Connecting new system to existing Enphase setup

[Arob]

I'm considering installing a new system on my garage and tying into my existing Enphase system. I won't do a critical loads subpanel, the Span Panel already serves that function and is technically a subpanel. I don't plan to sell back to grid, but I need a grid-tie system for AC coupling (I think). I am no expert here so go easy on me.

Current System
Enphase system with IQ7x inverters, 2 x Enphase 5P's, 13 Panasonic Modules and Span Smart Panel with Remote Meter Kit. System is solid, works fine. The Span is very cool.




Proposed New System
I have room on my garage for 6 modules. I can wire them back to the basement in my house where I would install battery and inverter. I'm not married to any particular brands of gear. I have the EG4 battery and Sol-Ark 5K so far because they seem to be capable.



Where to Connect New System ?
The is where I'm not clear and if this is possible at all. Would using the output of a grid-tie inverter and making any of these connections work? I contacted Span and they said connecting to the panel is fine as long as your using a grid-tie certified inverter. They couldn't speak to using two systems. I contact Sol-Ark and they weren't much help answering my questions. I haven't reached out to Enphase yet. The 3 connection possibilities I'm seeing are:

1. Can I connect to the Enphase controller? This is where AC from my existing panel comes in, after going thru the combiner.
2. Can I connect the AC out of the inverter to the combiner? Can the AC phase of the inverter work with Enphase inverter output?
3. Will connecting the AC out of the inverter work connecting to Span panel? What would happen in a grid down situation.

 

[MaikaiLifeDIY]

I believe you're on the right track with your inquiry, although I can't provide a definitive answer. However, I can share my experience with a similar setup involving my Enphase system and a Sol-Ark 15K.

In my case, I didn't have Enphase batteries, and my system was solely grid-connected.

What I did was designate the Sol-Ark as the central control unit. The grid power entered through the Sol-Ark to the house, although it's worth noting that my setup involved a 15K unit rated for 200 AMPs passthrough, which is higher than the 5K 63A Sol-Ark.

When the grid was operational, power from the Enphase system would pass through the Sol-Ark, which determined whether the energy was stored in batteries or sent back to the grid. During grid outages, the Sol-Ark essentially mimicked the role of the utility, keeping the Enphase system online. Once the batteries reached around 80% capacity, the Sol-Ark increased the AC frequency to approximately 62Hz, triggering the Enphase system to shut down to prevent overloading.

In your situation, it seems that your Enphase system manages power flow in and out of the home. Similar to my setup, when there's no available storage for generated energy (either in batteries or the grid), a controlling mechanism is necessary.

Backfeeding the combiner or panel may pose challenges because the Enphase system might not recognize the source of internal energy and could potentially encounter issues with shutting it down. Integrating Enphase to power down the Sol-Ark without extensive integration work seems unlikely. If the Enphase system needs to shut down inverters, it can signal them directly, if the source of energy isn't controllable, it could lead to complications.

Exploring this further will require thorough research and experimentation on your end. Ultimately, you won't completely know if it'll work until you've purchased and connected the equipment. I recommend fully exploring options to expand your existing Enphase system before delving deeper into this setup.

 

[DIYrich]

Option 1: add more enphase micros and battery.
Option 2: enphase output to sol-ark grid input. Sol-ark load output to Span. Set solark to zero export. The SA will run as a silent partner.

The problem is batteries on both inverters. They both can't be intelligent. Since span works with Enphase, that is the one to keep intelligent. 18kpv will also work. You want something in-between that can pass through the amps you need.

 

[wheisenburg]

Unfortunately, you are into the territory of trying to combine equipment that was never intended to work together. My first question would be what are your expectations? What are you trying to accomplish?

More solar production? Your IQ Combiner box isn't near maxed out. You should be able to easily run 11,000 watts through this box. Just make sure the wiring between the System controller and the combiner is adequate. If the combiner has room for 4 circuit breakers you could go up to 15,000 watts. The only issue is that the installer likely only installed wire adequate to carry the actual load you have now, and not the maximum the combiner is capable of. This is easy to solve with 6 micro and 6 panels. Budget is about $2,000 plus racking and installation.

Now unless you physically separate these new panels into a completely isolated and parallel off grid system, this will constitute a modification of you grid tied system and you will need a new PTO from your utility. So if there is any way for your new panels to feed power into your span, you will need a new PTO.

More battery storage that you can use when the grid is down? This one is going to be difficult. Your best bet here would be to setup the inverter and battery as if it were an off grid system. Use a charverter to charge the battery. Then use the generator input to the Enphase system. Enphase limits what generators you are allowed to connect to their equipment. You won't get an installer to do this for you. You could go through the classes and become a certified installer and then try lying to then about what you are doing so you can get the generator port commissioned. Enphase makes some great equipment, but they are not DIY friendly. Especially when it comes to battery systems.

More inverter capacity when off grid? Get this inverter to run in parallel seamlessly with the Enphase equipment when off grid. If you have to ask, you don't know how to do this, and no one will help you, and it's probably not possible.

You can message me if you want.

 

[wheisenburg]

What I did was designate the Sol-Ark as the central control unit. The grid power entered through the Sol-Ark to the house, although it's worth noting that my setup involved a 15K unit rated for 200 AMPs passthrough, which is higher than the 5K 63A Sol-Ark.

This is important. If you have grid tied PV micros only, it is possible to put the sol arc in front of those micros. The Sol Arc has the smarts to manage the micros and control their output.

When you already have the Enphase System Controller and batteries, it becomes very dicey trying to shoe horn another Hybrid inverter into the system.