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PW intelligence driving me bonkers

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I switched to EV-TOU2 plan in August where peak is now 4p-9p. I expected PW to charge from solar, then cover the peak period. Typically, we do not use a lot of power during peak. House consumes about 1 KW per hour, give or take. Average 5kwh. Some days we use the oven which will bump that, but 5 kwh is average. Obviously, 5kwh is nothing for 2 PW's. The system started getting "smart" and stopped topping off the PW choosing to export more solar to the grid. Whatever, it is doing its thing.

Then the heat wave came.

I adjusted the reserve when it started warming so the PW's would charge to 100% to cover the AC during peak. AC ran for maybe 10 days with PW charging to 100% and nearly down to 20% (Reserve) by 9pm. Then the heat wave passed, PW kept charging to 100% afterwards and I stopped paying attention daily.

It's warming up again. I expected to have to run AC next week, but it got to 90 today and I turned on the AC at 1p or so. Didn't even think to check the PW in the app. At 4:15, I saw PW was down to 79%. I look at the history and the PW did not top off last night, but it did the the previous 7 days. It only started charging at 3p today when I turned on the oven and didn't get far until peak hit.

Is there any tweaks to encourage the PW to top off daily? I'd prefer to have enough power to run the AC in the event we need to. Most of the year we do not run the AC, but the Aug/Sept and into Oct can be a bit warm or muggy historically.

thanks.
 
I'm guessing you have a super-off-peak period overnight. When there are three rates, the Powerwalls only charge as much as they think they need to to get through peak during the middle rate. As Wayne said, one way to get them to charge up completely is export everything. If they're set up that way, they'll also discharge to the reserve during the peak period.
The other way would be to change the rate plan so there's only one rate during the off-peak hours (i.e., remove the super-off-peak rate). That way all solar would go to the batteries until 4pm or the batteries are full.
 
I switched to EV-TOU2 plan in August where peak is now 4p-9p. I expected PW to charge from solar, then cover the peak period. Typically, we do not use a lot of power during peak. House consumes about 1 KW per hour, give or take. Average 5kwh. Some days we use the oven which will bump that, but 5 kwh is average. Obviously, 5kwh is nothing for 2 PW's. The system started getting "smart" and stopped topping off the PW choosing to export more solar to the grid. Whatever, it is doing its thing.

Then the heat wave came.

I adjusted the reserve when it started warming so the PW's would charge to 100% to cover the AC during peak. AC ran for maybe 10 days with PW charging to 100% and nearly down to 20% (Reserve) by 9pm. Then the heat wave passed, PW kept charging to 100% afterwards and I stopped paying attention daily.

It's warming up again. I expected to have to run AC next week, but it got to 90 today and I turned on the AC at 1p or so. Didn't even think to check the PW in the app. At 4:15, I saw PW was down to 79%. I look at the history and the PW did not top off last night, but it did the the previous 7 days. It only started charging at 3p today when I turned on the oven and didn't get far until peak hit.

Is there any tweaks to encourage the PW to top off daily? I'd prefer to have enough power to run the AC in the event we need to. Most of the year we do not run the AC, but the Aug/Sept and into Oct can be a bit warm or muggy historically.

thanks.
Is your rate schedule accurately modeled in your app?

I find that the Tesla versions of the rate schedules are very inaccurate and do not properly reflect the actual price of power at various times of day and year.
 
Export Everything?

Cheers, Wayne
I'm going to try this after adjusting the buy price a bit. The last few times I tried, the PW's dumped all the power then started buying it back during peak. This incurs non-bypassable charges with NEM 2.0.
I'm guessing you have a super-off-peak period overnight. When there are three rates, the Powerwalls only charge as much as they think they need to to get through peak during the middle rate. As Wayne said, one way to get them to charge up completely is export everything. If they're set up that way, they'll also discharge to the reserve during the peak period.
The other way would be to change the rate plan so there's only one rate during the off-peak hours (i.e., remove the super-off-peak rate). That way all solar would go to the batteries until 4pm or the batteries are full.
Correct, three rates. I'll try export everything and see how that behaves, otherwise I'll remove the super off peak pricing.
Is your rate schedule accurately modeled in your app?

I find that the Tesla versions of the rate schedules are very inaccurate and do not properly reflect the actual price of power at various times of day and year.
Yes, I just checked. Thanks for suggesting.
 
I'm going to try this after adjusting the buy price a bit. The last few times I tried, the PW's dumped all the power then started buying it back during peak. This incurs non-bypassable charges with NEM 2.0.
Yes, under NEM 2.0, your sell price is ~$0.03 less than your buy price. I'm under NEM 1.0 and saw the same behavior, so I artificially lowered my sell price a couple cents, and now it attempts a smooth landing at the reserve level at the end of Peak.

Cheers, Wayne