what kind of permits would I need to add to enphase system?

[ryankshaw]

I have an existing enphase system on my roof. I net meter with the POCO 1:1. We use more power now than we used to. I'd like to maybe DIY add solar capacity to it.

The existing panels are above the living part of my roof. I was thinking of maybe trying to add panels myself on top of my garage's roof. Garage is connected to house. There is no ceiling in the garage so you can see the trusses and OSB (so you easily visually spot any leaks). The power company is Rocky Mountain Power. I believe the terms of my Net Metering Agreement are that I can add to the system up to 10kw of capacity and remain grandfathered into the 1:1 net metering rate. I've got 6.2kw (although I never generate that full amount), so that'd leave me at least 3.8kw.

existing system details:
6.2KW
21 Suniva 295 Watt all-black with Enphase S280 Inverters

What kind of red tape and permitting am I going to need? Do you have to have a building permit if you are installing solar panels on your own garage? Do I need a new agreement from the power company (or is the existing net metering agreement good as long as I stay under 10kw)?

I assume because the garage is connected to the house I have to do rapid shutdown and all those NEC requirements but that's why I was thinking I could maybe tie into the existing enphase rapid shutdown ability. I see in the enphase hub box on the side of the house next to the power meter there are 3 breakers for three PV circuits and only 2 are being used. so I was thinking I could maybe add the new array as that 3rd circuit.

or,
The option 2 that I've thought of is to just install an offgrid inverter like a MPP or a EG4 and put some loads from my garage (and maybe a couple new mini split heat pumps) behind it. Does that let me skip out on any of the red tape and permits (and extra $$$) I'd need to add to the grid interactive setup? Can you do that and add the panels under-the-radar if it's for an offgrid-only setup, or are they usually pretty hardcore about enforcing that too? I don't get why I can install my own shingles on my roof without permits but I couldn't install my own solar panels (with no net metering) on my roof.

My main goal is cost savings and getting back to the point to where I am fully offsetting my electricity consumption by the time they zero the credits in spring.

 

[Hedges]

Don't ask, don't tell.

With Enphase (assuming no battery), RSD comes for free.

I was going to say consider an AC coupled system for battery backup, but I don't know if Enphase S280 does Rule-21. Could work anyway on a hybrid that uses "generator" relay to shed.

Shingles don't burn houses down or electrocute people, but PV panels do.

 

[ryankshaw]

thanks for the reply!

With Enphase (assuming no battery), RSD comes for free.

yeah, that's why I was thinking: if I'm not going to run into problems from POCO for adding to an existing system, that would be the easiest way to add solar to my house. My next questions if I go down this route will be the technical stuff like "how do I get them talking to the rest of the enphase stuff?", but for now I am just trying to gauge how feasible from a red tape standpoint it is going to be.

...battery backup, but I don't know if Enphase S280 does Rule-21.

sorry, I'm still learning and don't know what that means. but fwiw, like I said, I am most interested in getting to full offset and don't really care about battery backup. so any battery capacity added would just be because if that's the most economical way to offset my usage.

 

[Hedges]

I don't think Enphase has to talk at all, unless you want to see reports. There may be an installer access to register them with a gateway or website.

Battery costs more, is either for backup when grid is down or to shift time of day you export or consume, due to time of use rates.

Older GT PV inverters shove 100% of what they can get from PV into the grid. California Rule 21 says as line frequency increases, inverter wattage output ramps down. This was for the grid, but also allows GT PV inverters to be managed by a grid-forming battery inverter. You can add such a battery inverter, one which supports "AC coupling", and it works with your existing inverters to make an off-grid system when grid is down.

As for permit requirements, varies by location and some neighbors might tattle. Once you've got a net metering agreement with utility, you can probably get away with quite a bit. If they wrote more code they could detect it, but not worth the effort. I would only use UL listed grid-tie equipment (UL-1741 etc.) because I trust it to shut off when grid is down.

 

[goldserve]

Beyond the net metering and permit issues if you choose to deal with, you should take the enphase university courses and learn how to put their system together. Not sure if your system has enphase combiner boxes and the wiring sizing to support more ac back feed to the panel. If your system was installed by a company, they probably would not give you installer access and would not want you to add to their system or that would create a warranty nightmare. Best is to learn the enphase system, use newer models and system components to create a separate parallel system.

 

[Siamac]

Contact your solar company. Sometimes they offer a lower price to add more panels to your existing system. More expensive than DIY still