Best Inverter setup

[wyosolar]

Hello,

I am new to the forum and a noob to the solar realm. Spent some time researching this forum for answers but decided to post for a more specific response from all of you in the know. I am in the early stages of planning a DIY off grid solar build for my rural property. I am looking for recommendations of which brand/type/model of inverters and solar charge controllers to go with. I would like to see your thoughts based upon the below criteria:

• DIY friendly (this will be my first install, but I do have technical aptitude) install and programming. I know the Sol-Ark and other All-in ones are easier and faster to install, but I am willing to do a more complicated and longer install if the end goal is a better product and setup.
• I plan on starting with 8-12KW of Solar PV input with the option of expansion in the future. These will be roof top mounted.
• Batteries will be Lithium with 60KWH of capacity and the option of expansion in the future.
• Going off-of my current KWH usage I am basing the above specs off of an average of 740KWH/Month or 25KWH/Day with a possible one-month spike in the winter of 1200KWH/Month (I live in WY)
• I need an inverter that has the capability to do an auto start for a diesel generator. I plan on using a backup diesel generator to help supplement by energy needs in the winter until I can afford more PV panels and batteries.
• An inverter that can handle surge and big draws from big starts like air compressor, 240V welder, shop tools, electric dryer, 240v well pump, etc. I have heard that the High Frequency transformer less inverters struggle with this as well as leg imbalances whereas Low Frequency Transformer types do not.
• This is for an off-grid application, but there is a slim chance in the future for grid tie so it may make sense to have the option for grid tie backup and pass through.
• An Inverter company that has good tech support or distributor that can help with programming issues and the likes.
• Longevity and build quality (I don’t want to have to do this again for many years to come and I don’t want something I have to tinker with once it is setup, I want it to just run).
• I don’t care if it is an All in one or not.
• Size and space don’t matter has I have the room.
• Price is always important, but I am willing to pay more if it is a better product and it make sense too.

I am leaning towards Schneider Electric’s XW Pro 6.8 or a Victron Quattro 10KVA (I could stack two units for more output), or an all in one like the Sol-Ark 15KW. I am open to other brands like SMA Sunny Island, Midnite solar, Outback Radian, etc. I just haven’t seen as much exposure to those other brands, so I don’t know how they would be for a DIYer like myself? Like I mentioned, I am open to whatever and respect your recommendation from what you have seen, used, and built over the years.

I appreciate any thoughts on the matter.

 

[BentleyJ]

Your thinking is sound with regard to performance-reliability and using higher end equipment. For the use case you've described with large loads and inductive surges you can't go wrong with XW Pro. I can attest to the XW+ and its capabilities. That said, an honest assessment of Schneider would have to include the much more complex and time consuming installation process of all the separate components.
You would probably be looking at 2 XW Pros, PDP, 2 charge controllers, InsightHome, maybe an AGS.
On the other hand, having separate components and 2 inverters for an off-grid system offers greater redundancy.

As far as High Frequency vs. Low Frequency inverters. It is generally true that having a big copper transformer is desirable for surge loads but the Sol-Ark 15K has a good reputation for performance and customer service. Also having all the wiring connections built into the lower panel really simplifies installation. The down side is everything is in one package and any problem that is not field serviceable requires removal of basically your whole system except for the PV's. For off-grid it would make sense to have 2 which is a $14,000 investment.

 

[wyosolar]

Thank you for your response and insight. Those are my thoughts as well. Any good resources on wiring and programming up the XW Pro? I have heard negative reviews when it comes to support for Schneider. Which vendors have you found that offers good support for the XW Pro?

 

[sumpower]

Most of my solar income as an electrical contractor came from people not reading and following the written instructions when installing thier equipment. In most cases it was obvious that they decided to just become overwhelmed by the information instead of systematically completing one task at a time, then moving to the next.

I've said this before, anyone with a mechanical aptitude can complete a full solar install with minor correction from an inspector if they install the system according to the manufacturers written instructions. Its time consuming for someone on thier first go around, always more time consuming than was planned for. Just my experience when talking to customers as well as my first install experience as an electrical contractor.

By your organized/concise criteria above I have no doubt you can do an install.
My main experience has been with Outback and Midnite Solar, both to me have always had good customer support with thier products.
Very limited experience with Schneider and thier customer support has gotten better lately. All my Schneider service calls were customer made problems. The equipment itself from the three manufacturers I mention are rock solid. I know you would be happy with any of the three.

I personally prefer (my opinion) the individual components pieced together to make a system, as the heat management is done for each individual component of the system.

The Schneider XW charge controllers win the for me when the solar array is more than 150 feet from the charge controller. 600 volt max array string voltage for less voltage drop and smaller wire size, smaller conduit size. For less cost on that portion of the system.
I only have one Sol-Ark install, a 12K inverter. The system has run without any issues for three years. Flawless grid tie install. It is the only grid tie system I have ever installed.

My home system is an 8K Outback Radian off grid, have not had any problems with it.

 

[sumpower]

I reread your post, and the 60Kw Lithium battery bank stood out to me. One of the advantages of the Schneider equipment is the "closed loop" feature I believe they have with 5 different battery manufacturers. The ability to get the Lithium batteries charged faster in the "closed loop" function would be a plus for you. Over 20% reduction in time it takes to charge a battery vs "open loop" charging.

Discover & Schneider Electric Solar - closed-loop comms over Xanbus

LYNK© closed-loop communication between Discover AES LiFePO4 batteries and Schneider Electric’s Conext SW and Conext XW+ inverter systems over Xanbus

blog.discoverbattery.com

I know that the Outback Radian does not have a "closed loop" function to charge Lithium batteries.

 

[wyosolar]

Thanks for the reply. Any good vendors that are good tonwork with for the XW Pro?

 

[JBertok]

A Dual-XW Pro system will have the most complex commissioning procedure of all of your options, however it will give you the most control and flexibility too. You can easily stack 2 XW-Pros in split-phase mode. In that configuration both XW Pros produce split phase unlike other manufactures that dedicate each inverter to a phase.

A Triple-XW Pro configuration allows you to have them all in split-phase mode or in 3-phase mode. (An external relay is usually require with 3+ units in split-phase mode but might actually not be needed since you're not grid connected.

Schneider MPPT controllers allow for generously overprovisioning the array capacity, as long as the PV open circuit voltage does not exceed spec. This really helps extend the area under the production curve of each day, and also helps with cloudy days.

In self-supporting your system you should only need the manufacture if there is a warrantied failure. Reading through the various failure posts here you'll see that certain manufactures of certain products have a long and storied history of selling cheap and extremely problematic fundamentally flawed equipment - Schneider is at the opposite end of the spectrum from that class of junk. The documentation for commissioning is a little scattered, and some of it was written in the era of the XW+ but is still relevant to the XW Pro. Any configuration questions you have can be answered more efficiently and quickly right here on this forum that through vendor support. Vendor resources are best reserved for "problems".

The discussions about low-frequency inverters versus high-frequency for inductive loads is absolutely relevant to your use-case. So too is surge capacity. Anybody with a shop or barn full of tools isn't going to be adequately served by any of the high-frequency inverter choices out there; that's my opinion.

 

[1201]

The victron quattro 10k is a 120v machine so you would need two for 240v capabilities. Same thing with sma sunny island

They don't make the sunny island any longer but you can still buy them new and two of them will do everything you want to do and more. I'm not sure about the warranty though. The good thing is you can find them new cheaper than any of the other low frequency inverters(quattro, xw pro) and they are also very well priced used.

The setup you are going for is very similar to mine:
11.2kw of pv, 57kwh of batteries and a grid tie inverter for the mppts. This system has been rock solid with no issues even though the inverters are 12 years old.

I did a thing! Sunny Island, growatt min ac coupled system

hi guys, I finally got my system set up after 1 SOLID year of researching solar PV here there and everywhere and 5 years of solar home building research and planning. I built my passive solar house with pv in mind. No penetrations on the south side. The optimizer said 32° roof angle facing 4...

diysolarforum.com

There is only one thing I'm not 100% happy with and it only concerns feeding to the grid. If the sunny island connects to the grid for backfeed it also charges the batteries and powers loads from the grid. I can limit how much it charges the batteries from the grid but it will always power loads from pv and or the grid as available.

Well, since I want to use my battery at night, pv during the day, I have to manually switch the grid in and out every day so that when the battery is full I can export to the grid from pv and then disconnect when the sun goes down so I can discharge my batteries. But giving the quality of these units I'm perfectly happy to do that.
I also suspect all the other low frequency inverter act this way but I'm not sure

 

[wyosolar]

Thanks for the feedback. What batteries are you/everybody is using? Been looking at EG4s, though I know some love and others loathe them. Open to any input.

 

[1201]

Thanks for the feedback. What batteries are you/everybody is using? Been looking at EG4s, though I know some love and others loathe them. Open to any input.

Without a doubt, build your own batteries. It's half the price of assembled batteries.

16 280ah cells. I used batteryhookup.com approx $110 each. Comes with busbars

200a jk bms $120 or so

Nader breaker $30

Random Junctions, lugs etc $100

You can do your 60kwh for less than $9000

 

[wyosolar]

Thank you. I know DoD and other factors come into play, but what is an average life span yrs/cycles for a diy battery build like this? And what resources would you recommend to learn how to do this?

 

[1201]

Thank you. I know DoD and other factors come into play, but what is an average life span yrs/cycles for a diy battery build like this? And what resources would you recommend to learn how to do this?

The same as a prebuilt battery.

Resources- you'll have to spend a lot of time here and ask a lot of questions and read the resources section

 

[wyosolar]

Thank you

 

[wyosolar]

Did you make your own battery box or buy a pre-made unit like Seplos? And would the JK BMS communication closed loop to Schneider XW Pro. If not, what diy BMS would?

 

[1201]

Did you make your own battery box or buy a pre-made unit like Seplos? And would the JK BMS communication closed loop to Schneider XW Pro. If not, what diy BMS would?

Hi. I built my own box out of a couple of pieces of plywood. The money I saved on a battery box went into more batteries.

I don't use closed loop comms with my sunny islands sorry

 

[wyosolar]

I am assuming that the JK BMS is using Bluetooth or something so you can use an app on your phone or computer to look at each individual cells? How are you monitoring and communicating with your batteries and inverters to know what SOC and other data, if not closed loop?

 

[1201]

I am assuming that the JK BMS is using Bluetooth or something so you can use an app on your phone or computer to look at each individual cells? How are you monitoring and communicating with your batteries and inverters to know what SOC and other data, if not closed loop?

Jk bms has Bluetooth.

You don't need communications- you can use voltage.

For soc I use a victron shunt with solar assistant so I can see the soc from anywhere in the world if I have an Internet connection

 

[wyosolar]

Very nice, thanks for the advice.

 

[hwy17]

I went with the XW and I'm not unhappy with it, but if I was starting over I would seriously consider a Rosie and Barcelona. Mostly for the culture. The XW is a product of the same culture, but bought out and produced by a somewhat uncaring parent company now. Midnite is the last bastion.

But I don't have the experience to say I would end up happy with that decision. Midnite has had periods in recent with a questionable pace of development.

 

[wyosolar]

Not happy with the product itself or the tech support?