Tesla Powerwall

[HoosierSparky]

Solar City is making a big push on these since the buyout by Tesla. In reading the specs, the operating temp tops out at 122F (50C). In the southwest desert areas, installing these in a garage or west facing wall would provide temps in excess of this limit.

If the specs state the temp limits, should these be installed where the ambient temp will exceed the limit for 20-30% of the year?

 

[JFletcher]

Solar City is making a big push on these since the buyout by Tesla. In reading the specs, the operating temp tops out at 122F (50C). In the southwest desert areas, installing these in a garage or west facing wall would provide temps in excess of this limit.

If the specs state the temp limits, should these be installed where the ambient temp will exceed the limit for 20-30% of the year?

Not sure about Scottsdale, but the record high for Phoenix was 122*F:

"On June 20, 1990, the temperature reached an all-time recorded high of 122 °F (50 °C)." (wiki)

How much hotter are you anticipating?

 

[gadfly56]

Not sure about Scottsdale, but the record high for Phoenix was 122*F:

"On June 20, 1990, the temperature reached an all-time recorded high of 122 °F (50 °C)." (wiki)

How much hotter are you anticipating?

An uninsulated west-facing garage wall could easily see temps up to 140F in that area.

 

[jaggedben]

...

If the specs state the temp limits, should these be installed where the ambient temp will exceed the limit for 20-30% of the year?

Well... No.

Install it in the shade?

 

[gadfly56]

Well... No.

Install it in the shade?

Add a couple extra PowerWalls to account for the A/C needed to cool the installation area.

 

[Fulthrotl]

An uninsulated west-facing garage wall could easily see temps up to 140F in that area.

but it's a *dry* heat.......

except during monsoon season,
which is six weeks of broccoli steamer simulation.

 

[HoosierSparky]

Not sure about Scottsdale, but the record high for Phoenix was 122*F:

"On June 20, 1990, the temperature reached an all-time recorded high of 122 °F (50 °C)." (wiki)

How much hotter are you anticipating?

Published temperatures in the Phoenix area are taken in the shade. I've been in the area since 1977. Since then I have experienced 122 and 123 a few times. I had worked on "soft start" units for overhead cranes here that were had a design peak of 60C. Lots of electronic failures. The units were installed on the cranes running under a metal roof in an open building. I ended up removing them.

 

[ggunn]

Tesla has had (and maybe still is having) delivery problems with the AC PowerWall 2, which is the only model still orderable.

 

[HoosierSparky]

Tesla has had (and maybe still is having) delivery problems with the AC PowerWall 2, which is the only model still orderable.

Nice marketing by Tesla. AC Powerwall. IT'S A BATTERY!! The built in converter/inverter provides the AC. It STORES DC.

 

[Chamuit]

I called down to Phoenix once and asked what the design ambient temp was for them. Guy said, 104F.

 

[Besoeker]

Well... No.

Install it in the shade?

Very good.........

 

[gadfly56]

I called down to Phoenix once and asked what the design ambient temp was for them. Guy said, 104F.

Is that per ASHRAE, and is it the 97% or 99% design?

 

[Fulthrotl]

Nice marketing by Tesla. AC Powerwall. IT'S A BATTERY!!
The built in converter/inverter provides the AC. It STORES DC.

last time i checked, batteries don't store AC worth a damn.

 

[jaggedben]

All kidding aside, Powerwall is not merely a battery.

 

[wwhitney]

Speaking of Tesla Powerwall 2 AC, the website says that it supports both solar and grid backup. I assume that means it supports islanding with solar, so does anyone know what mechanisms it supports for reducing solar output when the batteries are full and production exceeds demand? Probably just phase shifting, but it would be nice if it supported a dump load.

Cheers, Wayne

 

[GoldDigger]

Speaking of Tesla Powerwall 2 AC, the website says that it supports both solar and grid backup. I assume that means it supports islanding with solar, so does anyone know what mechanisms it supports for reducing solar output when the batteries are full and production exceeds demand? Probably just phase shifting, but it would be nice if it supported a dump load.

Cheers, Wayne

If it is DC coupled (panels feeding to a charge controller which is part of the PowerWall/Storedge package and not to a GTI), then no "mechanism" is needed and the battery charger/inverter driver simply pulls less current from the panel array, as needed.
Using a high voltage battery pack would let you get perfectly good efficiency with a battery/charger driving a grid interactive inverter with standalone operation.

The need for PV output control comes in when the system is AC coupled with a pure GTI connected via a transfer switch to grid direct or to standalone inverter/charger.

 

[jaggedben]

It is AC coupled.

 

[wwhitney]

If it is DC coupled

To my knowledge, Tesla Powerwall 2 AC is AC-coupled. If you want a DC coupled system with a Storedge Inverter, you get the Tesla Powerwall 2 DC.

In any event, my interest is in the AC coupled case.

Cheers, Wayne

 

[gadfly56]

To my knowledge, Tesla Powerwall 2 AC is AC-coupled. If you want a DC coupled system with a Storedge Inverter, you get the Tesla Powerwall 2 DC.

In any event, my interest is in the AC coupled case.

Cheers, Wayne

Which, as I understand it, is not being manufactured and there are no plans to go forward with it. See this amusing article from down under. Also, looks like the inverter won't support off-grid solutions as there is no way to match charging current to demand when the demand is less than 100%. At least, that's how I read it.

 

[jaggedben]

Tesla's solution would support off grid systems, albeit perhaps not optimally. To work decently well, the solar system just can't be too large per Powerwall.
An advantage of their design is that it does not matter what type of solar a homeowner already has or wants.