Suggestions on choosing an inverter?

[sdold]

Hmmm, Ive never heard of em and Im a solar guy

They look like cheap Chinese products market by 20-somethings unfamiliar with the technology. The website is full of "information" like this, in the battery-to-AC inverter section:

"Will a 12 volt inverter work with a 24 volt solar panel? No, a 12V inverter will not be compatible with a 24V solar panel. You will need a 24V inverter to work with a 24V solar panel. It is important to match the voltage requirements of your solar panel and inverter to ensure proper functioning of your system."

The product manuals are pretty amusing. Here's the extent of their advice on the cabling between the battery and 2000W inverter:

"4. The battery end needs to be installed with insurance, which is selected according to
the inverter input rated current of 2-2.5 times"

No mention of wire sizes or fuses. The inverter "rated input current" is not mentioned in the manual, but we can guess what it would be at 2000 watts! I do like the part about insurance though.

Edit: I just tried to call them, well within their business hours, and got "You have reached a customer whose voice mailbox has not been set up yet"
I'd steer clear of these guys and get something from an established company like Victron.

[rebelrider.mike]

Well, it's been about a year since I posted any updates, so I guess one might be due.

I still haven't made a final decision on the inverter. But right now I'm strongly considering the EG4 18KPV. In fact, I've become something of an EG4 fanboy, as I also plan to buy one of their 48V wall-mount batteries, as well as their Chargeverter.

I spent most of 2023 studying the NEC 2020 to get a really good handle on how I need to do things in order to pass an inspection. I've also looked much deeper into local laws and what my options are as far as how to design and operate my system. Also, my priorities have changed a little as I've learned more about all this.

Between the Emporia Vue, and the PUD's digital energy meter, I have a year's worth of energy usage data for both the whole house and specific circuits that I plan to power with solar.

So here's my new list of requirements for the inverter:

• Split phase 240V 60Hz: At this time, so many companies have one of these available, there's really no excuse for companies that don't.
• NEC 2023 compliant: This means more than just being listed by a safety lab.
• Outdoor rated: Turns out I don't have room inside for the inverter, so it will have to go outside. Also, this solves a bunch of NEC compliance headaches instantly.
• Hybrid: Able to accept power from both solar and battery, as well as other AC and DC sources.
• Multimode: Able to function as a grid-interactive and standalone inverter.
• Inverter efficiency: DC to AC conversion must be at least 90% efficient.
• THD: Total harmonic distortion must be published, and must be 3% or less.
• Load sharing: The inverter must be able to draw on multiple sources of power simultaneously to meet load requirements.
• Grid passthrough: The inverter must be able to send at least 60A from the grid to the load center.
• Idle power: The inverter must consume less than 100W while at idle.
• Price: Approximately $5k or less.
• Availability: Must be available for purchase in the US.

The plan still remains to install things in stages. In fact, stage 1 is nearly finished. I have the new sub panel installed as well as the transfer switch, breaker, and inlet for a generator. I still have to clear a spot for the generator and make some kind of weather protection for it. So I haven't bought it yet. I've also not yet moved the desired circuits over to the new panel. Except for the washing machine. I've got some construction work to do elsewhere in the basement before I can start moving circuits over.

Stage 2 is still the inverter and battery, along with a bypass switch and shutoff so I can route electricity from the service panel to the sub panel if the inverter were to have some kind of issue. Once I get to this point, I'm strongly considering re-routing the generator circuit so it charges the battery directly. So I may also install an EG4 Chargeverter.

Stage 3 is adding the solar panels. This one is still up in the air (no pun intended) as I've found out the local building codes require an engineered mounting system for the panels. Which means I have to hire an engineer to design it. I don't know yet how much that's going to hurt financially.

I've given up on trying to make this project have financial sense. All the legal requirements have grown my ROI to at least 26 years. I wasn't originally planning to sell power back to the PUD, but it looks like I'm going to have to in order to limit the monetary damage.

Anyway, I've drawn up some scale picture of what the system would look like:
Slide3.JPGSlide4.JPG

EG4 just came out with an indoor version of their wall mounted battery. I haven't updated these pictures with that version yet. It's slightly narrower, which will be nice since my space is still cramped even with the inverter going outside.

[solar pete]

I recommend considering the Bougerv series for solar inverters. They're known for their reliability, efficiency, and user-friendly interface, making them a popular choice among solar enthusiasts.

Hmmm, Ive never heard of em and Im a solar guy

[rebelrider.mike]

I've not heard of Bougerv inverters. I'll look at them, thanks.

[Btyreprich]

I recommend considering the Bougerv series for solar inverters. They're known for their reliability, efficiency, and user-friendly interface, making them a popular choice among solar enthusiasts.

Moderator edit: I removed his first ad link and asked him not to post such links, he came back and edited out my comment and re-inserted the link, so he is now banned. Another reason to avoid this brand in my opinion. Thank you to the member who flagged the post.

[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.

[rebelrider.mike]

This right here, LOL:

[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]

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.

[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 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]

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.

[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]

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!

[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