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Powerwalls inside or out for longevity?

Vines

Active Member
Jul 20, 2018
1,952
2,292
Silicon Valley, CA
Same here in MD - no code issues here with locating them in the utility room.

Many jurisdictions are still fine with them in utility spaces, coming next year there will be a 40 kWh rating maximum, so only 2 Powerwalls can go in interior locations, except the garage, which will have an 80 kWh limit just like outdoor locations, 80 kWh maximum.

If you want it in an interior space, I recommend permitting it before the codes change. All of California is getting an update to the ESS codes between January 1 and July 1, and these new maximums will be in force.
 

bayareaever

Member
Jun 17, 2013
389
235
East Bay Area
Many jurisdictions are still fine with them in utility spaces, coming next year there will be a 40 kWh rating maximum, so only 2 Powerwalls can go in interior locations, except the garage, which will have an 80 kWh limit just like outdoor locations, 80 kWh maximum.

If you want it in an interior space, I recommend permitting it before the codes change. All of California is getting an update to the ESS codes between January 1 and July 1, and these new maximums will be in force.[/

What about 3 PWs in an enclosed furnace room (in basement)? My install is probably around June so hopefully no issues with code.
 

Laketime

Member
Dec 13, 2020
151
101
LI NY
When it comes to what is acceptable I think we all need to realize the great disparity each state/municipality imposes. Some let you stack walls on top of each other, others insist you have a 36" space between them. Localities can be funny little cults that follow their own illogical methodology.

As far as the question of indoors vs outdoors- indoors is preferable for every thing in life, powerwalls included. Elements, insects, sun and temperature all want to eat away at those PWs. Inside they will preform better and last longer, just like a garaged car will do better than one stuck in the elements. If you can't do indoors then so be it, nothing in life is perfect...
 

sorka

Well-Known Member
Feb 28, 2015
8,174
5,949
Merced, CA
What's the difference between a utility space and a living space? Permitted living space or just any area that isn't heat/cooled? Or would it most often be a basement that isn't permitted as living space but isn't a garage either? The interior room on the other side of my PWs is a utility room we use for storage but it does have an HVAC vent.

I've made up my mind that I need to move them before the heat of the summer. At this point, it'll be the garage which doesn't get above 85F in the heat of the summer. I'll mean running 20 feet of conduit or so to get the 10 feet on the other side of the breezeway between the house and the garage.

Alternatively I'd consider some sort of venting system that allowed me to bring cooled air from inside.
 

sorka

Well-Known Member
Feb 28, 2015
8,174
5,949
Merced, CA
I talked about this extensively with my installer as I can either put them on a north facing exterior wall or an interior garage wall (though the interior wall would require some work to relocate built-in shelving and some other minor inconvenience).

In the end, with their reassurance, I decided theyll be fine and will put them outside on the North wall.

They gave me a quote of $3300 to move them. Too much for me to spend to try and safeguard their product from the environment so I'll either need to move them myself or keep them where they are.

Has anyone's powerwalls operated in 105+ temps and able to discharge at least 3KW per powerwall after being in these temps for hours? I have 3 powerwalls and plan to run 1 AC in the summer in the afternoon and evening for hours. Each AC takes runs at about 7KW and I have about a 1KW continuous baseline power draw during the day.
 

cobra

Member
Feb 8, 2021
158
29
Lansdale, PA, USA
I have the reverse question... if mounting powerwalls in any enclosed space, how much heat do they generate that would add to any conditioning requirements in the space?

For example, we have an unconditioned garage. It would often be more temperate than outdoors, but if we mounted 4 powerwalls and they give off heat, the space could be hotter than outdoors in summer, depending on their heat generation.
 

BGbreeder

Member
Jun 19, 2020
298
190
Bay Area
I have the reverse question... if mounting powerwalls in any enclosed space, how much heat do they generate that would add to any conditioning requirements in the space?

For example, we have an unconditioned garage. It would often be more temperate than outdoors, but if we mounted 4 powerwalls and they give off heat, the space could be hotter than outdoors in summer, depending on their heat generation.
You have to figure that the round trip losses (~10%) turn into heat, so you can guesstimate the added heat.

You can get an attic or gable fan and hook it up to a solar water heater controller to turn on whenever the garage is warmer than the outside. They use two temperature measuring probes, one inside and one outside.

All the best,

BG
 
Last edited:

sorka

Well-Known Member
Feb 28, 2015
8,174
5,949
Merced, CA
You have to figure that the round trip losses (~10%) turn into heat, so you can guesstimate the added heat.

You can get an attic or gable fan and hook it up to a solar water heater controller to turn on whenever the garage is warmer than the outside. They use two temperature measuring probes, one inside an one outside.

All the best,

BG

This is my efficiency for the first 4 months so far:

Screen Shot 2021-04-01 at 12.05.00 PM.png



I'll be interesting to see how much it drops during the summer heat.
 

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