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Tesla Powerwall iPhone application - where does it take its measurements?

Tesla Powerwall iPhone application - where does it take its measurements?

I have a single Powerwall installed at my house and its been working great for the last year plus with my SolarCity solar panels.
I recently had a 2nd set of non-Tesla solar panels added to the roof of my house to increase the amount of solar energy that I was generating. To make things simple from an installation and troubleshooting standpoint, I had the power for these additional panels wired into my main power panel.
Since I use the Tesla Powerwall iPhone application to monitor my energy use as well as determine how charged my Powerwall is at any one time, I am confused now on what the Tesla Powerwall application's Power Flow diagram means given that I have another source of power coming into the main power panel from the 2nd set of non-Tesla solar panels. I think that what the application shows for how charged the Tesla Powerwall is and how much solar energy has come in from the Solar City solar panels is indeed correct but I wonder if the power coming from the 2d solar panels into the main power panel would should up in the Power Flow diagram as coming from the grid? Any ideas would be welcome.
Also, with the additional power to the main power panel from the 2nd set of solar panels, I wonder whether or not the Powerwall would correctly detect a loss of power from the grid on a hot day that all the solar panels are generating power but there is a power outage in the grid. Does the Tesla Powerwall determine a power outage from the lack of any power at the main power panel or can it detect the fact that the PG+E power at the grid is no longer there while the 2nd set of solar panels is still providing power to the main power panel?
Thanks ... Peter

Mediumed | March 9, 2019

I believe the new panels would show up as grid power because it is on the other side of the gateway. To test it out maybe you could flip your main breaker off. This would test to see if your new solar panels show up as grid power and if your powerwall would take over on a grid outage. At least I would try that. I am no electrician but it seems like a good test to me.

Patrick | March 9, 2019

What type of inverters were installed with the original system and the new non-Tesla panels?

peterjs | March 10, 2019

Thanks for responding - my feedback:
Mediumed - good idea - will try the test that you suggest
Patrick - not sure of inverter type on original system installed over 4 years ago by Solar City - new non-Tesla installation is LG NeON2 panels with Enphase IQ7 Microinverters

peterjs | March 10, 2019

Feedback to Mediumed before I try turning off the main breaker:
Do you know if the Tesla App's Power flow diagram reflects no power present from the grid when the grid loses power? The reason that I ask is that without some sort of loss of grid power indicator, I will only get the 2nd set of panels to potentially show up in the app as grid power if the original set of panels and what's stored in the Powerwall are together not generating enough power to satisfy the power required for the house and therefore, the main power panel gets hit up for power. Make sense? Thanks ... Peter

Mediumed | March 10, 2019

Peter unfortunately I don't know enough about it. I have had my system online for only about 3 weeks now and I haven't experienced an outage yet. I may take my own advice and test out the system by flipping the main breaker off to see how everything responds. I know that solar panels with micro inverters will not work on a power outage or at least that's what iv'e been told. So I would think that your normal original setup will work just fine on a grid outage but don't really know for sure. Maybe someone with a little more knowledge will chime in. I don't think that there is any harm in flipping the main breaker off and take note of what happens. If you do, let us know what you find.

Patrick | March 11, 2019

Without seeing the schematics I’ll bet your original Tesla generator is complexly oblivious to the existence of the new panels and inverter. During a grid failure, it’s likely the new Enphase inverters would shutdown for grid safety just like they would normally do in a non-PW2 configuration. Thus, Without a custom integration of some kind, the Tesla inverters/Gateway/PWs would likely never see the new generator at all.

peterjs | March 13, 2019

Patrick, thanks for the feedback.
Is it a feature of the EnPhase inverters to shut off in the case of grid failure? I assume that this is NOT the case for the Solar City panels as they are installed behind the gateway box which I assume has enough smarts to allow the Solar City panels to continue to charge the Powerwall in the event of grid failure?
BTW, on your oblivious comment, this would mean that when I see power coming in from the grid in the Tesla iPhone App's power flow diagram, this power cold be coming from the 2nd set of solar panels and not the grid - right?
Thanks ... Peter

Patrick | March 13, 2019

For safety reasons most municipalities and utility companies require residential solar generators to either shut down production or completely disconnect from the grid during power outages.

Assuming code compliance, in your case it’s likely your Enphase system would sense grid failures and simply stop production until the grid comes alive again.

When the backup gateway in your original Tesla generator senses a grid outage, its auto transfer switch quickly activates, disconnecting the grid from the generator and switching your home loads to run on the panels, inverters, and PW2s. Assuming correct sizing, the PW can then charge during the day from excess solar generation and run your home loads at night. When the grid comes alive again the backup gateway simply reconnects the grid.

As far as the power flow diagram on the Tesla app is concerned, when the grid is up I’m pretty sure the sensors feeding the app have no idea how much energy is being provided by the grid vs. the Enphase system as they are physically connected together. Not sure if that’s what you’re asking....

peterjs | March 14, 2019

Patrick, got it on my Enphase panels shutting down on grid failure. Given this, this means that the Gateway should be able to detect a grid down situation as as the Enphase stops putting power to the main panel.
At this point, I'm satisfied that the Powerwall will kick in to power the house if the grid goes down but the "power from the grid" info in the power flow diagram is bogus as it cannot distinguish between power coming from the grid or power from the main power panel where the 2nd set of solar panels is installed. Thanks ... Peter