Adjust the reserve for power outage automatically by HS

[Thedude]

Is it possible to recognize power outage and change the reserve for power outage on the fly (by HomeSeer). Tesla Powerwall reserves some of it's capacity (as much as user chooses) for power outages. If I choose too much say 50% than my power wall operates at 50% capacity only and I will need twice as large system just to cover for occasional power outages. If I choose too little say 5% than it may not be enough to cover 1 hour of power outage. Unfortunately Tesla doesn't provide an option to put the power outage as top priority and to use as much as needed in case of power outage.
Ideally I want to have it at 1% and push it to 90% when power outage happens and back to 1% when power is restored.

[Dr. McKay]

Unfortunately this isn't possible since it's controlled through the Tesla app and not locally. I don't intend to connect to the Tesla API through this plugin since I value local control wherever possible.

That said, I don't really understand your use-case. When there's an outage, the mode you select in the Tesla app becomes irrelevant as the Powerwall will store all excess energy produced by solar (if you have solar) and will drain when the home demands more power than solar is currently producing. It couldn't operate any other way as the grid is now out of the picture. The only thing the reserve option does is determine how much Powerwall capacity will be available at the start of an outage.

Here's a detailed explanation of what each operating mode does with solar, when the grid is up:

	Charges	Discharges
Backup-only	From solar, whenever there is excess production	In small bursts throughout the day, to keep the battery healthy
Self-powered	From solar, whenever there is excess production	Whenever solar is not meeting the demands of the site, down to your reserve
Time-based control - Balanced	From solar, whenever there is excess production except during on-peak times	During all periods, minimizing exports during shoulder and off-peak, down to your reserve
Time-based control - Cost Saving	From solar, whenever there is excess production except during on-peak times	During peak and in other periods to ‘make room’ for solar based on energy forecast, down to your reserve
Storm Watch	Anytime, even from grid	Never
Grid outage	From solar, whenever there is excess production	Whenever solar is not meeting the demands of the site, down to 0%

As you can see, during a grid outage, it behaves identically to "self-powered" mode with a 0% reserve, no matter what operating mode you select.

[noelep]

Agree that this use case doesn’t warrant it - and understand the preference not to connect to the API

As an aside, one example of where I am considering automating the reserve: based on my typical energy usage. In the summer here in TX I am not often generating enough excess to get from my typical reserve (50%) to full. However, in spring/fall where we have good solar but low usage I would typically reduce my reserve to avoid topping out the battery and dumping to the grid (because we don’t have a sell-back agreement)

just something I’m tinkering with, not a feature request!

[Dr. McKay]

That's a fairly interesting use-case. I understand that you're not "officially" requesting it; I sure wish I could enable it without having to communicate with the Tesla API.

[Thedude]

Dr. McKay You said that you don't understand my use case and now you say it's "fairly interesting". Let's repeat it again to make sure we're all on the same page.

Power outage can strike any time. When it does I want all of the battery capacity available at the time of strike to be available to the power outage, not just some pre-determined % as it is now.

I paid dear money for this expensive system for two reasons only

1. To time-shift my solar production energy in order to use the stored energy when grid power is most expensive.
2. To protect from power outages.

The second one happens rarely but it is top priority and all stored energy should be dedicated to it when it happens.

Thanks for the cooperation and please let us know if your managed to implement it in your wonderful plug-in.

TheDude

[Dr. McKay]

If I'm understanding you correctly, you and noelep have different use-cases. He wants to adjust his reserve based on the time of year, and you want to use 100% of the battery capacity when an outage is ongoing. Your desire is already implemented by default; when the power goes out, the battery provides backup with 100% of its capacity.

[Thedude]

If I'm understanding you correctly, you and noelep have different use-cases. He wants to adjust his reserve based on the time of year, and you want to use 100% of the battery capacity when an outage is ongoing. Your desire is already implemented by default; when the power goes out, the battery provides backup with 100% of its capacity.

I tend to agree with you, now that I think more about it. I was confused by the term "% reserved for power outage". It made me believe that this would be the only resource used during power outage, which doesn't seem to be true now when I take a second look at it. Bottom line I have no "use case" anymore. Thanks for helping me understand.

The Dude