Welcome to Tesla Motors Club
Discuss Tesla's Model S, Model 3, Model X, Model Y, Cybertruck, Roadster and More.
Register

Can I have 1 powerwall with a 11.4kW PV system?

jjrandorin

Moderator, Model 3, Tesla Energy Forums
Nov 28, 2018
9,500
10,683
Riverside Co. CA
But having 2 power walls with a single 7 or 7.6kW inverter shouldn’t have been a problem, but the OP of that thread said that their power still went out even when they only had a single inverter on.
That would depend on what the max generation for that 7.6 inverter is. Most people assume that it wont generate that much because all the panels dont point one way, etc. If their 7.6 inverter is hooked up to enough panels to produce >5kW continuous (which I believe it is, as I believe they have a ground mounted array), its the same issue.

PV generation >5kW continuous per powerwall is the issue. Its entirely possible for someone to have a 7.6kW inverter that never peaks above 5kW continuous for any appreciable amount of time.. that would be normal for a roof mounted system. It would be pretty unusual for a 11.4kW sized system to never generate more than 5kW continuous, though (the OP in this thread).
 

Zinc_Saucier

Member
Jul 30, 2020
46
27
Massachusetts
That would depend on what the max generation for that 7.6 inverter is. Most people assume that it wont generate that much because all the panels dont point one way, etc. If their 7.6 inverter is hooked up to enough panels to produce >5kW continuous (which I believe it is, as I believe they have a ground mounted array), its the same issue.

PV generation >5kW continuous per powerwall is the issue. Its entirely possible for someone to have a 7.6kW inverter that never peaks above 5kW continuous for any appreciable amount of time.. that would be normal for a roof mounted system. It would be pretty unusual for a 11.4kW sized system to never generate more than 5kW continuous, though (the OP in this thread).
The max generation for a 7.6kW inverter isn’t going to be above 10kW, which is why I’m saying that something else must have been going on as well in the thread you linked if that OP’s power shut off when only using one of their inverters and 2 PWs.

I 100% agree with your second paragraph and am in agreement that 2+ PWs would be required for 11+ kW inverters.
 

jjrandorin

Moderator, Model 3, Tesla Energy Forums
Nov 28, 2018
9,500
10,683
Riverside Co. CA
The max generation for a 7.6kW inverter isn’t going to be above 10kW, which is why I’m saying that something else must have been going on as well in the thread you linked if that OP’s power shut off when only using one of their inverters and 2 PWs.

I 100% agree with your second paragraph and am in agreement that 2+ PWs would be required for 11+ kW inverters.

Thats a good point, I just remember that specific thread for the issue. Maybe tag the OP of that thread for more info on it.
 

Zinc_Saucier

Member
Jul 30, 2020
46
27
Massachusetts
@zƬesla did you ever get a root cause as to why your power was dropping out when only running on one inverter and 2 PWs in the below thread? Or did no one dive into the root cause as adding a third PW solved the symptoms?

This thread has a TMC members experience with this. It was not 1 powerwall, but the situation was the exact same ("not enough powerwalls for amount of PV").

 

charlesj

Active Member
Oct 22, 2019
1,181
251
Monterey, CA
Read through the thread I linked in post #6, for someone who had more PV than their powerwalls could take in.
From his post 1
" the PWs keep shutting the inverters off. Even with just one inverter on and PWs mostly charged, we sometimes see the whole house lose power (clocks reset/etc) for a several seconds"
Power lost for a few seconds, not completely even though the app showed no power flow. Not sure what to make of that as he didn't say house power down until grid was back on.
 

zƬesla

Member
Apr 16, 2020
378
119
US-NH
@zƬesla did you ever get a root cause as to why your power was dropping out when only running on one inverter and 2 PWs in the below thread? Or did no one dive into the root cause as adding a third PW solved the symptoms?
No definitive answer. As the installer owned up to mis-designing our system and put in the third PW at no cost to us, we didn't push for an answer. Haven't seen the issue pop up again with the third PW, although there have only been a couple of outages since.
 

About Us

Formed in 2006, Tesla Motors Club (TMC) was the first independent online Tesla community. Today it remains the largest and most dynamic community of Tesla enthusiasts. Learn more.

Do you value your experience at TMC? Consider becoming a Supporting Member of Tesla Motors Club. As a thank you for your contribution, you'll get nearly no ads in the Community and Groups sections. Additional perks are available depending on the level of contribution. Please visit the Account Upgrades page for more details.


SUPPORT TMC
Top