Suggestions on choosing an inverter?

[J.P.M.]

If Washington state is on NEC 2020 you will have to pick a UL liste inverter if you want to pass building inspection, Any UL listed inverter will be able to isolate from the grid when the power goes out. In your case, since you want to use the grid but not sell back your criteria needs to include the ability to take grid input and Zero export. that narrows the selection especially if you want to comply with the building codes. You may need to use external CTs to control export depending on how it is wired. Many of the inverters on your list are not UL listed but some of them can be configured for zero export and use grid power to supplement solar or battery. It is my strongly held belief that you do not need to get agreement from your utility if you are not exporting but it is a gray area in the sense that the inverter is connected even though it may be set for zero export.. That said, you always need to comply with the building code.

Seems to me that the OP needs to get in touch with AHJs (note plural) in his jurisdiction and explain to them just what he wants to do.
Seems like we're all drifting around with a bunch of assumptions. Meanwhile, the OP seems quite uninformed about what's available and what rules need to be followed. No one on this forum from WA has offered any info specific to what's required, and others here - including me - are most likely ignorant of what the OP needs - partly because the communication has not been good and partly because the OP is a PV neophyte.
Just my opinion.

[azdave]

Seems I caused some confusion, LOL. I'll see if I can clear it up.

No. You did not clear that up. I did not find anything in your provided links that says they prohibit stand-alone solar generation behind the meter during an outage. I strongly feel you (or whoever explained it to you) have misunderstood the requirements, especially since they do allow stand-alone generators to be used in the exact same situation. If your assumption is correct, your PUD would be the only utility that I've ever heard of anywhere in the USA with such a requirement applied only to solar.

I did find this. "PUD 3 requires inverters to have an automatic voltage-sensing disconnect switch built into them to prevent backfeeding." It says it must prevent backfeeding which is 100% correct but it does not say it must prevent stand-alone solar generation. Solar generation during a grid outage does not mean you are backfeeding. I think your whole selection process is based upon an incorrect assumption and I agree with J.P.M. You first need 100% clarity of the requirements before you do any actual component selection. At least you are learning plenty along the way with all your research. No harm in that.

[rebelrider.mike]

Ok, I did some digging and here's what I found:

The PUD is not an AHJ and since I'm not back-feeding to the grid, their policies, whatever they are, don't matter. So we can drop that one.
Washington L&I is the only AHJ I have to worry about. They use the Washington Administrative Code (WAC) and do the permits and inspections. Since I'm not back-feeding to the grid, I don't need a specific UL standard certification. The inverter simply needs to be "listed". Under their definitions, that means any nationally recognized testing lab can give it a label and it's all good.

[Ampster]

......., that means any nationally recognized testing lab can give it a label and it's all good.

In my research I discovered that 15 states also use the CEC list as a reference, so if that is the case in WA it may be useful. At least your first order of rankon products on your list will be that criteria. Unfortunately for those who are not UL listed they often use confusing language to obscure that isse and it is alway nice to have an independent means to verify. Good luck with your install.

[rebelrider.mike]

I've been using the Emporia Vue to watch circuits I'd like to put on the solar sub panel. One is my dedicated freezer circuit.
Freezer.png
I've noticed that when the compressor isn't running it uses 13-15W all the time. I don't think it's supposed to do that. I'm also seeing that it uses 3.2kWh per day pretty consistently. That adds up to around 1,195kWh per year. There's some nice chest freezers at Home Depot that only use around 227kWh per year. That might save me a few dollars.

My old freezer was made in 1988. Still works great as far as keeping food frozen. It has a pretty high peak draw at about 14A. Runs on 2.5A. Looks like new ones peak at only 5A. Seems a shame to get rid of it while it works. But a new one would go a lot easier on an inverter.

[bcroe]

One is my dedicated freezer circuit. I've noticed that when the compressor isn't running it uses 13-15W all the time. I don't think it's supposed to do that. I'm also seeing that it uses 3.2kWh per day pretty consistently. That adds up to around 1,195kWh per year. There's some nice chest freezers at Home Depot that only use around 227kWh per year. That might save me a few dollars.

My old freezer was made in 1988. Still works great as far as keeping food frozen. It has a pretty high peak draw at about 14A. Runs on 2.5A. Looks like new ones peak at only 5A. Seems a shame to get rid of it while it works. But a new one would go a lot easier on an inverter.

It is a trade off you must consider. I found dozens and dozens of things
that used power when off, costing me thousands of KWh a year. It came
to a fair fraction of the bill in total.

The first step is identifying all these vampire loads, and inefficient operation.
A lot of stuff here was dumped or given away, to be replaced by Energy
Star rated stuff. Operating power was usually reduced to less than half,
and standby power well under a watt. Some things, like a GFI, door opener
radio, or TV remote turn on monitor, will never actually be zero.

Note, current matters, but only the part with zero power factor is billed.
Bruce Roe

[oregon_phil]

I will keep Solis in mind. I couldn't find any models that were split phase, but companies come out with new products all the time.

I remade my inverter selection table so it might be easier to read. As each unit hits a "deal breaker" the data stops, in order to reduce visual clutter. As I've learned more about inverters and how they work, I've been able to refine what characteristics I want in one.
InverterTable.png
The Deye is crammed full of features, and is probably worth the higher price. But I won't be using a lot of those extra features. Also, it's only available direct from China. So shipping will be horrendous. And if the unit I bought were to have a problem, I wouldn't be able to afford to send it back.

The EG4 is the one I'd get if I were to buy one today. I think its biggest flaw is the 115W of idle power usage. Not as high as some, but still kind of on the moderately high side.

I'm not going to rule out the other brands yet though. If any come out with an inverter I like better than the EG4, I'd definitely consider it.

I watched your Youtube videos listed in your profile. From your various projects, I get a sense that you like to tinker. For your latest Cargo Trailer project, you are building your own LiFePO4 battery bank. You are leaning towards an EG4 inverter with 48 volt battery. We're you thinking of building your own battery for this system because I can only find documentation for the EG4 inverter to use an EG4-LL battery but not anything else. The EG4-LL battery costs more than the inverter!

The EG4 6000EX-48HV as you noted has one MPPT. I noticed there are quite a few trees near or on your property (=shade). Therefore, you would probably need some sort of optimizer but TIGO doesn't list EG4 on the approved list. One solution is not to worry about it and just put rapid shutdown devices on your roof. I don't have an optimizer solution.

I have read through this thread and can't remember if you ran PVWatts for your home site. I know solar not top on your list, but if solar isn't really going to pan out, then it might not be worth pursuing. This could narrow your equipment set.

I also noticed your Mason County PUD3 power rates are very very low (~$0.09/kwh is that correct?). I'm sure others on this forum would like this rate too!

[Ampster]

........ You are leaning towards an EG4 inverter with 48 volt battery. We're you thinking of building your own battery for this system because I can only find documentation for the EG4 inverter to use an EG4-LL battery but not anything else. The EG4-LL battery costs more than the inverter!

The EG4 6000EX-48HV as you noted has one MPPT. I noticed there are quite a few trees near or on your property (=shade). Therefore, you would probably need some sort of optimizer but TIGO doesn't list EG4 on the approved list. One solution is not to worry about it and just put rapid shutdown devices on your roof. I don't have an optimizer solution.
.................

There are a lot of people on another forum who use the EG4 inverter with other batteries. What they may be saying is that closed loop communication may only be possible between EG4 inverters and EG4 batteries. I used an Outback Skybox without a closed communication loop between my BMS and the Skybox. I recently upgraded to a SolArk which can do closed loop communications and I prefer it becaus my Orion BMS has a more acurate SOC.

[oregon_phil]

Thanks for clarification. I'll have to read up on closed vs open loop communication. I don't have batteries, but there's always something to learn.

[rebelrider.mike]

I do love to tinker! Though as you can see here, I also like to research a lot before I start buying and building stuff. I hope you found my videos interesting.

The trailer project is still waiting for better weather. But I have built the battery already. It and a Wzrelb (Reliable) inverter run my mini fridge and air conditioner perfectly.

I plan to build my own house battery too. The pre-built ones look amazing, and some are even UL certified. As you saw, they're also very expensive. If you can afford them, they'd probably be a great way to go. I'd need 3 for my setup, and I can build my own for less than the cost of one. But I've been building batteries for a long time, and am willing to absorb the risk. Not sure it's worth learning all that's needed to do a battery safely if you want to build just one.

As Ampster said, the compatibility is about communication between the battery and the inverter. You don't necessarily need that communication for the battery to work. I've lost track of how many user manuals I've read but they pretty much all have a "user defined" option where you can put all the specs of your battery in manually. I plan to get a smart BMS and see if I can get it to communicate with the inverter using the pinouts to make my own cable. But if it doesn't work, its ok. The BMS will be loaded with safety features, and I'll also be using a bi-directional DC circuit breaker.

I do live near lots of trees. The deck where I want to build the pergola gets sun almost the entire day without shade. The carport has a tree that casts a shadow, and if I wanted to use that area, I'd probably take out that tree. Its growing right up against a fence, and I suspect that it is growing roots into my sewer line. Turns out the roof is just not a great place for panels, so I'll likely never put any on there.

I have been running my theoretical solar arrays through PVWatts. It turns out that around 4-5kW of solar modules will generate enough energy for what I'm hoping to do. I'm not looking to be independent of the grid, but I would like to power key circuits during a blackout with solar, and save a bit of money using the same solar during normal times.

We are pretty lucky here to have low power rates. Our base rate is $0.0771/kWh. Something like 80% of our electricity comes from hydro, and we also have wind, solar and nuclear. Only a little comes from fossil fuels. For me, solar is more about convenience and learning new skills than ROI. Though if I live long enough, this could be the first hobby of mine that actually pays for itself.

[oregon_phil]

I saw that Washington Administrative Code (WAC) follows NEC 2020 electrical requirements. I have read lots of discussions regarding NEC 2020 and Energy Storage Systems. You are more of a battery expert than I am and I am not an electrical engineer, but I am concerned that your DIY battery system will not meet your code requirements. I can only read so much discussion on NEC 2020 before my eyes water over.

[rebelrider.mike]

I do have the concern that the NEC is going to make solar/battery requirements so restrictive or expensive to comply with, that a lot of people won't be able to use solar. I plan to follow the code as closely as is feasible for me. I'm hoping it will lead to a passing inspection, but we'll see.

I actually have a copy of the NEC 2020, but it's slow reading and difficult to interpret. I'm still crawling through article 690 which has the info on solar stuff. I'm almost through it, though I wouldn't say that means I actually understand it. I really wish the code book came with a decoder ring, LOL.

Some good news is that WAC leaves some room for leniency as far as following the code. In my limited experience, inspectors respond well to an attitude of being willing to cooperate, and wanting to do things right. A lot depends on inspectors and their bosses. But leniency has its limits, too.

[SunEagle]

I do have the concern that the NEC is going to make solar/battery requirements so restrictive or expensive to comply with, that a lot of people won't be able to use solar. I plan to follow the code as closely as is feasible for me. I'm hoping it will lead to a passing inspection, but we'll see.

I actually have a copy of the NEC 2020, but it's slow reading and difficult to interpret. I'm still crawling through article 690 which has the info on solar stuff. I'm almost through it, though I wouldn't say that means I actually understand it. I really wish the code book came with a decoder ring, LOL.

Some good news is that WAC leaves some room for leniency as far as following the code. In my limited experience, inspectors respond well to an attitude of being willing to cooperate, and wanting to do things right. A lot depends on inspectors and their bosses. But leniency has its limits, too.

Being an EE for more then 45 years I use to have every copy of the NEC from 1975 and as far as I am concerned it will always require an attorney to decipher. What I can say is that even though you might follow the latest NEC it still falls to the AHJ who will decide what is allowed and what is not.

[rebelrider.mike]

This right here, LOL:

[Ampster]

I do have the concern that the NEC is going to make solar/battery requirements so restrictive or expensive to comply with, that a lot of people won't be able to use solar. .....

NEC 2020 has already done that with the requirement for UL listed batteries. My jurisdiction has not approved that version yet so SunEagle is correct, best to check with your AHJ.