Inverter Selection for Off-Grid Home

[Andersonjk4]

New to the forum and glad I have found this useful resource. I am going to begin building an off-grid home this summer and am having trouble deciding on which inverter(s) to base my off-grid system on.

Some background. Located in Eastern Washington. Family of 5 with one more on the way. System will be ~16-18kW PV panels to begin (expandable to 24kW+), 48V battery bank ~30-50 kWh to start, will have a backup generator (most likely a Honeywell 22kw). I would like to design for a peak surge load of 10-12kW. Larger loads are going to be 1.5 HP well pump (Variable speed EC Motor), geothermal heatpump, heat pump water heater, Induction cooktop and electric oven (will have propane cooking options for "dark" periods), heat pump dryer, dishwasher.

Factors in my decision making:

1. Listing. I will have to get my system through permit review and electrical inspections, so UL listing in needed.
2. Reliability. This is my prime power source for my family, so it has to work without constant fussing. I travel some for work and play, so I need to be able to rely on an inverter(s) to operate as they are supposed to. Redundancy. I would rather have two or more stacked units, so a failure doesn't take down the whole system.
3. Ease of use. I would like something that is easy to operate. Example, If I am out of town my wife can easily reset a fault.
4. Features. Some features I would really like: Auto generator start/stop, Auxillary output to start a load (well pump or irrigation pump) when there is excess energy production. Remote system monitoring (wifi). Communication/integration with battery bank.
5. Customer Service.
6. Price.

From my research I think a low frequency inverter would be better as they seem more robust. Some inverters that I am considering are the Schneider XW Pro, Midnite Solar Rosie, Sol Ark 12k or 15k.

I'm sure there is more I'm missing, so that is why I am looking for input here.

 

[rodrick]

Any of those units are good quality the only problem is nobody in are area sells them or services them the nearest dealer for Schneider is backwoods in sandpoint ID so that may steer you towards Schneider I have found nothing in Spokane but a grid tied installation company and talking with them they are clueless on off grid systems so backwoods is are only real choice around here and they are good on off grid and fair prices on inverters and scc units but lifpo battery’s would have to be sourced from somewhere else they have very expensive batteries and one of the brands has a high self consumption problem

as far as inverters I would go with smaller units in parallel for redundancy so you are not totally dark if you have a issue just reduced capacity that how I went but where this system is going are nearest power pole is 10 miles but if you have grid available it might not be so important to you

good luck

 

[Andersonjk4]

I have been talking with Backwoods and they have recommended the Midnite Solar Rosie and have discouraged me from the Sol Ark for an off-grid application. My hesitation with the MN Rosie is its a fairly new inverter to the market so it doesn't have a long track record (although I have read nothing but good things about Midnite Solar in general). Also, as of right now the Rosie can't be stacked for redundancy and I am not sure about the available features compared to the Schneider.

I am around 1.5 miles from the nearest utiltiy power and was planning on bringing it to my property, but shallower than anticipated soil depth made the cost to bring power about double than anticipated ($80-$100k). And I knew I wanted to incorporate solar and a backup generator into my build anyway, so the choice to add batteries and be off-grid was a pretty easy one.

 

[rodrick]

I don’t blame you for being concerned on the Rosie it sounds like the company is going through something from what I’ve seen on other posts

did you ask about the victron units I believe there have been some changes where European listings are now recognized

 

[BentleyJ]

For Off-Grid usage, reliability & redundancy becomes the #1 concern. As far as item #3 on your wish list, ease of use is relative. The higher end, UL compliant products also have more features and a more extensive user set up menu. Translation: Takes a little longer in the beginning to set up and learn but once operational should not need constant attention and fiddling.

We have an AC coupled system with a Schneider XW+ 6848. Mostly used for back up and the occasional Peak Load Shave when we have flex alerts and so forth. Has worked perfectly for 5 years. If I was going Off-Grid, would 100% choose the Schneider XW Pro.

One of the complaints with Schneider is that the Inverter only has a built in AC charger but no Solar Charge Controllers, those are sold separately. In your case that would be a positive attribute due to the components being separated. If one component needs service or replacement it doesn't require the whole system being taken off line as would an All In One type inverter.

If planned properly, the installation space can be laid out such that you can start with 1 XW Pro, a PDP and 1 or 2 MPPT 600-100 charge controllers. Then a second XW pro and another 1 or 2 charge controllers can be added later as needed.

 

[Andersonjk4]

Thank you BentleyJ. I didn’t think about the charge controllers being separate should something need fixed/replaced. I like that. As far as features go, I would rather have something that took some time in the beginning to program and setup if it will save having to manually do things and tinker. I am all for doing maintenance and dialing in a system, but don’t want to have to go manually start a generator every time I need it etc.

When adding charge controllers to the Schneider inverters, would it be best to use Schneider MPPT charge controllers? Do they integrate with the inverter more easily than say a Midnite Solar or other brand?

 

[rodrick]

Backwoods does sell ul listed victron units now, which are a rock solid unit so there’s another option for you

 

[Andersonjk4]

I think the UL listed Victron units are only 12V and 24V on the DC input side. I’m planning my system for 48V. The larger Victron units do carry IEC listings. I have reached out to the AHJ to see if they will accept the IEC listings in a stand alone system.

 

[BentleyJ]

When adding charge controllers to the Schneider inverters, would it be best to use Schneider MPPT charge controllers? Do they integrate with the inverter more easily than say a Midnite Solar or other brand?

Absolutely, the Schneider charge controllers are Xanbus compatible as is the Pro inverter and the InsightHome which collects all the data and makes it available on your network and insight cloud. The Schneider Automatic Gen Start is also Xanbus compatible but many times is not needed as the Aux relay on the inverter can be used for the same purpose although with with less set up options.

 

[Andersonjk4]

I received word back from the AHJ in my area and they won’t accept the Victron ISO listings. Washington State L&I who administers electrical permits and inspections maintains a list of acceptable testing agencies. And the agency who did the testing for the Victrons is not accepted.

As of now, I am leaning heavily toward the Schneider XW Pro. Seems like it checks most all of my boxes. I will likely start with two inverters and 2 MPPT with a plan to add a 3rd of each when I get the main house finished. Now I need to decide on batteries, panels and a generator.

 

[Rednecktek]

I received word back from the AHJ in my area and they won’t accept the Victron ISO listings. Washington State L&I who administers electrical permits and inspections maintains a list of acceptable testing agencies. And the agency who did the testing for the Victrons is not accepted.

As of now, I am leaning heavily toward the Schneider XW Pro. Seems like it checks most all of my boxes. I will likely start with two inverters and 2 MPPT with a plan to add a 3rd of each when I get the main house finished. Now I need to decide on batteries, panels and a generator.

I'd love to get that list from them. So often they'll tell you "Nope, not accepted" and when you ask the answer tends to be "The ones we approved of." Gee, that helps.

 

[Andersonjk4]

Here is a link to the page on L&I's website listing the approved testing laboritories.

https://lni.wa.gov/licensing-permit...ation#accredited-product-testing-laboratories

 

[Rednecktek]

Now if we could just get a list of approved units somehow, but I have a feeling that would be hours of cross referencing every brand with every jurisdiction's testing list... sigh.

 

[S610]

I have been talking with Backwoods and they have recommended the Midnite Solar Rosie and have discouraged me from the Sol Ark for an off-grid application.

What reasons did they give regarding Sol-Ark for off-grid?

 

[BlindBadger]

Now if we could just get a list of approved units somehow, but I have a feeling that would be hours of cross referencing every brand with every jurisdiction's testing list... sigh.

I’m going through the same thing, also in eastern WA. Generally I’m seeing CSA, Tüv, or UL for the gear. I’m also going to go with the Schneider.