Suggestions on choosing an inverter?

[Ampster]

I thijnk rebelrider.mike said he is not looking to feed power to the grid but would like to use the grid as a backup. He may wish to claify if an interconnection is needed. Howecer, for other readers who are anticipating an interconnection in California, they should have as one of their first rank order criteria the fact that a particular inverter be listed on the CEC site.

The above list would be useless for those readers who want an interconnection since the CEC status is not shown. I do know for a fact that the DEYE is not listed and am pretty sure some of the others are not listed on the CEC site as well. I think it may be implicit in any NEM agreement that the inverter be listed on the CEC site. The CEC site says the list is for any interconnection requests in California without referencing a NEM version. Also the online application for PG&E and SCE have a pulldown menu item that can pull the values for listed inverters into the application form. I do not have any experience with SDG&E.

[J.P.M.]

I guess it depends on how you define "sold into CA"? Do you mean, on the CEC list?
Very ffew of the Chinese inverters listed are on the CEC list but you can get them shipped to California from China. I am not taking issue with your statement, just seeking clafification.

Well, I use "sold into" to mean used as part of a residential electrical generation system in CA.
If the OP is not in CA or is in CA but not required to be covered by an interconnection agreement, then my statement is possibly incorrect by virtue of some incorrect assumptions.

However, if the OP is in CA and he's stated he will want the ability to feed power to the grid, that will mean an interconnection agreement.
If he's in CA I'd think that would mean NEM 3.0.
Now, NEM 2.0 requires a minimum 10 year inverter warranty.
In my snooping around, I've not been able to locate the specifics of inverter warranty requirements under CA NEM 3.0. However, all the documentation and info I've been able to locate and read that cover changes from NEM 2.0 to NEM 3.0 I've not seen any mention of any changes to equipment warranty requirements.

So, I'm of the opinion that if the OP's system will be in CA and if he wants to sell power back to the grid as he's stated, and if he's either a current or soon to be customer of some CA POCO that requires an NEM agreement, he'll need an inverter or inverters that carry a 10 year or greater warranty in addition to meeting all other requirements imposed my applicable codes in force in the jurisdiction where the equipment is located.

[Ampster]

Last time I checked, any inverter sold into CA needed a 10 year warranty.

I guess it depends on how you define "sold into CA"? Do you mean, on the CEC list?
Very few of the Chinese inverters listed on the above list are on the CEC list but you can get them shipped to California from China. I am not taking issue with your statement, just seeking clafification for the benefit of other readers.

[rebelrider.mike]

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.

[J.P.M.]

Solis also provides a 10-year warranty and is a large enough company to be around 10 years from now. Many inverters sell with a 5-year warranty and not something I would consider when others at the same price have a 10-year warranty.

Last time I checked, any inverter sold into CA needed a 10 year warranty.

[Calsun]

I bought the Solis as it had the latest and greatest engineering of the inverters I could research. I like that they have an external port where you can attach an adapter and use a USB drive to apply firmware updates yourself. The same port works with a Wifi adapter so you can access it over the internet or with a smartphone to monitor activity. The Solis customer support provided by phone is also very good and that is as important as any other aspect of a device.

I bought a 5G model that can charge a battery backup system in the future. At current battery prices it is not a good choice in my situation but as battery prices decrease it may be a good move in the future.

Solis also provides a 10-year warranty and is a large enough company to be around 10 years from now. Many inverters sell with a 5-year warranty and not something I would consider when others at the same price have a 10-year warranty.

[nerdralph]

I don't know if this would be interesting or useful to folks, but its easy to share, so...

InverterSpecsA.png
These are the first of the specs I've compiled for each inverter I've researched. The cells I marked red are the deal-breakers for me. But they may not matter to others.

Anyway, 4 of these didn't get eliminated, and I'm looking into a few more specs to see if I can choose one over the others.
InverterSpecsB.png
As you can see, this list is still incomplete, and I've got to go back and take a closer look. I did my best to find at least 1 product from each popular brand that I'm aware of.

I don't believe the claimed 97% efficiency for the Deye 6K inverter. Get an inverter with a CEC efficiency rating, so you can verify it online.

https://www.energy.ca.gov/programs-and-topics/programs/solar-equipment-lists

[nerdralph]

I've been pleased with the quality and support for Solis string inverters. They make a hybrid too (which I've never bought).

https://www.ginlong.com/energy_storage_inverters8/3,8_11,4k_s6_h_us.html

The Growatt 6000TL-XH-US may be worth looking at as well. I've installed one without batteries.

[Calsun]

My Generac standby generator runs off natural gas so unlimited fuel supply and it weighs more than 400 pounds and is screwed to a concrete slab. It is also behind a locked gate with a 2x2 inch metal frame. Pretty near impossible to steal by anyone.

The cost was the same as for a comparable output Tesla powerwall and the powerwall would provide power for at most two days and so not a good solution as we have power out for longer periods of time. Also there is not the fire hazard of the powerwall with the natural gas fueled generator.

I replaced my SunPower (actually a Sonny Boy rebranded) inverter that failed in September of 2022 with a Solis inverter I bought online. The Solis is far superior to current offerings from Sunpower and others and Solis provides but a modern interface to the inverter, but also wifi for remote diagnotics over the internet as well as a smartphone app. Their field engineers are not too bright but their in-house tech support people are very knowledgeable and supportive.

All I needed was a two MPPT charge controller with a capacity of 3.7 kW or greater and these are not difficult to find for immediate purchase by anyone. Fortunately the Sunpower dealer realized that Sunpower was dragging its feet on replacing my failed inverter, agreed to install whatever inverter I bought. After communicating with Sunpower people over the past 6 months it is obvious that it would be foolish to look for them for support. I paid for an extended warranty and that turned out to be a complete waste of money.

Something I failed to appreciate when it came time to replace my failed inverter was that in my area the solar installation businesses do not do any work on a system they did not themselves install. I had 4 different local companies refuse to install a replacement inverter. That is one situation where microinverters that one can easily replace themselves would be a big advantage.

[rebelrider.mike]

I got the Emporia Vue installed a few days ago. So far it's doing well. One sensor came non functional. Emporia is sending me a new one. But I'm already getting lots of useful information.

[Ampster]

..............

Another thing is that a feature who's term I don't know is going to be pretty important to me. I'm calling it load sharing unless someone can correct me. It's the ability for the inverter to split the power being used between two inputs. As in using solar and grid vs. using solar or grid. I've read through all the manuals available for the inverters I've been researching. Some are pretty clear that they either do or don't have this feature. (But none of them actually name it.).........

There is a whole new range of load panels that have smart capabilities that can be in a subpanel so that the decision on which loads you put in which sub panel is not as important. Sometimes this feature is called smart loads and some inverters can reconfigure a bidirectional port to be used for smart loads, a generator or AC coupled solar.

This ability, along with the inverters ability to pass grid power strait through to the sub panel, will affect how many circuits I can put on the sub panel. I'd still be limited to a small number of devices during a power outage, but during normal times, I can potentially maximize my solar energy usage. I've ordered an energy monitor to help figure out how much load is on each circuit.

I use one of those Emporia Energy monitor on both my sub panels and it is one of the most cost effective devices I have purchased.

[rebelrider.mike]

I've realized a couple things. Firstly, I haven't added in the power used by the inverter to any of my calculations. Not catastrophic, but it does make a difference since it will be running 24 hr/day.

Another thing is that a feature who's term I don't know is going to be pretty important to me. I'm calling it load sharing unless someone can correct me. It's the ability for the inverter to split the power being used between two inputs. As in using solar and grid vs. using solar or grid. I've read through all the manuals available for the inverters I've been researching. Some are pretty clear that they either do or don't have this feature. (But none of them actually name it.) Other manuals are not clear at all.

This ability, along with the inverters ability to pass grid power strait through to the sub panel, will affect how many circuits I can put on the sub panel. I'd still be limited to a small number of devices during a power outage, but during normal times, I can potentially maximize my solar energy usage. I've ordered an energy monitor to help figure out how much load is on each circuit.

[rebelrider.mike]

I get what you're saying about risk management. For me, the problem is that I have no faith in any company to offer good tech support, or to honor their guarantees or warrantees. This cynicism comes from experience, unfortunately.

Generators are great. Right now I have my eye on a WEN DF875iX inverter generator. It has most of the specs I'm looking for, and replacement parts are available so I can repair it myself if it breaks. The first stage of my plan is to install it like this:
Generator.png
Generators have one fatal flaw (at least from my point of view) if there's a fuel shortage, it doesn't work. Other less important issues I have are that fuel is expensive, and inconvenient to procure. Especially in bad weather. Generators are noisy, and easily stolen. Exhaust stinks, and you have to keep putting fuel in them. None of this will keep me from buying one. But I don't want to depend on one as my sole source of backup power.

Now, if the power outage is only a couple hours; no big deal. I'll wait it out with a flashlight and a good book. If it's longer, I'll want to start the generator to cool down the fridge and freezer, and charge a few batteries before shutting it off again. That could get me by for a couple days. Longer than that though, and folks are going to be flocking to the gas station to buy all the fuel. Will the gas station be able to keep up with demand? I don't know. Remember the toilet paper shortage? And storing gasoline is not really a good idea. Propane is better for storing, but won't produce as much energy as gasoline. At least with a dual fuel generator there's an option to buy one if the other is scarce.

I haven't written here much about generators because I'm mostly trying to learn about inverters. But any generator I get must have <5% THD, be dual fuel, produce 240V split-phase, at least 6kW, and be field repairable. The only thing I don't like about the Wen is that it has an open frame despite being an inverter generator. I haven't found any other generators that fit what I want in my price range though, and I plan to build a tiny shed for it anyway.

I'm still working on how the generator, battery, solar, and energy budget are all going to work together. Here's what I've got so far:
Appliances.png
As you can see, (I hope you can see it ok) it's not complete enough to be useful yet. What I really want to find are the peak Watts, measured Watts, and how many Wh/day I might use with all the things that would be nice to run during an outage, or to run less dependent on the grid during good times.

These totals must be selective though, as not all devices will be run at the same time. The most obvious example would be space heaters and air conditioners. Also, my power usage behavior during an outage could be much different than while power is plentiful. The amount of time each device is used is just as important as how much power they use. A person could get by for a long time on a small battery if they were to budget their usage accordingly.

For example, ration power to the fridge and freezer just enough to keep the food from spoiling. Turn off the water heater completely. Don't use the microwave, space heaters, A/Cs, cloths washer, or laptops at all. Only use 1 LED light. If the internet is down, turn off the gateway/router/wifi. Have only 1 cell phone on, and don't make calls. Text and check for power grid updates only. Assuming the cellular network is even functioning. I built myself a 40 hour battery for my CPAP for camping. (I kept getting noise complaints from the bears.) I could stretch that out to a week or two of sleeping if I had to.

Then again, if gasoline and solar power are plentiful, turn everything on and have a party.

[Mike 134]

I'm one of those people that say "buy a generator" if you're looking to keep the lights on if the grid goes down. If you choose batteries, do you have enough battery power to start your well pump or furnace? What is the weather forecast for the next 5 days? Better start saving battery power if it's not clear skies. What is the lifespan of the batteries? Will you still get 50% of their rated power 10 years down the road? Just thoughts to consider for the OP.

[Ampster]

I am happy with the features of my SolArk. I found a local supplier which had a very competitive price and of course I could pick it up, which saved freight. To me it is more of a risk management decision to go with Tier 1 components with support than the less expensive variations which may not have much support. When I first started posting on this forum most people just said, buy a generator.

It all depends on where you are standing.