Discussion: "Powerwall +"

[wjgjr]

We've got a full spec sheet!

Functionality will be more important in the end, but it looks nice and clean with fewer boxes.

Mildly interesting note is that the "battery assembly" is listed as 131 kg /289 lbs (and seems to exclude the wall bracket.) The PW2 specs list it as 114 ky / 251 lbs. That is a big weight increase with no listed increase in battery storage.

 

[MP3Mike]

It doesn't specifically say whole home backup... So I wonder if it will only backup specific loads, and you have to install a full blown Gateway if you want whole home backup.

 

[holeydonut]

Wow that’s a lot of max continuous output when off grid.

 

[h2ofun]

Looks like need 40 amp breaker? Totally different product that PW2

 

[aesculus]

It's not DC to DC, powerwall remains the same with integrated inverter

If this is true they missed a big opportunity IMHO. If they are accepting DC solar into the PW why do DC-AC-DC conversion?

 

[jjrandorin]

(moderator note: going to go ahead and sticky this thread, since I am virtually certain it will be an active thread for quite some time, and of interest to many who visit this section)

 

[dareed1]

Looks like need 40 amp breaker? Totally different product that PW2

Maybe I'm misreading the spec, but it looks to me like the BESS still is limited to 5kW discharge and 24A. The larger rating is for PV + BESS. Not sure that anything is different in the PW section.

 

[wjgjr]

Looks like need 40 amp breaker? Totally different product that PW2

It seems (with more info needed) that the piece called the "solar assembly" - the top box - may be needed to unlock the new discharge capacity limits. What is not clear is whether the battery is any different from the current PW2 (other than being heavier.)

 

[wwhitney]

The photo appears to show an electric meter adapter, which I assume would be a grid disconnect device (Microgrid Interconnect Device). Note that the meter shows two locking rings, one would be to lock the adapter to the all-in-one-panel, and one would be to lock the meter to the adapter. Plus there is the small flex conduit going from the top component of the Powerwall+ to the meter adapter.

So that would clarify the tweet about not having to change out main panels anymore. There's still the question of complying with the 120% rule, as the Powerwall+ appears to just be connected into the main panel. I suppose it is possible that they have CTs on the service conductors (edit: or are reading information from the smart meter) and can list the whole thing as a Power Control System so that the current going to the loads does not exceed the bus rating (or perhaps 120% of the bus rating).

Cheers, Wayne

 

[MP3Mike]

The photo appears to show an electric meter adapter, which I assume would be a grid disconnect device (Microgrid Interconnect Device). Note that the meter shows two locking rings, one would be to lock the adapter to the all-in-one-panel, and one would be to lock the meter to the adapter. Plus there is the small flex conduit going from the top component of the Powerwall+ to the meter adapter.

Good catch, I missed that.

 

[holeydonut]

The photo appears to show an electric meter adapter, which I assume would be a grid disconnect device (Microgrid Interconnect Device). Note that the meter shows two locking rings, one would be to lock the adapter to the all-in-one-panel, and one would be to lock the meter to the adapter. Plus there is the small flex conduit going from the top component of the Powerwall+ to the meter adapter.

So that would clarify the tweet about not having to change out main panels anymore. There's still the question of complying with the 120% rule, as the Powerwall+ appears to just be connected into the main panel. I suppose it is possible that they have CTs on the service conductors (edit: or are reading information from the smart meter) and can list the whole thing as a Power Control System so that the current going to the loads does not exceed the bus rating (or perhaps 120% of the bus rating).

Cheers, Wayne

This sucks for anyone who has their MSP within 36" of their gas riser then. I don't think PG&E or the AHJ will allow these extra things or conduit to be added.

Anyone who buys a home with underground service... but a really close gas riser... just can't catch a break when it comes to adding ESS.

 

[mongo]

The photo appears to show an electric meter adapter, which I assume would be a grid disconnect device (Microgrid Interconnect Device). Note that the meter shows two locking rings, one would be to lock the adapter to the all-in-one-panel, and one would be to lock the meter to the adapter. Plus there is the small flex conduit going from the top component of the Powerwall+ to the meter adapter.

So that would clarify the tweet about not having to change out main panels anymore. There's still the question of complying with the 120% rule, as the Powerwall+ appears to just be connected into the main panel. I suppose it is possible that they have CTs on the service conductors (edit: or are reading information from the smart meter) and can list the whole thing as a Power Control System so that the current going to the loads does not exceed the bus rating (or perhaps 120% of the bus rating).

Cheers, Wayne

What if, instead of discrete CTs, the meter interface adapter also includes current sense so SW prevents panel overload? That would also help with the creation of non-export energy systems which may reduce PoC restrictions.

 

[wwhitney]

What if, instead of discrete CTs, the meter interface adapter also includes current sense so SW prevents panel overload?

Yes, that would be another way to get the service conductor current, as I mentioned. If Tesla can rely on getting the information that way, it could eliminate the need for field installed CTs, other than the case of existing PV that does not go through the integrated PV inverter.

Another thought on protecting the busbar on the main panel: note the combined inverter export current is limited to 32A while on grid. That means if the main panel is a 200A panel, interconnection qualifies under the 120% rule.

Oh, and I checked the PCS rules in 2020 NEC 705.13, if that is the method to protect the main panel bus, the total bus current is limited to the bus rating.

Cheers, Wayne

 

[pdx_m3s]

So does this eliminate the need for a gateway, with PV going directly into the PW, and this PW/PV-inverter combo sitting between the meter and the main panel?

I'm trying to understand how this is "dramatically simpler" according to Mr. Musk.

 

[Southpasfan]

As long as we are guessing, I think what will make the installations more simple is all back up all the time. Plus, all Gateway. We will see.

 

[miimura]

The spec sheet posted above has a bunch of UL approval numbers. Do we know if this Powerwall + has the new UL certification that allows less restrictive installation according to the upcoming Cal Fire code? @Vines ???

 

[wwhitney]

So does this eliminate the need for a gateway, with PV going directly into the PW, and this PW/PV-inverter combo sitting between the meter and the main panel?

I'm trying to understand how this is "dramatically simpler" according to Mr. Musk.

No additional Gateway would be required, the meter adapter Microgrid Interconnect Device takes care of grid isolation. It is the only part that sits between the meter and the panel, that small flex conduit is too small for power conductors, I think, so it must be data/control only.

The inverters would be connected to a 50A breaker in the main panel, most likely at the opposite end of the bus from the grid connection. It's not clear to me from the spec sheet what size the PV inverter is, i.e. how much PV you can connect to one Powerwall+.

The less integrated simplest way they may be doing what the spec sheet says is that the bottom is just a normal Powerwall (except with some change, given the weight difference), and the top is the PV inverter and system controller, as they call it. The PV power would be inverted to AC, and that AC power could go to the panel/grid, to the PWs, or both.

The more integrated way would be to have a single inverter. That could possibly charge the batteries without the DC-AC-DC roundtrip losses. That would also suggest that the PV inverter could be rated 9.6 kW (and while inverting 9.6 kW from the PV, it could not export any power from the batteries).

Cheers, Wayne

 

[holeydonut]

No additional Gateway would be required, the meter adapter Microgrid Interconnect Device takes care of grid isolation. It is the only part that sits between the meter and the panel, that small flex conduit is too small for power conductors, I think, so it must be data/control only.

The inverters would be connected to a 50A breaker in the main panel, most likely at the opposite end of the bus from the grid connection. It's not clear to me from the spec sheet what size the PV inverter is, i.e. how much PV you can connect to one Powerwall+.

The less integrated simplest way they may be doing what the spec sheet says is that the bottom is just a normal Powerwall (except with some change, given the weight difference), and the top is the PV inverter and system controller, as they call it. The PV power would be inverted to AC, and that AC power could go to the panel/grid, to the PWs, or both.

The more integrated way would be to have a single inverter. That could possibly charge the batteries without the DC-AC-DC roundtrip losses. That would also suggest that the PV inverter could be rated 9.6 kW (and while inverting 9.6 kW from the PV, it could not export any power from the batteries).

Cheers, Wayne

So for every one of these Powerwall+ units in a home, it'll need a 50A breaker on the main panel? Or is this Powerwall+ an elegant solution for only one single battery and (maybe) a 9.6 kWp AC solar system?

 

[MP3Mike]

I wonder if you can have more than one Powerwall with this setup. And if so would it increase the power capability or only the total stored energy?

 

[wwhitney]

So for every one of these Powerwall+ units in a home, it'll need a 50A breaker on the main panel? Or is this Powerwall+ an elegant solution for only one single battery and (maybe) a 9.6 kWp AC solar system?

Unknown, the spec sheet does not say anything about how integrating multiple Powerwalls will be handled.

Cheers, Wayne