Powerwall discharging in Backup Only Mode

[Revrag]

My system was installed last week. (8.16KWh + Powerwall). Initially they charged the Powerwall from the grid to 100% but once the solar was installed they changed some setting so that it will only charge from Solar. That's good I guess except I can't turn my solar on until I get the interconnect agreement so can't charge my Powerwall.

The bigger problem is that even with settings set to Backup Only 100% my Powerwall is being used to power my home. It appears anytime my home usage is over 8kW the system pulls from the Powerwall to try and keep my grid usage at 8kW. Has anyone seen this before? With the rolling blackouts we're experiencing in California I'd like to be able to count on my Powerwall for backup but I turned the breaker off when it was drained below 50% (again while set to backup only).

Is there anyway to stop it from discharging to power my home, or allow it to charge from grid until my solar can be turned on?

 

[Revrag]

The other issue I'm having is the kW the Tesla app is reporting I'm pulling from the grid is way too high. When the app is reporting I'm pulling 8.2kW the meter only shows 6.3kW. Not sure if this is contributing to the Powerwall kicking in when it shouldn't be.

 

[miimura]

When it's sunny out, turn on the solar and turn off your main breaker. That will allow the Powerwalls to charge and you can't be dinged for running the solar before PTO because you're not connected to the grid. When they are almost full, turn off the solar and go back on the grid.

If the app is not showing reasonable numbers, the internal energy meter (Neurio) may not be configured correctly or the CTs may not be installed properly. If you have the new Gateway 2, it has a new energy meter built in, but is still susceptible to mis-configuration or mis-installation of the CT sensors.

 

[BrettS]

When it's sunny out, turn on the solar and turn off your main breaker. That will allow the Powerwalls to charge and you can't be dinged for running the solar before PTO because you're not connected to the grid. When they are almost full, turn off the solar and go back on the grid.

This will work, but it may be quite disruptive. The OP says that he only has one powerwall, so it’s likely that he doesn’t have a whole home backup. By turning off the service disconnect he will lose power for everything but his backed up loads.

The less disruptive way to do it would be to turn the solar on and stay attached to the grid, making sure that the powerwall is in backup only mode. In this case the system will prioritize charging the powerwall, so all of the solar power will go to the powerwall. However, you will need to keep a close eye on it because once the powerwall is full it will start feeding power back to the grid. Maybe just to be safe you’ll want to turn the solar back off once the powerwall gets to 90 or 95%.

 

[wjgjr]

This will work, but it may be quite disruptive. The OP says that he only has one powerwall, so it’s likely that he doesn’t have a whole home backup. By turning off the service disconnect he will lose power for everything but his backed up loads.

The less disruptive way to do it would be to turn the solar on and stay attached to the grid, making sure that the powerwall is in backup only mode. In this case the system will prioritize charging the powerwall, so all of the solar power will go to the powerwall. However, you will need to keep a close eye on it because once the powerwall is full it will start feeding power back to the grid. Maybe just to be safe you’ll want to turn the solar back off once the powerwall gets to 90 or 95%.

This is true, though it is fair to note that, depending on the wording of the agreements signed with the utility, this may be more likely to be seen as a violation of those terms, even if power is never actually exported. I am not sure it is any more likely to be noticed than operating entirely off grid.

 

[Vines]

OP do you have Gateway 2?

 

[Revrag]

OP do you have Gateway 2?

I'm not sure to be honest. How do I tell? It was just installed a week and a half ago so I'm assuming it's whatever the latest is.

Thanks for the suggestions I will definitely try something just not sure what yet. I do still have a couple of questions...
Has anyone else seen this behavior where the Powerwall kicks in (even in backup only mode) when it thinks usage from grid is over 8kW. Is this something that can be turned off?

Also, if I turn the system on just to charge the Powerwall and then back off again am I damaging the inverter? The instructions on the Tesla site say that once the inverter is on it should only be turned off for emergency or maintenance.

 

[Vines]

I'm not sure to be honest. How do I tell? It was just installed a week and a half ago so I'm assuming it's whatever the latest is.

Thanks for the suggestions I will definitely try something just not sure what yet. I do still have a couple of questions...
Has anyone else seen this behavior where the Powerwall kicks in (even in backup only mode) when it thinks usage from grid is over 8kW. Is this something that can be turned off?

Also, if I turn the system on just to charge the Powerwall and then back off again am I damaging the inverter? The instructions on the Tesla site say that once the inverter is on it should only be turned off for emergency or maintenance.

If there is a "Mini Powerwall" then you have Gateway 2.

 

[Revrag]

If there is a "Mini Powerwall" then you have Gateway 2.

Then yes, I have Gateway 2.

 

[Vines]

You should call your installer back out. It is possible they have some CT Meters or setting set incorrectly. Without seeing your whole electrical diagram and pictures of your panel I cant tell whats wrong from here. It is possible that what you see is exactly true, and if so some loads need to come off the essential panel and be not backed up. Alternatively if the non backup metered panel option is used then the settings or CT are incorrect.