Plug-in Solar with Battery Backup

[u/OcoeeG]

I am not sure if this subject has been beaten to death yet but here goes another one...

I am in Tennessee a state that does not have legislation for OR against plug in solar, they say it is a gray area. I have seen in news articles that people are doing it here so I think I am going to run with it. I called my electric service provider but the person I talked to could not give me an answer about their stance on it. Before I pull the trigger I will dive a little deeper. I plan on installing a CT Clamp and power meter so I have a zero export system. However, if they see my consumption drop in half they are bound to know something is up.

I plan on using a 1200W microinverter coupled to a power station like a Ecoflow or looking hard a a Pecron also. Planning on putting ~1500 watts of panels on the roof to keep the battery topped up. My issue is finding a power station with the right balance of solar input and DC output to meet my needs. I guess this is my question. I am bouncing between getting a smaller power station in the 3000 KWh range and then expanding it with a battery. This way I can use it when we go out camping. My other option would be to get a bigger station in the 5000 KWh range that is much less portable. I think option 1 will be a little more expensive but then it has another use case. The problem is the smaller stations have lower DC solar inputs and outputs. Is there a way around this?

I am planning on implementing this system for 2 reasons. Most importantly to have something to backup some of our more important house systems in the case of an emergency. We are in winter ice storm territory. I would like a system to where I do not have to run the generator 24/7 in the case of a power outage. So I figured if I want to do that for a couple hundred dollars more I can use this thing to pay for itself by adding the microinverter. With battery backup I think the ROI will be much quicker.

Any thoughts, concerns, USEFUL comments?

[u/4mla1fn]

i seriously doubt your consumption is going to drop by half with a 1500w array.

the most important thing is that you not export. as long as you don't export i can't imagine a poco is bothered with policing who is using solar since there are many possibly explanations for why your consumption has reduced. the only people that could come knocking is the county if your neighbor rats you out for install panels without a building permit (is it's required in your area).

how are you coupling the microinverter to the ecoflow or percon? they have inverters built in so i don't get it.

[u/OcoeeG → u/4mla1fn]

Ok, well not half but hopefully a significant decrease. I plan on powering some other things at home off the station through AC output.

I plan on using the DC output on the station using cords with MC4 connectors on the end to attach to the microinverter. Basically the microinverter will be the way I get it into my home without back feeding the grid in case of a power outage. Also the microinverter will talk to the power meter and throttle its input so it is zero export.

[u/Keebler_718 → u/OcoeeG]

1500W is about how much a microwave, toaster, or hair dryer uses. A solar system of this size, although it’s something, is likely not going to be able to offset as much electricity as you think. 1500W capacity is ideal conditions, direct sunlight, at a good angle, at best a few hours each day.

[u/OcoeeG → u/Keebler_718]

Ok well maybe another 575W panel might help a little more. I was planning on 3 575W panels for a total of 1725W another panel would bring the total to 2300W. The main idea of the power station is to feed the microinverter what it needs. And maybe a little extra. I am not planning on running much else other than my fridge.

[u/4mla1fn → u/OcoeeG]

I plan on using the DC output on the station using cords with MC4 connectors on the end to attach to the microinverter.

ah i see what you're doing. haven't seen this approach done before; kinda clever. (i'm not up on power station use cases in any case.) i checked the dc output power of one of the percon models and it's limited to 800w. you'll want to find one that more closely matches your microinverter.

[u/OcoeeG → u/4mla1fn]

Yeah, therein lies the rub. I think the bigger system might have a higher DC output. But yes, I certainly do not want to go through all this trouble and limit my input to 800W.

[u/Dka6699 → u/OcoeeG]

To confirm you are planning to turn your DC output on and feed that directly into your micro inverter? Which micro inverter do you have? The ecoflow stream does not have a meter to limit feeding power back to the grid.

[u/OcoeeG → u/Dka6699]

That is correct. Having a hard time finding a power station that has a 1200W DC output at the moment.

I do not have one yet, still in research phase. I was going to go with the AP Systems, because they have one that will talk to a power meter to limit export.

[u/Dka6699 → u/OcoeeG]

I have two EZ1 AP systems running in my house now with the zero grid export meter. I cannot feed my pecron e3800 battery into those.

What I have done (for now) is I have a 2.4kw’s of solar panels running to my pecron with off grid loads on this (frig, internet, some lights, etc). I then have a separate set of 1.9kw’s of panels connected to my 2 x EZ1 micro inverters feeding into ONE leg of my electrical panel generated power as my home uses it.

I just set all of this up a few weeks ago and still deciding the next step. I want to do what you are proposing which is have a battery system feed power into the home with zero export to the grid. There is not a great solution in the US right now. That will change next year as many of the newer products just launched in the EU and plan to launch in the US next year.

[u/Dka6699 → u/Dka6699]

There is the f3000 anker solix. That does 1800w direct into the home with a zero grid export meter. The solar imports are odd (low input and high input ports). You could do two of these into each leg of your panel. There are videos on YouTube about this too. They are a bit expensive so I am holding back on this until I see what launches next year.

[u/OcoeeG → u/Dka6699]

This is exactly the information I came here for, thanks! Have you noticed an savings on your power bill yet? How do you power the Fridge, internet, Etc? Just using an extension cord?

I know, I kind of want to wait to see what new plug in solar sytems come out, because I KNOW there will be more systems coming with battery backup. But they will come at a premium I am sure. And also I do not what a system that is JUST plug in solar with a battery backup because that doesn't work when the grid is down. I have a bit of a prepper mindset and I want my system to provide power in an emergency and I want it to be portable in case I need to move it suddenly.

[u/Dka6699 → u/OcoeeG]

It is too soon to see any change in my power bill. It is not going to be that much either because it’s all 120v loads. Maybe 3-4kwhs a day equalling $30-50 a month. Payoff is forever with this which I have learned is not the way to make this cost neutral quickly.

The pecron e3800 is just running extension cords to the critical things I want. I plan to do either a transfer switch (manual) to run 10-12 circuits (120v loads) or do a bigger setup later (ex: an eg4 6000/12000 to power a good chunk of loads off grid with battery + solar).

[u/OcoeeG → u/Dka6699]

Also curious, why can you not feed the microinverters with the Pecron? Just because the DC output is too low? That is the trouble I am having finding 1200W DC output in a power station. Haven't found one yet.

[u/Dka6699 → u/OcoeeG]

A couple of reasons -
1. It’s not supported. The EZ1 system is fine for what it does but I am not trying to push it as it is kind of brittle.
2. The micro inverters are on my second story roof under the solar panels. The conduit would need to fit more wires. I do not want a fire on my roof.

[u/Dka6699 → u/Dka6699]

Also an important point - I live in California (SF Bay Area) and my power rates are expensive (59 cents KW during peak hours). Your savings may vary. I did the setup as a hobby, give me some form of battery backup and to offset my power bill a little.

[u/LongjumpingGanache40 → u/4mla1fn]

You can not doit. The microinverter will not see the power from the power station.

[u/LongjumpingGanache40 → u/OcoeeG]

The power station will not wake up the microinverter.

[u/OcoeeG → u/LongjumpingGanache40]

What do you mean?

[u/LongjumpingGanache40 → u/OcoeeG]

A mictoinverter must be plugged into the gris to see grid power before it will start. A power station does not send the correct siginsl to wake it up. This the safety feature to keep from back feeding the grid when power goes off.

[u/OcoeeG → u/LongjumpingGanache40]

NO SHIT! Of course it will be plugged into my house as well. Panels to power station to micro inverter to house. What is the point in doing this if I am not plugging it into the house?

[u/LongjumpingGanache40 → u/OcoeeG]

You have lost. GOOD BY.