I'm about ready to give up on solar

[1201]

Tl:Dr is there no aio that connects to the main panel just like a grid tie?


Long story:
I had paid an engineer for a design for a grid tied system then the utility removed net metering and doing the math grid tied doesn't make sense anymore.

Now I just want a system that will pull simultaneously from the grid, and/or solar panels, and/or battery to power a 200 amp panel, without selling even one kw to the utility. The system will be grid connected 99% of the time

Its an all electric home with well pump, septic pump, 3 ac systems(mini splits) , electric water heater etc. Etc

So far all I'm finding are units that get power from the main disconnect and send power to a sub panel, usually limited to 50a or less. Ie not enough to power close to 200a if needed

I'm also reading about a lot of problems and faults with many of the popular inverters and that's making me question if I should even continue down this road.

It seems the sol-ark 15k will do what I need since it will pass through 200 amps but the price tag is up there and there are several threads discussing problems.

The Schneider Xw pro seems to be rock solid but can only handle 60 amps ac input? So I would need three?

Is there no affordable all in one solution that connects to a main panel like a grid tie inverter and would provider up to 200a? Heck I'll even settle for 150a.

Thanks

 

[Nobodybusiness]

Tl:Dr is there no aio that connects to the main panel just like a grid tie?


Long story:
I had paid an engineer for a design for a grid tied system then the utility removed net metering and doing the math grid tied doesn't make sense anymore.

Now I just want a system that will pull simultaneously from the grid, and/or solar panels, and/or battery to power a 200 amp panel, without selling even one kw to the utility. The system will be grid connected 99% of the time

Its an all electric home with well pump, septic pump, 3 ac systems(mini splits) , electric water heater etc. Etc

So far all I'm finding are units that get power from the main disconnect and send power to a sub panel, usually limited to 50a or less. Ie not enough to power close to 200a if needed

I'm also reading about a lot of problems and faults with many of the popular inverters and that's making me question if I should even continue down this road.

It seems the sol-ark 15k will do what I need since it will pass through 200 amps but the price tag is up there and there are several threads discussing problems.

The Schneider Xw pro seems to be rock solid but can only handle 60 amps ac input? So I would need three?

Is there no affordable all in one solution that connects to a main panel like a grid tie inverter and would provider up to 200a? Heck I'll even settle for 150a.

Thanks

You are probably not ever pulling 200 amps on that panel.

It’s rated at 200 amps but that doesn’t mean you are using 200 amp.

Get an emporia Energy monitor and do an energy audit.

Then you can narrow down what you want to do and use.

You can parallel certain inverters if you need too.
Not all are Sol-Ark.
The 15k is new so has some firmware growing pains to go through.

I have a 400 amp service and use 2 Sol-ark 12ks with no issues.

 

[GXMnow]

I agree that you need to do a real energy audit. Also look at the surge power of the well pump and other things you might want to run during a blackout.

In your case, knowing what I do after using my XW-Pro for 2 years, I would go with an XW-Pro and an MPPT 600/100 charge controller with a decent sized battery bank and get the Watt-Node power meter and Insight Home.

The XW-Pro will connect to the main panel, and the Watt-Node will monitor the power at the grid connection. You can add a sub panel for loads you want to be able to run during a power failure. But the XW will be able to push up to 6,800 watts back to the main panel and the Watt-Node will keep it from exporting to the grid by limiting the push to what is being used in the main panel. If you do draw more than 6,800 watts, or you run the battery down, it will take grid power. If you find this is not enough, you can add a second XW-Pro. The backup loads panel can have up to 60 amps of load in it, but keep in mind that it will only have 28 amps available from battery during a grid failure with just one XW.

 

[1201]

You are probably not ever pulling 200 amps on that panel.

It’s rated at 200 amps but that doesn’t mean you are using 200 amp.

Get an emporia Energy monitor and do an energy audit.

Then you can narrow down what you want to do and use.

You can parallel certain inverters if you need too.
Not all are Sol-Ark.
The 15k is new so has some firmware growing pains to go through.

I have a 400 amp service and use 2 Sol-ark 12ks with no issues.

How are you using 2 12ks with 400 amp service? Do you have all your loads powered by the solark?

 

[1201]

I agree that you need to do a real energy audit. Also look at the surge power of the well pump and other things you might want to run during a blackout.

In your case, knowing what I do after using my XW-Pro for 2 years, I would go with an XW-Pro and an MPPT 600/100 charge controller with a decent sized battery bank and get the Watt-Node power meter and Insight Home.

The XW-Pro will connect to the main panel, and the Watt-Node will monitor the power at the grid connection. You can add a sub panel for loads you want to be able to run during a power failure. But the XW will be able to push up to 6,800 watts back to the main panel and the Watt-Node will keep it from exporting to the grid by limiting the push to what is being used in the main panel. If you do draw more than 6,800 watts, or you run the battery down, it will take grid power. If you find this is not enough, you can add a second XW-Pro. The backup loads panel can have up to 60 amps of load in it, but keep in mind that it will only have 28 amps available from battery during a grid failure with just one XW.

Hi thanks for this information. Can you clarify what you mean by the xw pro connecting to the main panel? Do you mean the output of the xw pro connects to a back feed breaker on the actual main panel? Because if that's the case that would be exactly what I'm trying to do.

 

[GXMnow]

Hi thanks for this information. Can you clarify what you mean by the xw pro connecting to the main panel? Do you mean the output of the xw pro connects to a back feed breaker on the actual main panel? Because if that's the case that would be exactly what I'm trying to do.

Yes, the XW-Pro can back feed to the breaker in the main panel. I had mine running like that only for about 2 months before I installed my backup loads panel. The obvious limitation is that the grid has to be good for it to back feed to the main. It has 2 separate inputs, AC1 and AC2. The AC1 is for the grid feed and it can back feed to AC1. The AC2 input is meant for a generator and it will not back feed to that. The load output side is the only terminals that will get power during a grid outage.

Here is their web page about it.

XW Pro 120/240V

The Schneider Electric XW Pro 6848 solar inverter provides flexible design with optional generator integration for home and small businesses.

solar.se.com

The Schneider system is not perfect, but if I was building a system from scratch again, I think I would still go with the XW-Pro inverter. It is a beast. The hardware is rock solid and it will crank crazy power. It will surge to 12,000 watts until it gets too hot. IT will run over 8,000 watts for 30 minutes. And it handles unbalanced loads without complaint.

My biggest complaints are that it does not work on it's own in an AC coupled system with existing grid tied solar. They claim it does, but it is lacking software to do that properly. And all of my solar was existing grid tie microinverters. Schneider's best fix was to re-wire the solar panels to a DC charge controller. I won't do that. I am now using an external PLC (Programmable Logic Controller) which commands the XW-Pro inverter when to charge the batteries. But if I was doing a new install I would now go with at least half of the solar array being DC with an MPPT charge controller. If you do not have any solar yet, this should not be an issue for you to do. A single Schneider MPPT 100-600 will accept up to a 7,000 watt array of solar panels at up to 600 volts.

The MPPT will take as much power as it can from the solar panels and just keep stuffing it into the batteries. If the batteries do become full, it will dial back the current and just keep them full, even if the inverter is pulling power. That batteries will not start discharging until the sun goes down and can't supply enough power any more.

So then the XW-Pro inverter never goes into charge mode. It will just invert battery power to AC and supply the power to the backup loads panel and to the main panel as needed. If the battery does run too low, it will go into "AC pass through" mode and wait until the batteries charge up again.

I was doing a complete new install, I think I would still use a few of the microinverters again though. While the MPT DC charging is more efficient and robust for energy into the battery system and XW-Pro inverter, the Microinverters are more efficient at making AC power that you will use while the sun is up. when you do your energy audit, think about how much power you use from 10 am to 4 pm and then think about the power used while the sun is down from 5 pm to 7 am. For my house, I would like about 3,500 watts of ac daytime power, and 3,500 wats of DC charging the battery for night time power.

You should also look up how much solar insolation (sun hours) you can expect for your location and panel angles. I use the calculators at this site.

The Solar Electricity Handbook - 2019 Edition

The Solar Electricity handbook - 2019 Edition - is a simple, practical book to using electric solar panels and designing and installing photovoltaic solar PV systems.

www.solarelectricityhandbook.com

They are not perfect, but it will get you close.

 

[Mattb4]

Tl:Dr is there no aio that connects to the main panel just like a grid tie?


...

The answer is no. Something can not be like a grid tie (being in parallel with the grid) and not be a grid tie. It can be setup to do zero export or it is a off grid inverter setup. Can you do a breaker interlock or transfer switch arrangement for using power from one or the other source to power the main panel? Yes, but not both at the same time.

Any inverter that parallels with the grid is going to need a utility interconnect agreement. It does not matter that you never intend to send a watt upstream the fact is once your system parallels with the grid it has the potential to power the grid.

 

[Shimmy]

The answer is no. Something can not be like a grid tie (being in parallel with the grid) and not be a grid tie. It can be setup to do zero export or it is a off grid inverter setup.

In a nutshell this is the issue. I get the concern, though. Personally I have a 200A main panel that feeds 6 loads (two sub-panels and three AC units, plus my existing microinverters). So, if I want battery backup for the home there is no way to avoid a new panel. My options are a new utility panel, or a new downstream "main" panel that everything in the existing panel gets re-fed from. The utility panel then gets a breaker for the AIO and for the bypass.

If I went with the XW-Pro, I would need to live with some loads not getting battery backup (connected directly to the existing main panel) and a lot of re-wiring due to the 60A limitation. The 60A was almost workable, but this winter our loads have peaked over 75A for two hours when we had guests staying with us. I could get it down to under 60A with some work, but I could not work within the power limitations of the XW-Pro. With the extra work on the 60A limit and a second XW-Pro I would be fine... but then you are approaching the price point of the Sol-Ark 15k.

I will likely end up going with the 15k since I don't think I have the wall space needed for the Schneider solution with two inverters. I definitely cannot pull it off if I have to add an external transfer switch. I hate picking a lesser product, but making it more foolproof makes sense for me.

 

[1201]

Yes, the XW-Pro can back feed to the breaker in the main panel. I had mine running like that only for about 2 months before I installed my backup loads panel. The obvious limitation is that the grid has to be good for it to back feed to the main. It has 2 separate inputs, AC1 and AC2. The AC1 is for the grid feed and it can back feed to AC1. The AC2 input is meant for a generator and it will not back feed to that. The load output side is the only terminals that will get power during a grid outage.

Here is their web page about it.

XW Pro 120/240V

The Schneider Electric XW Pro 6848 solar inverter provides flexible design with optional generator integration for home and small businesses.

solar.se.com

The Schneider system is not perfect, but if I was building a system from scratch again, I think I would still go with the XW-Pro inverter. It is a beast. The hardware is rock solid and it will crank crazy power. It will surge to 12,000 watts until it gets too hot. IT will run over 8,000 watts for 30 minutes. And it handles unbalanced loads without complaint.

My biggest complaints are that it does not work on it's own in an AC coupled system with existing grid tied solar. They claim it does, but it is lacking software to do that properly. And all of my solar was existing grid tie microinverters. Schneider's best fix was to re-wire the solar panels to a DC charge controller. I won't do that. I am now using an external PLC (Programmable Logic Controller) which commands the XW-Pro inverter when to charge the batteries. But if I was doing a new install I would now go with at least half of the solar array being DC with an MPPT charge controller. If you do not have any solar yet, this should not be an issue for you to do. A single Schneider MPPT 100-600 will accept up to a 7,000 watt array of solar panels at up to 600 volts.

The MPPT will take as much power as it can from the solar panels and just keep stuffing it into the batteries. If the batteries do become full, it will dial back the current and just keep them full, even if the inverter is pulling power. That batteries will not start discharging until the sun goes down and can't supply enough power any more.

So then the XW-Pro inverter never goes into charge mode. It will just invert battery power to AC and supply the power to the backup loads panel and to the main panel as needed. If the battery does run too low, it will go into "AC pass through" mode and wait until the batteries charge up again.

I was doing a complete new install, I think I would still use a few of the microinverters again though. While the MPT DC charging is more efficient and robust for energy into the battery system and XW-Pro inverter, the Microinverters are more efficient at making AC power that you will use while the sun is up. when you do your energy audit, think about how much power you use from 10 am to 4 pm and then think about the power used while the sun is down from 5 pm to 7 am. For my house, I would like about 3,500 watts of ac daytime power, and 3,500 wats of DC charging the battery for night time power.

You should also look up how much solar insolation (sun hours) you can expect for your location and panel angles. I use the calculators at this site.

The Solar Electricity Handbook - 2019 Edition

The Solar Electricity handbook - 2019 Edition - is a simple, practical book to using electric solar panels and designing and installing photovoltaic solar PV systems.

www.solarelectricityhandbook.com

They are not perfect, but it will get you close.

Thanks very much! this is very promising. If I can use it like you did for two months, feeding the main panel and pulling energy from the grid as needed, I think it should be the solution. I did see a video about the lack of true ac coupling- I don't have a system yet so that doesn't really apply to me.

 

[Zwy]

Find inverters that are stackable. If the inverter model is 60A, stacking 2 per leg gives you 120A per leg. 3 units per leg and 180A per leg.

I'd first install a monitor and see what peak amp draw is. Adjust circuits in main panel to achieve the best balance if you see one leg has a much higher amp draw. The largest I saw in my house this time of year is 7Kw (60A) and I moved one circuit to the other phase and now that phase is 4Kw (33A) max.

 

[1201]

The answer is no. Something can not be like a grid tie (being in parallel with the grid) and not be a grid tie. It can be setup to do zero export or it is a off grid inverter setup. Can you do a breaker interlock or transfer switch arrangement for using power from one or the other source to power the main panel? Yes, but not both at the same time.

Any inverter that parallels with the grid is going to need a utility interconnect agreement. It does not matter that you never intend to send a watt upstream the fact is once your system parallels with the grid it has the potential to power the grid.

Hi thanks for this information. when you say no, do you just mean it would be a grid tie system and I would need an interconnect agreement? If that's what you mean I'm ok with that. I already paid an engineer who can design such a system for me for permitting purposes.

if you mean the inverter cannot backfeed the main panel then that is a bigger problem. but then my question would be how are the all-in-ones/ hybrid inverters able to sell back to the grid if they cannot back-feed the grid

regarding your other idea about a transfer switch, i admit that I havent looked into that as I didnt know it was an option. how do they work? would I be charging the battery during the day when my use is low and production is high, then manually switching to the battery when the sun goes down? thanks

 

[1201]

Find inverters that are stackable. If the inverter model is 60A, stacking 2 per leg gives you 120A per leg. 3 units per leg and 180A per leg.

I'd first install a monitor and see what peak amp draw is. Adjust circuits in main panel to achieve the best balance if you see one leg has a much higher amp draw. The largest I saw in my house this time of year is 7Kw (60A) and I moved one circuit to the other phase and now that phase is 4Kw (33A) max.

thanks for the input. that actually seems like a workable idea. so I would have a 60 amp breaker going from main panel to each one and then the output of each one going to the same subpanel? do you have any inverter you recommend? thanks

 

[Mattb4]

Hi thanks for this information. when you say no, do you just mean it would be a grid tie system and I would need an interconnect agreement? If that's what you mean I'm ok with that. I already paid an engineer who can design such a system for me for permitting purposes.

if you mean the inverter cannot backfeed the main panel then that is a bigger problem. but then my question would be how are the all-in-ones/ hybrid inverters able to sell back to the grid if they cannot back-feed the grid

regarding your other idea about a transfer switch, i admit that I havent looked into that as I didnt know it was an option. how do they work? would I be charging the battery during the day when my use is low and production is high, then manually switching to the battery when the sun goes down? thanks

If you do not mind having a utility approved setup than there are various grid tie hybrid units such as the Sol-Arks.

The Inverter does not backfeed the Main panel if it is operating as an alternative source, either from a transfer switch or breaker interlock setup. You have to turn off one power source and turn on the other to feed the Main. Automatic transfer switches do this upon loss off one power input such as grid or inverter. Some people using a breaker interconnect device will refer to the breaker used to provide power to the main panel when it is on and the Main breaker is off as back feeding the panel. It is not a accurate description.

Most AIO's incorporate auto transfer switches. Just for clarity let me give you a simple block diagram for this.

 

[Zwy]

thanks for the input. that actually seems like a workable idea. so I would have a 60 amp breaker going from main panel to each one and then the output of each one going to the same subpanel? do you have any inverter you recommend? thanks

That would be correct. 60A breaker for each inverter. For 120A per leg would require 4 inverters.

I have the EG4 6500EX, the LV6548 from MPP Solar is the same inverter however the SCC is only 250V PV VOC rated on the LV6548 compared to the EG4 6500EX which is 500V VOC rated. The LV6548 is used by DMI as he put his system together before the EG4 6500EX was released.

It's all a matter of choice and how deep the pocketbook is. If you go with high end products with a high price tag, the payback period will be greatly extended. There is plenty of information in this forum to help you make a decision on which way to go. It will take some research on your part to decide what is right for you. Search the archives, learn as much as you can and then develop a plan before purchasing a single item.

 

[1201]

If you do not mind having a utility approved setup than there are various grid tie hybrid units such as the Sol-Arks.

The Inverter does not backfeed the Main panel if it is operating as an alternative source, either from a transfer switch or breaker interlock setup. You have to turn off one power source and turn on the other to feed the Main. Automatic transfer switches do this upon loss off one power input such as grid or inverter. Some people using a breaker interconnect device will refer to the breaker used to provide power to the main panel when it is on and the Main breaker is off as back feeding the panel. It is not a accurate description.

Most AIO's incorporate auto transfer switches. Just for clarity let me give you a simple block diagram for this.

Hi thanks. So using the grid tied inverter without a transfer switch can I back feed the main panel and simultaneously power circuits on the main panel with power from solar and grid? Thanks

 

[Zwy]

Hi thanks. So using the grid tied inverter without a transfer switch can I back feed the main panel and simultaneously power circuits on the main panel with power from solar and grid? Thanks

Only if the inverter has the capability to phase shift to match grid.

For the hybrids designed for grid tie, it simply is a matter of zero export setting and the loads can be shared between grid and inverter. Usually however this comes at a cost in the unit will always have to draw from grid enough power to keep the unit from backfeeding to grid.

As for just utilizing one main panel, it usually is better to make the current main panel a distribution panel fed thru the inverter and have a service panel before that that contains N-G bond. In my system I installed a 3 pole transfer double throw manual switch which allows me to switch completely back to grid and bypass the inverters.

 

[1201]

In a nutshell this is the issue. I get the concern, though. Personally I have a 200A main panel that feeds 6 loads (two sub-panels and three AC units, plus my existing microinverters). So, if I want battery backup for the home there is no way to avoid a new panel. My options are a new utility panel, or a new downstream "main" panel that everything in the existing panel gets re-fed from. The utility panel then gets a breaker for the AIO and for the bypass.

If I went with the XW-Pro, I would need to live with some loads not getting battery backup (connected directly to the existing main panel) and a lot of re-wiring due to the 60A limitation. The 60A was almost workable, but this winter our loads have peaked over 75A for two hours when we had guests staying with us. I could get it down to under 60A with some work, but I could not work within the power limitations of the XW-Pro. With the extra work on the 60A limit and a second XW-Pro I would be fine... but then you are approaching the price point of the Sol-Ark 15k.

I will likely end up going with the 15k since I don't think I have the wall space needed for the Schneider solution with two inverters. I definitely cannot pull it off if I have to add an external transfer switch. I hate picking a lesser product, but making it more foolproof makes sense for me.

Yes, the XW-Pro can back feed to the breaker in the main panel. I had mine running like that only for about 2 months before I installed my backup loads panel. The obvious limitation is that the grid has to be good for it to back feed to the main. It has 2 separate inputs, AC1 and AC2. The AC1 is for the grid feed and it can back feed to AC1. The AC2 input is meant for a generator and it will not back feed to that. The load output side is the only terminals that will get power during a grid outage.

Here is their web page about it.

XW Pro 120/240V

The Schneider Electric XW Pro 6848 solar inverter provides flexible design with optional generator integration for home and small businesses.

solar.se.com

The Schneider system is not perfect, but if I was building a system from scratch again, I think I would still go with the XW-Pro inverter. It is a beast. The hardware is rock solid and it will crank crazy power. It will surge to 12,000 watts until it gets too hot. IT will run over 8,000 watts for 30 minutes. And it handles unbalanced loads without complaint.

My biggest complaints are that it does not work on it's own in an AC coupled system with existing grid tied solar. They claim it does, but it is lacking software to do that properly. And all of my solar was existing grid tie microinverters. Schneider's best fix was to re-wire the solar panels to a DC charge controller. I won't do that. I am now using an external PLC (Programmable Logic Controller) which commands the XW-Pro inverter when to charge the batteries. But if I was doing a new install I would now go with at least half of the solar array being DC with an MPPT charge controller. If you do not have any solar yet, this should not be an issue for you to do. A single Schneider MPPT 100-600 will accept up to a 7,000 watt array of solar panels at up to 600 volts.

The MPPT will take as much power as it can from the solar panels and just keep stuffing it into the batteries. If the batteries do become full, it will dial back the current and just keep them full, even if the inverter is pulling power. That batteries will not start discharging until the sun goes down and can't supply enough power any more.

So then the XW-Pro inverter never goes into charge mode. It will just invert battery power to AC and supply the power to the backup loads panel and to the main panel as needed. If the battery does run too low, it will go into "AC pass through" mode and wait until the batteries charge up again.

I was doing a complete new install, I think I would still use a few of the microinverters again though. While the MPT DC charging is more efficient and robust for energy into the battery system and XW-Pro inverter, the Microinverters are more efficient at making AC power that you will use while the sun is up. when you do your energy audit, think about how much power you use from 10 am to 4 pm and then think about the power used while the sun is down from 5 pm to 7 am. For my house, I would like about 3,500 watts of ac daytime power, and 3,500 wats of DC charging the battery for night time power.

You should also look up how much solar insolation (sun hours) you can expect for your location and panel angles. I use the calculators at this site.

The Solar Electricity Handbook - 2019 Edition

The Solar Electricity handbook - 2019 Edition - is a simple, practical book to using electric solar panels and designing and installing photovoltaic solar PV systems.

www.solarelectricityhandbook.com

They are not perfect, but it will get you close.

hey I just found some promising information- look at page 7/16 of this document, under

Figure 2DC Coupled PV System – Self Supply Entire Home (backup loads sub-panel and main panel)

https://solar.se.com/us/wp-content/uploads/sites/7/2021/08/TP202004_Conext-XW-Pro-Self-supply-and-Grid-Sell-Limiting-Solution-Guide-990-91371_rev-A.pdf

it looks like the what you described. thanks!

 

[1201]

Only if the inverter has the capability to phase shift to match grid.

For the hybrids designed for grid tie, it simply is a matter of zero export setting and the loads can be shared between grid and inverter. Usually however this comes at a cost in the unit will always have to draw from grid enough power to keep the unit from backfeeding to grid.

As for just utilizing one main panel, it usually is better to make the current main panel a distribution panel fed thru the inverter and have a service panel before that that contains N-G bond. In my system I installed a 3 pole transfer double throw manual switch which allows me to switch completely back to grid and bypass the inverters.

so would you say all zero export hybrids can do this?
i have a main disconnect that has the neutral and ground bond so the main panel is not bonded. so i wouldnt need a separate service panel right? thanks

 

[EastTexCowboy]

Only if the inverter has the capability to phase shift to match grid.

For the hybrids designed for grid tie, it simply is a matter of zero export setting and the loads can be shared between grid and inverter. Usually however this comes at a cost in the unit will always have to draw from grid enough power to keep the unit from backfeeding to grid.

As for just utilizing one main panel, it usually is better to make the current main panel a distribution panel fed thru the inverter and have a service panel before that that contains N-G bond. In my system I installed a 3 pole transfer double throw manual switch which allows me to switch completely back to grid and bypass the inverters.

That's exactly what I did on mine with a Siemens three pole double throw transfer switch. Mine are the MPP LV6548 but otherwise very similar setup.

 

[Hedges]

thanks for the input. that actually seems like a workable idea. so I would have a 60 amp breaker going from main panel to each one and then the output of each one going to the same subpanel? do you have any inverter you recommend? thanks

This works, but you don't get the full 60A + 60A = 120A because current splits the way it wants to based on resistance.

My Sunny Island system is set up this way, originally with 70A QO breakers, and inverters allow up to 56A through relays.
There was 60' of 6 awg wire in each path, exactly matched. Pass-through current was imbalanced about 3:1
I changed to DIN rail mount 63A Schneider Multi-9 breakers and it matched within 10%.
Now I'm using Midnight/CBI 60A magnetic/hydraulic breakers, and it is matched within a couple percent.

There are some other brands and models with 200A relay. SolArk has that internal. Sunny Boy Storage uses external relay (and auto-transformer), but is only 6kW inverter. I think European model Sunny Island optionally uses 200A external relay, but that model isn't in the U.S. yet.

Easier to have multiple sub-panels, each supported by a single pass-through relay. Have to allocate loads appropriately.
I've toyed with the idea of doing that for my Sunny Islands. When off-grid, could parallel their outputs using a relay. They work fine off-grid, but I think I've had issues with over-current faults or tripping OCP during transition between on/off grid while carrying more current than a single relay can handle.

Another way to go, which I used earlier, is main panel feeds inverter feeds critical loads panel.
In a power failure, manually shut off breaker to inverter, and manually backfeed main panel through interlocked "generator" breaker.
On grid, big loads are powered through main breaker, not through inverter. Off-grid, all loads are connected to inverter; you have to manage them to avoid excess wattage or watt-hour load.