Can anyone suggest an AIO hybrid Inverter that plays nice with Tesla powerwall 2?

I know Tesla is kind of their own walled garden but I was given two powerwall 2s from pge and now.im trying to figure out the rest of the components to get away from pge. I picked up 26 550w panels and now need a hybrid inverter.

EG4 18? Kind of expensive
Fronius 12.5? Seems pretty nice at $3300

Any other ones to consider?

Why can’t you just confirm that the PowerWall 2 can AC couple grid form for any 1741SA grid-tie inverter.

Once that is established you can buy anything including those 12kW growatts that cost $1500 and have full grid tie certification.

20-30kWh is not that much for a cord cutter unless you’re still keeping the grid connection for low production days.

And if you meant have a battery that plays with PW2…. Generally grid forming inverters need to be same brand and often same model to work correctly with each other without weird stuff/becoming a science fair project

zanydroid said:

Why can’t you just confirm that the PowerWall 2 can AC couple grid form for any 1741SA grid-tie inverter.

Once that is established you can buy anything including those 12kW growatts that cost $1500 and have full grid tie certification.

20-30kWh is not that much for a cord cutter unless you’re still keeping the grid connection for low production days.

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Yeah, I'll keep the grid for low days or if I surge in power.

I honestly don't know what ac couple grid from any 1741sa grid tie inverter means. I'll ask someone though.

ahreno said:

Yeah, I'll keep the grid for low days or if I surge in power.

I honestly don't know what ac couple grid from any 1741sa grid tie inverter means. I'll ask someone though.

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Search for it in the forum, it's a popular topic.

A MIN11400TL-XH-US is a bit undersized for your number of panels but it's a good starting point for discussion. It is $1500 and should be legal to use with PG&E. There's at least one fan of this inverter for this use case, on this forum.

UL1741SA = recent (~5 years) revision to the UL standard for inverter, that (for the purposes of this discussion) added various ways to throttle back output from grid tie inverters.

AC coupling grid form = Normally grid tie inverters will only turn on if they see the grid. Powerwalls (like couple other similar equipment) are capable of creating a fake grid that can convince grid tie inverters to turn on. And then they use the 1741SA control functions for power balancing.

Fortunately you either intentionally or accidentally picked a number of panels that the powerwalls can manage, they have a limit.

You probably don’t want a hybrid inverter or an AIO, those mean specific things that do not interact well with PowerWall.

AIO implies off grid despite the name.

Hybrid typically does grid forming.

Looks like you’ve gotten a ton of help before, I would recommend rolling up in the top message of a new thread a summary of the learnings and new info you want relative to the stuff you got from previous thread…

zanydroid said:

AIO implies off grid despite the name.

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AiO = All In One
AIO's are available in both off grid and hybrid versions.

zanydroid said:

You probably don’t want a hybrid inverter or an AIO, those mean specific things that do not interact well with PowerWall.

AIO implies off grid despite the name.

Hybrid typically does grid forming.

Looks like you’ve gotten a ton of help before, I would recommend rolling up in the top message of a new thread a summary of the learnings and new info you want relative to the stuff you got from previous thread…

Click to expand...

agreed. its hard because it seems everytime i think i have something figured out, someone else chimes in on how its wrong or whatever

zanydroid said:

Search for it in the forum, it's a popular topic.

A MIN11400TL-XH-US is a bit undersized for your number of panels but it's a good starting point for discussion. It is $1500 and should be legal to use with PG&E. There's at least one fan of this inverter for this use case, on this forum.

UL1741SA = recent (~5 years) revision to the UL standard for inverter, that (for the purposes of this discussion) added various ways to throttle back output from grid tie inverters.

AC coupling grid form = Normally grid tie inverters will only turn on if they see the grid. Powerwalls (like couple other similar equipment) are capable of creating a fake grid that can convince grid tie inverters to turn on. And then they use the 1741SA control functions for power balancing.

Fortunately you either intentionally or accidentally picked a number of panels that the powerwalls can manage, they have a limit.

Click to expand...

yeah, i was just talking to the installer of the batteries. and he said my array is too big

"The power wall 2 is limited to 5 kW of PV input, so for you, with two powerwall 2's, your maximum PV input is 10 kW. That PV system that you described won't always be producing at maximum, but during an outage at noon in the summer, your system will shut down the PV...and might injure your batteries."

would you worry about that? it seems a perfect storm (full perfect sun, power outage mid day, house not taking any draw from panels) would have to happen to have a concern? inverters can't throttle back the output?

Also, which way is that growatt undersized? the max output of 48amp seems on the low side, otherwise it can easily handle the PV array.

it turns out the panels are 408watt + up to 150w bifacial gain which is obviously unlikely.

I haven't installed the panels, so i could always just throw a couple in storage for when/if one dies in the future.

i was told i do need a hybrid inverter, which that growatt isn't. do i not need a hybrid because the powerwalls are ac and not dc?

ahreno said:

would you worry about that? it seems a perfect storm (full perfect sun, power outage mid day, house not taking any draw from panels) would have to happen to have a concern? inverters can't throttle back the output?

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This is correct. Inverters can throttle but across brands/without special engineering they need to be conservative.

As for worrying about it. Your permit will be rejected because it violates the install instructions on the powerwall.

A way around this is to have some of the grid tie solar bypass the powerwall and go straight to grid. These will not be active when running off grid. Only have 10kW into powerwall.

ahreno said:

Also, which way is that growatt undersized? the max output of 48amp seems on the low side, otherwise it can easily handle the PV array.

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Often people shoot for like 1.2x overpaneling of panels vs AC capacity, but this is just a rule of thumb.

With the 408*26 it is well matched, but you probably want a 10kW-AC string inverter.

ahreno said:

I haven't installed the panels, so i could always just throw a couple in storage for when/if one dies in the future.

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Yes banking a few is a good idea because you’ll have a hell of a time finding the same panel again in the future if one breaks and you want it to look good after a replacement

ahreno said:

i was told i do need a hybrid inverter, which that growatt isn't. do i not need a hybrid because the powerwalls are ac and not dc?

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The powerwalls form a grid, you only need one grid forming inverter.

As for why people told you, either they were objectively wrong or they answered the question for a different context than what you have. You’d have to link the responses to have someone referee it.