping in a combiner panel?

For my city they don’t examine the subcontracting structure. Then again they let me do whatever I want electrically and solar panel speaking.

 

[mjsfbay]

Yeah, my municipality has a reputation to uphold. I might be able to subcontract out the work but then may as well hire out the whole project. So, back to square one..... Solar installation companies gouging customers to capitalize on the NEM2 ---> NEM3 deadline.

Worst-case scenario, I keep my array as is. I suppose even with a 3.7kW system AC-coupled battery storage will give me a decent ROI once the cost of components drops some.

 

[400bird]

Wow, I pulled owner builder permits for my installation. I even replaced the service enterance and main breaker panel.

 

[zanydroid]

Yeah, my municipality has a reputation to uphold

LOL, is this an inside joke of some kind?

You can run the numbers on upgrade to ESS assuming future non-insane price of an ESS. There are a few scenarios, the more extreme of which is to go to (1) NEM3 at PV size = 150% of annual demand, (2) self-consume at unlimited with no export privileges, and (3) intermediate one being taking advantage of the storage upgrade provision in NEM2 (I don't know the details).

 

[zanydroid]

I guess the other option is to dig around to see if a grandfathered NEM2 application under your name is transferrable to an installer. I'm sure there will be some hungry ones under some scenarios for how the solar install industry will go in the next 3 years.

 

[zanydroid]

Do they have a reason / local statute they can cite for the requirement for licensed electrician or solar installer?

I can kind of see the point more if it's a DC system.

But for microinverters, I'm sure 50% of DIYers will do it more carefully than the crew that installed on my house...

 

[mjsfbay]

LOL, is this an inside joke of some kind?

You can run the numbers on upgrade to ESS assuming future non-insane price of an ESS. There are a few scenarios, the more extreme of which is to go to (1) NEM3 at PV size = 150% of annual demand, (2) self-consume at unlimited with no export privileges, and (3) intermediate one being taking advantage of the storage upgrade provision in NEM2 (I don't know the details).

Not a joke... just sarcasm.

Option 3 seems to be my best bet if I want to keep throwing money at the issue.

 

[mjsfbay]

I guess the other option is to dig around to see if a grandfathered NEM2 application under your name is transferrable to an installer. I'm sure there will be some hungry ones under some scenarios for how the solar install industry will go in the next 3 years.

That's an option for sure. I'm in contact with Renvu / illumine-i regarding plans. Don't know how much this option will cost me yet though.

 

[mjsfbay]

Do they have a reason / local statute they can cite for the requirement for licensed electrician or solar installer?

I can kind of see the point more if it's a DC system.

But for microinverters, I'm sure 50% of DIYers will do it more carefully than the crew that installed on my house...

Anecdote:
I once went to the building department to ask a question. They told me I'd need a permit and a licensed electrician to change out a single outlet.

 

[darkskies]

So they don't allow homeowner to do any electrical work, if if you follow code? Here in NH, in my town, as long as I follow code and have a permit and inspection, I can do electrical work.

 

[400bird]

I thought California didn't allow cities to block owner builder permits. Maybe you go back in and ask for owner builder paperwork.

 

[mjsfbay]

You all may be right. It's easy enough to get an owner-builder form - they're available online. However, this is what the people at the front desk told me. I'm just leery of going against the grain when I'll need permits approved and inspections passed. If I was a pro or, at least, had significant experience with building out these systems, I'd be willing to push harder.

Is there a source you all recommend, other than YouTube and chat boards, for learning the fundamentals of building out these projects?

 

[goldserve]

What’s your county? I’m also in CA and you can pull owner permits. I plan on upgrading my service entrance to 200A and main panel. This I have to coordinate with PGE for disconnect and reconnect.

 

[mjsfbay]

San Mateo Co.

 

[goldserve]

Me too but my city is Belmont.