Powerwall 3 Roadmap - 3 Phase Coming!

[TJYokel]

Hi All,

Firstly, I apologize in advance for dragging up a thread from 6 weeks ago, but i was hoping that one of you would have a better understanding of how the PW3's inverter would work in the situation below (and yes i expect the info is probably still very unclear from Tesla at this stage).

If i had a PW3 with 20Kw of panels during the peak period of the day and the PW3 was charging @ 5Kw (which i think is the maximum charging rate?) and my house was using 3Kw, would the Export to the grid still be the maximum rate of 11.5 Kw?

Or is the 11.5KW Inverter limit the total of all 3 (Grid, House and Charging)thus meaning my Grid feed in the scenario above would only be 2.5Kw ?

Also if i add my Tesla MYLR into the mix and it is charging @11kw i'm assuming my Feed into the grid would be 0 during this time (well .5Kw but that would be negligible)

Thanks for your help and please use lots of crayons and small words for us uninformed....

 

[MP3Mike]

PW3 was charging @ 5Kw (which i think is the maximum charging rate?)

I think that charging limit is only when charging from AC, not solar.

Or is the 11.5KW Inverter limit the total of all 3

I think 11.5kW is the limit of how much AC can be generated from solar. But the charging may be on top of that being direct DC charging from solar.

 

[cafz]

If i had a PW3 with 20Kw of panels during the peak period of the day and the PW3 was charging @ 5Kw (which i think is the maximum charging rate?) and my house was using 3Kw, would the Export to the grid still be the maximum rate of 11.5 Kw?

Or is the 11.5KW Inverter limit the total of all 3 (Grid, House and Charging)thus meaning my Grid feed in the scenario above would only be 2.5Kw ?

The inverter is the part that converts DC to AC, so it would make sense for the inverter limit to apply to the total amount of AC generated, which would be house + export but not including charging (so in your example, 3kW house load + 8.5kW export).

 

[Vostok]

i was hoping that one of you would have a better understanding of how the PW3's inverter would work in the situation below

As @cafz mentioned, the inverter is the limiting factor as it converts the solar DC to AC for use everywhere else, including exporting and charging the battery. Almost all PW2 are AC coupled not DC coupled. IIRC, DC coupled PW2 were never sold in Australia but I could be wrong.

If PW3 with an integrated 11.5 kW inverter actually DC couples the battery (because it can) then that might mean you have 11.5 kW to run the house and export, and battery charging is not part of that limit.

The specs for US PW3 say it can AC discharge at 11.5 kW (i.e. the inverter’s limit) but peak charge rate is still 5 kW. That implies the maximum power flow at any instant of time is 16.5 kW, and your solar will be capped if/when it hits that number.

In most cases that shouldn’t be much of an issue since few solar arrays are so perfectly oriented / not overshadowed such that they output their peak nameplate power for any significant length of time. A rule of thumb I’ve seen is inverters are typically dimensioned to 75% the solar nameplate.

Taking out 5 kW DC charging of the battery, you’re left with 15 kW of solar, and 75% of that is 11.25 kW, i.e. just under the 11.5 kW inverter limit. So it all seems to add up.

 

[JonDarian]

I can't say what the PW2 can do, but will offer a PW2 data point. I have 20kW of panels and a 15kW inverter, along with a PW2. Because I live in the tropics, it is quite common for my system to have filled the battery and be exporting close to 15kW for a few hours in the middle of the day (the inverter limit, minus the household consumption). This is through the hotter months. Depending on where you live, it may not be reasonable to assume that you will be using 5kW of your peak production to fill your battery, as it may already be full by the time the peak arrives.

 

[MP3Mike]

but peak charge rate is still 5 kW.

Is that true even for DC charging? The specs only mention the limit for AC charging:

 

[Vostok]

Is that true even for DC charging? The specs only mention the limit for AC charging:

View attachment 1049528

If the specs don’t say, then we don’t know. I was making an assumption on the basis of the information we do have. So a clarification from Tesla would be nice…

 

[TJYokel]

Taking out 5 kW DC charging of the battery, you’re left with 15 kW of solar, and 75% of that is 11.25 kW, i.e. just under the 11.5 kW inverter limit. So it all seems to add up.

Thanks for the Clarification, and yes there is still a lot of unknowns but hopefully these will be cleared up before i'm ready to upgrade my system at home.

Right now i have 12Kw of panels into a 10Kw inverter on a Curved roof that i'm looking to expand to 20kw. Given the expansion i know i'm up for a new inverter so i either will just get a standalone inverter, extra panels and 1-2 PW2's or Panels and 1-2 PW3's (or 1 PW3 with an expansion pack)

This all really depends on PW3's ability to support 3 phase becoming a reality and not a glitch in the "Elon Reality Matrix"

We already have 1 Tesla and the wife is applying pressure to replace the 2nd car soon for another one so we will probably end up with 2 Wall chargers to accommodate.


Once thanks to everyone for chiming in and offering support

 

[technerdx6000]

Powerwall 3 is now available in the UK. Their grid is pretty similar to ours right? Hopefully that means an Australian release isn't far away

https://twitter.com/x/status/1802952037337800827

 

[B3AU]

Powerwall 3 is now available in the UK. Their grid is pretty similar to ours right? Hopefully that means an Australian release isn't far away

https://twitter.com/x/status/1802952037337800827

The Powerwall 3 released in the UK and Germany are single phase only.

https://twitter.com/x/status/1803251385288593831

 

[louco73]

I doubt they are going to release the Powerwall 3 in Australia with 3 phase support at launch. The roadmap slide indicated "future". I'm hoping for Q4, but it could be H1 next year.

Is anyone aware of what government entity has to certify/approve battery storage for the Australian market? Perhaps there is some public documentation repository to keep an eye on?

 

[technerdx6000]

My personal hunch is the "update" that provides 3 phase support is just a gateway firmware update. It will require 3 Powerwall 3s, each with a single phase inverter in them. The gateway firmware update allows the 3 powerwalls to operate synchronously with 120° phase separation.

I just don't see them putting in 3 phase inverters now and being able to update down the track.

 

[michalf]

My personal hunch is the "update" that provides 3 phase support is just a gateway firmware update. It will require 3 Powerwall 3s, each with a single phase inverter in them. The gateway firmware update allows the 3 powerwalls to operate synchronously with 120° phase separation.

I suspect this is exactly what will happen. But it would also mean that getting 3-phase support would cost you 3x price of a single PW3. I believe there would be some more cost-efficient ways to achieve it, even going with hybrid PV inverters and separate battery packs.

 

[louco73]

More information on the specifications and installation process, but nothing about 3 phase.

Note the comment about the new model coming to add additional Powerwall 3s that will not have the inverter. It's a bit tricky to know what to do, if you want to purchase it ASAP and wait for 3 phase after.

 

[technerdx6000]

But it would also mean that getting 3-phase support would cost you 3x price of a single PW3

Typically 3 phase use cases involve greater energy consumption requiring greater storage capacity. So a setup like that does make sense

 

[Vostok]

Note the comment about the new model coming to add additional Powerwall 3s that will not have the inverter.

Very interesting video. So it seems either an inverterless PW3 or inverterful PW3 could be used to replace an existing PW2 where someone already has an external inverter. The latter requiring AC coupling.

But in that situation, would you in fact be better off removing your external inverter, and DC coupling? Would that be more efficient? (smaller losses?)

I’m wondering, mainly because I reckon I’m on track for my PW2 to hit the warranty replacement threshold next year, and if PW2 are no longer in production by then, Tesla would have to replace it with a PW3. But of course, I already have an inverter. Also, I have the original Gateway 1 (grey box) and it, too, might need to be replaced. The video indicates PW3 still requires an external Gateway, but they didn’t say anything further about that.

I guess the options are:

1. Tesla replaces the existing PW2 with a new or refurbished PW2. End of story; or
2. Tesla replaces the existing PW2 with a new inverterless PW3 or AC-coupled inverterful PW3, and:
   1. Gateway 1 is kept in place if it can work with PW3; or
   2. Gateway 1 does not work with PW3 and it has to be replaced with Gateway 3.

 

[RichardV]

Very interesting video. So it seems either an inverterless PW3 or inverterful PW3 could be used to replace an existing PW2 where someone already has an external inverter. The latter requiring AC coupling.

I doubt a powerwall 3 could be DC coupled with a non Tesla inverter. The inverter would need to speak the same protocol as the battery.

I guess the options are:

1. Tesla replaces the existing PW2 with a new or refurbished PW2. End of story; or
2. Tesla replaces the existing PW2 with a new inverterless PW3 or AC-coupled inverterful PW3, and:
   1. Gateway 1 is kept in place if it can work with PW3; or
   2. Gateway 1 does not work with PW3 and it has to be replaced with Gateway 3.

I would of assumed that an inverterless PW3 is only stackable with an inverter PW3. So you can expand the battery capacity of a system without the expensive of a potentially unnecessary second inverter, unless you actually need more than 11kW inverter capacity.

 

[technerdx6000]

I would of assumed that an inverterless PW3 is only stackable with an inverter PW3

Yeah, this exactly. PW3 is only compatible with other inverters when AC coupled.

@Vostok I wouldn't be surprised if Tesla has a stash of refurbished PW2 hiding somewhere specifically for warranty cases. Especially since we're still well within the warranty period for all PW2 ever sold

 

[Vostok]

I doubt a powerwall 3 could be DC coupled with a non Tesla inverter. The inverter would need to speak the same protocol as the battery.

So in that case, you’d simply rip out the PW2 and existing inverter, and DC couple your solar array to the PW3?

 

[technerdx6000]

So in that case, you’d simply rip out the PW2 and existing inverter, and DC couple your solar array to the PW3?

Yes, exactly this. Probably need a gateway upgrade to a Backup Gate 2 too though