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Can't Charge Tesla Powerwall While Charging it with Solar?

I’m getting cost estimates for a home backup battery system from the company who installed our solar panels (not Tesla solar panels). The company I’m working with will install Tesla Powerwalls or Enlighten battery systems. I was surprised to learn that the Powerwall cannot be charged from our solar panels while it is being used for battery backup. It can only be charged from solar if we are not using the Powerwall or from the grid. But the Enlighten battery can be charged from solar while it’s being used for backup. The Powerwall limitation would likely not be an issue for backup battery use during a single day of power outage but could be a problem if the outage lasted multiple days.

I asked the rep if the Powerwall limitation was because we have Enlighten Inverters and Combiner for our solar power system and he said no, the limitation is in the Powerwall design itself. Also, in the event of a power outage, they recommend that a breaker be switched when converting to Powerwall backup use while the Enlighten system will do the switching automatically with no manual switching required.

These Powerwall limitations sounded odd to me. I assumed Powerwalls would be more technology advanced and easier to use than other batteries. Does anyone else have experience in comparing Powerwall usage during a power outrge versus other battery systems?
 

jjrandorin

Moderator, Model 3, Tesla Energy Forums
Moderator
Nov 28, 2018
14,589
18,663
Riverside Co. CA
I’m getting cost estimates for a home backup battery system from the company who installed our solar panels (not Tesla solar panels). The company I’m working with will install Tesla Powerwalls or Enlighten battery systems. I was surprised to learn that the Powerwall cannot be charged from our solar panels while it is being used for battery backup. It can only be charged from solar if we are not using the Powerwall or from the grid.

Thats not true. Perhaps that company doesnt know how to install them, or is specifically trying to shunt you away from them, but that statement is categorically false. There is no manual switching needed (it works automatically) and the powerwall can provide power to the home while being charged by solar.

Perhaps there is something specific about your setup that makes this not so, but I doubt it. those are both false statements (that powerwalls need to be switched manually and that you cant power your home and charge the powerwall from solar at the same time).
 
Thats not true. Perhaps that company doesnt know how to install them, or is specifically trying to shunt you away from them, but that statement is categorically false. There is no manual switching needed (it works automatically) and the powerwall can provide power to the home while being charged by solar.

Perhaps there is something specific about your setup that makes this not so, but I doubt it. those are both false statements (that powerwalls need to be switched manually and that you cant power your home and charge the powerwall from solar at the same time).
Thanks for the info. I suspect the rep I'm dealing with is not knowledgeable about Powerwalls and/or has an ulterior motive.

Do you know if the Powerwall can be charged by non Tesla solar power systems while the grid is out? Our solar power electronics is provided by Enlighten, not Tesla.
 

jjrandorin

Moderator, Model 3, Tesla Energy Forums
Moderator
Nov 28, 2018
14,589
18,663
Riverside Co. CA
Thanks for the info. I suspect the rep I'm dealing with is not knowledgeable about Powerwalls and/or has an ulterior motive.

Do you know if the Powerwall can be charged by non Tesla solar power systems while the grid is out? Our solar power electronics is provided by Enlighten, not Tesla.

Yes, its brand agnostic as far as solar goes. Powerwalls are AC coupled so can be connected to just about any PV inverter source. A lot of companies dont like to sell them because of the wait times to get them, or because third party installers pay the same price we do for the part themselves ( they dont get a discount in most cases, maybe they do if they buy in large volume?)

Them making those statements to you means they either were specifically misleading you (doubtful but possible) or just not informed / saying "what they were told to say" when someone talks about powerwalls.
 
Thanks for the info. I suspect the rep I'm dealing with is not knowledgeable about Powerwalls and/or has an ulterior motive.

Do you know if the Powerwall can be charged by non Tesla solar power systems while the grid is out? Our solar power electronics is provided by Enlighten, not Tesla.
My 66 solar panels are not Tesla panels, and they send power to my power walls without difficulty. The guy is a flake. I bought my panels from a solar panel dealer, not Tesla, and they do the same job as any other panels for half the cost. I installed them on my own roof with the help of my wife and my sister-in-law, so it's not rocket science. I did get a Tesla service guy out to put in the inverter and wire the batteries, and he did his job without having to sell me the panels.
 
I’ve been checking Tesla’s site for more information about how Powerwall works and found this page that describes how the associated Tesla Backup Switch works and when it can be used.
https://www.tesla.com/support/energy/powerwall/learn/tesla-backup-switch
It appears the Backup Switch is required to automatically switch house power to the Powerwall in the event of a power outage on the grid. The article says the Backup Switch cannot be used in partial backup systems, only whole home backup systems. It also states that the Tesla Backup Switch may not be approved by some utilities. Since my plan is to backup some of my home circuits but not all of them, this may explain why the rep I’m working with says a manual switch would be required to switch to backup power during an outage. Does anyone here have automatic switch-over to a Tesla Powerwall with partial home backup?
 
I’ve been checking Tesla’s site for more information about how Powerwall works and found this page that describes how the associated Tesla Backup Switch works and when it can be used.
https://www.tesla.com/support/energy/powerwall/learn/tesla-backup-switch
It appears the Backup Switch is required to automatically switch house power to the Powerwall in the event of a power outage on the grid. The article says the Backup Switch cannot be used in partial backup systems, only whole home backup systems. It also states that the Tesla Backup Switch may not be approved by some utilities. Since my plan is to backup some of my home circuits but not all of them, this may explain why the rep I’m working with says a manual switch would be required to switch to backup power during an outage. Does anyone here have automatic switch-over to a Tesla Powerwall with partial home backup?
That is what the Gateway 2, (which I have), is for. it will cut off the grid if it goes down and power the house with the PWs.
 

jjrandorin

Moderator, Model 3, Tesla Energy Forums
Moderator
Nov 28, 2018
14,589
18,663
Riverside Co. CA
I’ve been checking Tesla’s site for more information about how Powerwall works and found this page that describes how the associated Tesla Backup Switch works and when it can be used.
https://www.tesla.com/support/energy/powerwall/learn/tesla-backup-switch
It appears the Backup Switch is required to automatically switch house power to the Powerwall in the event of a power outage on the grid. The article says the Backup Switch cannot be used in partial backup systems, only whole home backup systems. It also states that the Tesla Backup Switch may not be approved by some utilities. Since my plan is to backup some of my home circuits but not all of them, this may explain why the rep I’m working with says a manual switch would be required to switch to backup power during an outage. Does anyone here have automatic switch-over to a Tesla Powerwall with partial home backup?

The "backup switch" you are talking about is not the tesla backup gateway. The backup gateway works automatically, full stop. The "backup switch" is a new product that tesla is trying to introduce to reduce complexity, but it has not fully passed certification in all areas yet.

I gave you the answer in the first response in this thread. There is no manual switch required (period).

EDIT:

The above may sound a bit "dry" or "rough", but I (and others in this thread) are telling you how it works as owners of the products. We are not guessing.
 
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The problem with one Powerwall and 44 panels is that the solar can and will generate more power than the Powerwall can accept. (3-5kW)

All the best,

BG
Yup, Around 11am I can see that it's maxing out charging at 5kw and the system is putting out around 8 to 9 and sending what I don't use to the grid.
I get a buyback of a little over .10/kWh. My draw from the grid is at .143/kWh.
Most days lately, I've been averaging around 35kWh net exported. One day I had 58.7kWh net exported.
 
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h2ofun

Active Member
Aug 11, 2020
3,700
891
auburn, ca
Yup, Around 11am I can see that it's maxing out charging at 5kw and the system is putting out around 8 to 9 and sending what I don't use to the grid.
I get a buyback of a little over .10/kWh. My draw from the grid is at .143/kWh.
Most days lately, I've been averaging around 35kWh net exported. One day I had 58.7kWh net exported.
I net exported about 115kwh the other day :)
 

miimura

Well-Known Member
Aug 21, 2013
7,314
7,293
Los Altos, CA
I’ve been checking Tesla’s site for more information about how Powerwall works and found this page that describes how the associated Tesla Backup Switch works and when it can be used.
https://www.tesla.com/support/energy/powerwall/learn/tesla-backup-switch
It appears the Backup Switch is required to automatically switch house power to the Powerwall in the event of a power outage on the grid. The article says the Backup Switch cannot be used in partial backup systems, only whole home backup systems. It also states that the Tesla Backup Switch may not be approved by some utilities. Since my plan is to backup some of my home circuits but not all of them, this may explain why the rep I’m working with says a manual switch would be required to switch to backup power during an outage. Does anyone here have automatic switch-over to a Tesla Powerwall with partial home backup?
Look at the page linked below. It covers the different configurations that use either the Backup Switch (behind the meter) and the Backup Gateway (separate box).


The reason that the Backup Switch must be whole home backup is that it is interrupting the grid at the meter. The Backup Gateway can interrupt the grid at various different places in your home wiring so that it can provide whole home, almost whole home, and partial home backup depending on the total system design.
 
Look at the page linked below. It covers the different configurations that use either the Backup Switch (behind the meter) and the Backup Gateway (separate box).


The reason that the Backup Switch must be whole home backup is that it is interrupting the grid at the meter. The Backup Gateway can interrupt the grid at various different places in your home wiring so that it can provide whole home, almost whole home, and partial home backup depending on the total system design.
That is very helpful, thank you.
 

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