Newbie needs help. EG4pkv for both critical and noncritical loads on battery power...is it possible?

I am a totally newbie to all of this, need some guidance on if my idea for my house is possible.

TL;DR - Looking to see if there is a way to use a EG4 18kpv to power my whole house for small outages, use battery for the whole house during peak TOU prices, but power only critical circuits for long outages (automatic cut-over of some sort)

Background:
I live in S. FL (HOT!), 2 story house w/ a 3.5 & 4 ton air conditioners, pool & hot tub, and all electric appliances (no gas). I use Emporia today to track my usage, I use between 40-120 kWh a day depending on time of year and air usage. My peak usage appears to be around 13kW, but normal load is much lower than that.

I am looking to build a system with 3 goals

1 - Keep everything (or virtually everything) on during small power outages. We get brownouts and 1-3 min power outages frequently. Would like to keep the house running (minus the pool, no need to keep that on in a grid outage)

2 - Hurricane prep. In case we have a multi day to weeks long outage, I want enough power to run critical loads, possibly add a propane generator to the mix for really long extended outages.

3 - Cost savings. As of now I am not planning on doing solar (not ready for that level of expense, roof is already 15 years old, and not sure if we will live in the house long enough to recoup the costs. So really my only option for cost savings is to use TOU rates, charge up the batteries when it's cheap, run primarily on batteries when it's expensive. Looking at my energy usage over the past year, my max consumption during the peak times would be around 38 kWh in the heat of summer, closer to 25kWh rest of year.

Since we are unsure how much longer we will live in this house, I was originally looking at portable solutions like the EcoFlow DPU, but the size the system for what I'm looking for would be too expensive and their smart panel won't power my whole house. So now I'm looking at the EG4 18kpv and 2-3 of their wall mount indoor batteries. 2 batteries will only give me 28.6kwh but is half the price of my original EcoFlow plan. 3 batteries (43kwh) is more than enough but may be more than I want to spend.

What I'm trying to figure out is how to accomplish all 3 goals. To use battery as the exclusive/primary power source during peak times, every circuit needs to be on the 18kpv load (I know only 12kw can come from the batteries and then the grid supplies the rest). But when the power goes down for longer than a few minutes, I want the system to automatically shed specific loads but give me the option of manually turning them back on individually when needed. How do I do this? Can I have 2 Subpanels, one for critical loads that is always powered, and a 2nd that is non critical loads that can auto shut off when the grid goes down? or perhaps some sort of automatic transfer switch to do this? or Smart breakers? but how would the breakers know that the grid is down...

Sorry for the long post. Thanks for any help you can give.

I don't know when Sol-Ark is ever going to get another product to market, but this would do what you're asking.

gwrapps said:

I am looking to build a system with 3 goals

1 - Keep everything (or virtually everything) on during small power outages. We get brownouts and 1-3 min power outages frequently. Would like to keep the house running (minus the pool, no need to keep that on in a grid outage)

2 - Hurricane prep. In case we have a multi day to weeks long outage, I want enough power to run critical loads, possibly add a propane generator to the mix for really long extended outages.

3 - Cost savings. As of now I am not planning on doing solar (not ready for that level of expense, roof is already 15 years old, and not sure if we will live in the house long enough to recoup the costs. So really my only option for cost savings is to use TOU rates, charge up the batteries when it's cheap, run primarily on batteries when it's expensive. Looking at my energy usage over the past year, my max consumption during the peak times would be around 38 kWh in the heat of summer, closer to 25kWh rest of year.

Since we are unsure how much longer we will live in this house, I was originally looking at portable solutions like the EcoFlow DPU, but the size the system for what I'm looking for would be too expensive and their smart panel won't power my whole house. So now I'm looking at the EG4 18kpv and 2-3 of their wall mount indoor batteries. 2 batteries will only give me 28.6kwh but is half the price of my original EcoFlow plan. 3 batteries (43kwh) is more than enough but may be more than I want to spend.

Click to expand...

Can't backup the whole house with a "portable" system.

Something like the EG4 6000xp can backup a critical loads panel (#2 hurricane prep).

For #1 (whole house for a short period of time), you are looking at an EG4 18kPV or Sol-Ark 15k, both with large pass through capability, or EG4 12k, Sol-Ark 12k, Midnight Solar 10k, or Growatt 10k with less passthrough capability.

The inverters for #1 can be used for #2 by: 1) manually turning off large loads when the Hurricane hits; or 2) Use the Smartload connection that turns off when the Battery SOC is below a certain threshold. If you set the threshold to 95%, then all loads stay on during an initial outage, and during a longer outage, the large loads are turned off to save battery for the critical loads.

As I'm planning a future whole house battery install, my plan is to NOT bother with a critical loads panel. All of my large loads are easily manually controlled. and I don't have large parasitic draws I can't remove.
And one runs into issue (sometimes) of outlets you'd want off, and others definitely on, on the same circuit. Are you ready to do some re-wiring? I get why that might be appropriate in some circumstances... but in general, why bother?
Get something like Emporia or similar so you can see what is using the kWh, and go from there. Large load systems like A/C, EV charger, electric dryer, etc are non-issues to simply not use if trying to preserve battery. A reason that comes to mind to go to complexity of critical loads panel is if there are others in the house who will ignore electricity use restrictions and you want to make sure they can't screw things up, in which case, you have my sympathy.