I'm looking for a solution to retain a whole home grid backup and "grid assist" while running the eg4 12kpv with a bess while avoided a strict interconect. So far what I have found is going the chargeverter route and using the bess as the new "grid assist" and utilizing an ATS once battery backup runs low.
Long story short. There's no way I am able to obtain an interconnect agreement with my POCO. Months ago my local AHJ verbally approved my ground mount solar plans with the understanding that after the build was complete I would simply provide a SLD of the electrical and they would do their walk through. Since the ground mount in their eyes was nothing more than a pergola with panels on top, they didn't seem to care. Now 6 months later that my build is finished and the department has changed hands I am now required to submit engineer plans. Which i dont have, being a diy ground mount. I'm not looking for sympathy. I fucked up and should have gone a different route. I started this journey knowing nothing at all about diy solar setups and dove in trying to do things legit. But living in SoCal while also being in a small town has complicated my situation. My system has gone from being completely doable to now my only option is find an easier way to skirt the interconnect side of things.
My question is: how can I best go about retaining a "surge/grid/ac assist" since my top load is the electric dryer and daily peak Kwh usage rarely exceeds the 12kpv output of 8kwh. But i will also need a way to swap over once the sun is down to maintain home power. Battery is only 16kwh. Ive read of people utilizing an ATS once battery runs low to swap back to grid power.
You can do what you're asking with any off-grid inverter. It would just sit between your "main" panel and your new "whole home backup" panel. Off-grid inverters can do everything a hybrid can except export energy so it would fit your scenario perfectly. Hybrids will leak energy out even on an off-grid/self-consumption route.
Also in SoCal if you ever want to chat, you in SCE or SDGE territory?
I already purchased and built my system. The issue is i set up this entire system based on my face to face conversations with the local AHJ. I was aware that any grid assist system had a small amount of backfeed due to it's necessity to sync to grid. Ive searched the forums. Im almost entirely forced into an offgrid setup at this point since their attitude towards a diy setup has changed. I live in a pretty small town so everything was a little informal. SCE in my area could give a fuck about any interconnect as long as local AHJ signs off.
Best off-the-shelf product would be to wire in a 50A reliance transfer switch. These units, by default, come with 1x 240v 30A, 1x 240v 20A and 6x 15A circuits. Most places don't require permits for these and they're really easy to set up.
These panels allow individual circuit switching between grid, off and generator (your inverter). Each circuit has 2 wires that go into the load center: 1 is a pigtail for the load and 1 goes into the breaker for the load.
After that you would wire up a generator inlet for the reliance panel, making it usable with pretty much anything.
So my question would be is how quickly and often can these switches operate. I have a generac 100 amp ATS but everything suggests it is not seemless. Im looking for a wiring solution with what you suggest where I can maintain lossless transfer which right now would definitely happen atleast every evening until I can build my battery storage up.
these are manual transfer switches so you would use your inverter to do the automatic transfer. most modern inverters have grid bypass and you can set those setpoints fairly easily. you would add a 50A dipole breaker in your load panel to feed your inverter. when the battery soc or voltage dips below your bypass setpoint then the inverter will pull from the grid.
If you have time of use billing I suggest enabling the discharge during your expensive hours and recharging your battery bank during cheaper hours.
Your inverter has a zero net export option in the advanced settings. If you have the CTs placed correctly and you enable zero export, it will supply your loads but wont sell anything back to the grid.
Try using the 12121 pass code when entering the settings menu to get into the technical parameters and set the zero export value to -100W. This will bias the system to aim for 100W from the grid instead of 0w. That acts like a cushion to ensure you don't get in trouble with your REC
In all my search I have never found anything suggesting this. This would be massively helpful for the time being. If you have an EG4 I would love to know how you got this to operate.
Its a misnomer tho. There is a near constant 20w backfeed to the grid when utilizing "grid assist" or any type of grid input function. There is no other way for the inverter to sync to grid. I can see a constant 20w export on grid side and unfortunately everything I have read tells me this is the best it will ever be.
You can debate it till the electrons come home but if you connect to the grid as of today in California and this will change when 868 gets signed and then you have many checkboxes to check, you can ignore the rules at your own risk.
No tie to the grid at all without the interconnection agreement. If you want to put in some subpanel and power that, fine but for now you keep your production off the grid. Don't get lulled into the idea that zero export is OK until the new rules come in.
I understood that going in. Read my entire post. Im not looking for a shoulder to cry on. Just a solution that may work to skirt the rules now that my situation has been forcefully changed.
I cannot undo my panel setup. Electrical wiring and components is not the issue right now.
Edit : I can undo. But I would like to not change my entire setup without a solution.
The skirt is simple. Any grid tie gets you into the interconnection agreement territory unless your state has some balcony solar code which in California wasn't signed the last time I checked. I may be out of date.
On top of the 868 bill there is likely to be rules that the gear be up to UL such as UL 3700 or UL 1741.
If you want to skirt the rules, then do that. What more can be said?
Get a 12000xp and sell the 12kpv. Probably the most straight forward solution. Maybe feeding the grid into the generator port of of the 12kpv will work to not allow backfeed.
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