Asking help: Solar power is not used in "off-grid" mode

[SuperCarrot]

I have 4kW panel and 1 PW+. I did a test for the "off-grid" mode by using the "Go Off-Grid" button in the app. It's strange that it uses power from battery rather than solar panel. The test is around noon, so there's full sun and plenty of solar power. Why it doesn't use solar power? Does anyone have similar experience?
Another question is, my house is partial backup. The range is NOT in backup. But I can still turn on and use it in "off-grid" mode, the system didn't switch back grid by itself. It just shows some non-sense data and the data keeps changing. If click the yellow exclamation icon, it shows error message. Does anyone know is this normal? Why the non-backup device is still working in off-grid mode?

One more question, can I request Tesla to change my backup device? My range is not in backup, but SPA is in backup. This design doesn't make sense. I hope the range is in backup rather than SPA. They are both 50A devices.
Thank you.

 

[ucmndd]

Because your powerwall is charged to 99%, there is nowhere for any excess solar generation to go, so your system curtails solar production until you’ve discharged the battery enough. Try the test again with your powerwall charged to 80% or so and you should see that your solar production stays online and your house loads will use that first.

As for your other question, I notice the same - my non-backup loads continue to be powered by the Powerwall when I use the “go off grid” feature. In the case of an actual grid outage (or me disconnecting the grid by opening the main breaker) those loads are powered down as I would expect.

And finally, yeah - if your system was installed recently, I’d get them to come correct the problem with the range and spa. Sounds like they mixed up the circuits during install.

 

[SuperCarrot]

Because your powerwall is charged to 99%, there is nowhere for any excess solar generation to go, so your system curtails solar production until you’ve discharged the battery enough. Try the test again with your powerwall charged to 80% or so and you should see that your solar production stays online and your house loads will use that first.

As for your other question, I notice the same - my non-backup loads continue to be powered by the Powerwall when I use the “go off grid” feature. In the case of an actual grid outage (or me disconnecting the grid by opening the main breaker) those loads are powered down as I would expect.

And finally, yeah - if your system was installed recently, I’d get them to come correct the problem with the range and spa. Sounds like they mixed up the circuits during install.

Thanks for your reply, I understand your explanation. But my case looks different. In the off grid test, I tried to turn on water heater, the house total consumption turned to 4.4kW. The diagram indicated all the 4.4kW came from battery rather than solar panel. When I went back grid, i can see 2.6kW from solar, and the rest from grid. I will try to test it tomorrow again and take the screenshot.

 

[jjrandorin]

If you want to test, dont use "off grid" in the app. Its only going to simulate turning things off that it can, which is stuff connected through the gateway.

Test by turning your physical main breaker off. If you do that, you will find that only the backed up loads will work, as you expect.

As for "why is solar not being used?" @miimura addressed that already. It would be, once your powerwalls drained some.

In regards to " can I get tesla to swap these loads?" Maybe. It depends on how long ago you were installed, and whats on the plans. if tesla made a mistake and backed up the wrong load? Probably. If they didnt, and thats whats on the plans, I have no idea if tesla will do that for you, or what they might or might not charge for doing so, if what they did is whats on the plans.

 

[Zinc_Saucier]

Another question is, my house is partial backup. The range is NOT in backup. But I can still turn on and use it in "off-grid" mode, the system didn't switch back grid by itself. It just shows some non-sense data and the data keeps changing. If click the yellow exclamation icon, it shows error message. Does anyone know is this normal? Why the non-backup device is still working in off-grid mode?

That’s because the range can still access grid power since it’s not behind the gateway. When the grid is up the solar/PW need to see the whole house consumption so it can “push” power to cover those loads even through they aren’t backed up, but once the grid is down, the connection between the non backed up and the solar/PW is severed. Now if you physically threw the breaker closest to your meter, only the backed up loads would work.

 

[ucmndd]

Thanks for your reply, I understand your explanation. But my case looks different. In the off grid test, I tried to turn on water heater, the house total consumption turned to 4.4kW. The diagram indicated all the 4.4kW came from battery rather than solar panel. When I went back grid, i can see 2.6kW from solar, and the rest from grid. I will try to test it tomorrow again and take the screenshot.

No, I understand what’s happening, your explanation is clear, and my response is consistent with what you’re asking.

When the grid is down and your powerwall is fully charged, the gateway turns your solar production OFF until your Powerwalls have discharged some. Your panels will not be re-enabled until the batteries drain some. As I said, try your test again with the Powerwalls at 80% or so and it will work the way you think it should.

 

[SuperCarrot]

You guys are correct. I turn off the main breaker, then the system works as expected. Thank you all.
My system started working from Nov 2021, I will communicate with Tesla to see if possible to include range in backup.

 

[jjrandorin]

You guys are correct. I turn off the main breaker, then the system works as expected. Thank you all.
My system started working from Nov 2021, I will communicate with Tesla to see if possible to include range in backup.

If by "include" you mean "swap", they may or may not be willing to do that based on the fact you said the range and the have the same amp breaker. They may not have the same startup surge, though.

Its not necessarily as simple as just swapping things around in the panel. It "could" be, but this depends on the actual specifications on each piece of equipment, what their startup load is, etc.

I keep forgetting that the powerwall+ is supposed to be able to deal with current inrush differently than the powerwall 2s most of us have. For a regular powerwall 2, nothing over 30amp would be in the backup loads panel, if you only had one.

In any case, even if tesla tells you "no" on swapping those loads around, I wouldnt stress about it too much. There is no way you would actually want to run a 50amp range on one powerwall+ in an actual "grid down" situation. You might think you would, but when you see how much power running that range would take from your powerwall, you would quickly shut it off.

 

[SuperCarrot]

If by "include" you mean "swap", they may or may not be willing to do that based on the fact you said the range and the have the same amp breaker. They may not have the same startup surge, though.

Its not necessarily as simple as just swapping things around in the panel. It "could" be, but this depends on the actual specifications on each piece of equipment, what their startup load is, etc.

I keep forgetting that the powerwall+ is supposed to be able to deal with current inrush differently than the powerwall 2s most of us have. For a regular powerwall 2, nothing over 30amp would be in the backup loads panel, if you only had one.

In any case, even if tesla tells you "no" on swapping those loads around, I wouldnt stress about it too much. There is no way you would actually want to run a 50amp range on one powerwall+ in an actual "grid down" situation. You might think you would, but when you see how much power running that range would take from your powerwall, you would quickly shut it off.

Thanks, it makes sense. Actually my range typically consumes less than 4kW since I won't turn on more than 2 stoves at same time. Yeah I would not stress too much if they refuse to swap it, there are some other ways to cook even if range was down.

 

[jjrandorin]

Thanks, it makes sense. Actually my range typically consumes less than 4kW since I won't turn on more than 2 stoves at same time. Yeah I would not stress too much if they refuse to swap it, there are some other ways to cook even if range was down.

Even at that usage, it means an hour of cooking on the range would take up almost 1/3 of your total battery storage, not counting anything else that was running in the home, since 1PW starts with 13.5 (ish) of storage.

 

[ucmndd]

In any case, even if tesla tells you "no" on swapping those loads around, I wouldnt stress about it too much. There is no way you would actually want to run a 50amp range on one powerwall+ in an actual "grid down" situation. You might think you would, but when you see how much power running that range would take from your powerwall, you would quickly shut it off.

All true, but you probably wouldn’t want your spa being backed up either. As things sit now OP’s gonna need to remember to run out and flip the spa breaker to keep it from draining the PW. My spa heater draws a good 5kw when it’s running…

 

[SuperCarrot]

Even at that usage, it means an hour of cooking on the range would take up almost 1/3 of your total battery storage, not counting anything else that was running in the home, since 1PW starts with 13.5 (ish) of storage.

Understood.

 

[SuperCarrot]

All true, but you probably wouldn’t want your spa being backed up either. As things sit now OP’s gonna need to remember to run out and flip the spa breaker to keep it from draining the PW. My spa heater draws a good 5kw when it’s running…

Yeah, it's a good point.