neither one of those (stormwatch or car charging) has anything to do with the setting the battery reserve level during normal operation.
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Tesla App Utility plan configuration: Multiple Peaks, Buy/Sell Behavior, etc
- Thread starter JayClark
- Start date
neither one of those (stormwatch or car charging) has anything to do with the setting the battery reserve level during normal operation.
You're right. My mistake.
But if I set 20% backup, how do I set it so it starts using the backup at 5am?
You would need to look for some third party tool that reduces the reserve to 0 at 5am. I am not understanding what you are trying to accomplish, myself, but I'm not saying I need to, either (lol).
skepticcyclist
Member
In the Tesla APP go to Settings -> PowerWall -> in Operational Mode select “Self Powered”
If you rather still use time based control so it also starts to use your battery during the peak. Then go to Settings -> PowerWall -> in Operational Mode select “Time Based Control”. In time based control select “Utility Rate Plan” and edit the the schedule to have peak period start when you want and end when you want. You will use battery during this peak period.
I'd rather not use time-based control because some days I never run out of power, other days I run out of power a little bit earlier (not sure why tbh).
Setting it to self-powered, which it's currently set to, does not have an option to reserve 20% until 5am then use whatever power is remaining as would be ideal because 20% should be more than enough to last me from 5 - 8am
Setting time of use unfortunately is the only potential solution at this time, but it's not a great solution as that means I end up with a lot of extra energy that I never got a chance to use, as I started using energy from the grid from say midnight until 5am for example.
Additionally, the main reason I don't like using time of use is because the Tesla app is awful at it. For example, I turned it on and currently have it set to stop using power wall energy and switch to grid energy at 12am due to peak hours.
An hour later it's still pulling power from my power walls instead of switching to grid. I got charged a bit when summer started because Tesla never switched to summer hours. Now that I'm trying to use it again, it's refusing to swap back to winter hours.
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skepticcyclist
Member
Time based control with reserve set to what you want is your best option. Just make the peak period end at 8:00am like you want
Wish there were a human with a phone at Tesla I could speak with, the chat has only been confusing.
Middle of a sunny day with charged but not full batteries during peak. Solar is exporting. Batteries are discharging an amount sufficient to cover house loads. Simple question: why are the batteries not waiting until the sun goes down?
Middle of a sunny day with charged but not full batteries during peak. Solar is exporting. Batteries are discharging an amount sufficient to cover house loads. Simple question: why are the batteries not waiting until the sun goes down?
If you're on time-based control, the system assumes that you want to export as much solar as possible during peak rate periods in order to maximize your credit. If you don't want this, you can switch to self-consumption where the batteries just cover any excess demand. That way the batteries won't discharge until solar can't cover the house loads. They'll charge from excess solar during the day. If you haven't already seen it, here's Tesla's documentation on the modes: Powerwall Modes | Tesla Support
Using TOU, but peak is now all day so there is no battery charging during the week. With roundtrip costs alone I’d expect no discharge while there is already plenty of solar to use and export. PW will just have to reimport those sunny day kWhs on Saturday when they could have displaced some dark hour grid consumption.
If I switch to self-powered won’t the PW just drain when the car charges? Right now the car charges with excess solar if it happens to be home during a sunny day or in a scheduled nightcap.
I don’t have the Export Everything option so by default I have Solar Only. This is the key part “When set to ‘Solar,’ Powerwall will only discharge energy to match your home loads during high-cost time periods, forcing all solar production to export. Use this option if you wish to earn credits when energy is expensive,…”
For folks with non-bypassable charges those kWhs discharged while the sun is shining have to be reimported later at additional cost but I guess not enough to offset the period delta.
For me the batteries run out by Wednesday and I could probably get into Friday if they didn’t give back when there was enough solar.
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My system is finally ALL DONE and I'm pretty happy with it. It involved:
Now that the Powerwalls are in I look at my usage all the time. At this time of year (setting aside today, which is pretty cloudy) when I wake up the Powerwalls are in the low 40% range. I have the system configured for self powered with a 70/30 split. I'm just a bit concerned about charging the batteries up to 100% every day and discharging them to 40%. I mean I know that's what they're for but it also seems hard to believe they'll last 10 years under that load.
I could do time-based control but when I put in my rate plan (PG&E E-TOU-C) it says it won't even bother. However I've also noticed that the rates for my rateplan are the "above baseline" rates ($.37/.39) not the "below baseline" rates ($.28/.30). I don't know if that matters but doing TBC might be a way not quite use the Powerwalls so hard while still using them.
- Subpanel upgrade to Span.io panel
- 12kW SunPower PV system
- 2 Powerwalls
Now that the Powerwalls are in I look at my usage all the time. At this time of year (setting aside today, which is pretty cloudy) when I wake up the Powerwalls are in the low 40% range. I have the system configured for self powered with a 70/30 split. I'm just a bit concerned about charging the batteries up to 100% every day and discharging them to 40%. I mean I know that's what they're for but it also seems hard to believe they'll last 10 years under that load.
I could do time-based control but when I put in my rate plan (PG&E E-TOU-C) it says it won't even bother. However I've also noticed that the rates for my rateplan are the "above baseline" rates ($.37/.39) not the "below baseline" rates ($.28/.30). I don't know if that matters but doing TBC might be a way not quite use the Powerwalls so hard while still using them.
@jjrandorin Can you link me to a thread that discussed powerwall longevity? That was my main question. I don't see a way to edit my post to remove that portion of it so that it can be moved to a relevant thread, as the entire upper 2/3rds of the post are irrelevant to this thread.
There is no thread on powerwall longevity, and there is no way to manage "not charging to 100%" like the you can in the vehicles. You can set your reserve to reduce depth of discharge, but your choice is to either not discharge at all, or go from X % to 100 unless your solar wont fill up the batteries.
RKCRLR
Active Member
I'm
My personal goal is to have the Powerwalls last 20 years. If the 37.8 MWh is the actual design life then that means I should limit the annual throughput to 1.89 MWh/140 cycles per Powerwall, or an average discharge of 38%.
As mentioned, there is no way to keep your Powerwalls from charging to 100% unless you manually control them or perhaps write your own program. Powerwalls have a 10 year warranty in our applications no matter what the throughput. There are other applications where Tesla warranties the Powerwalls for 37.8 MWh aggregate throughput (2800 cycles) so that gives you an idea of the design life.
My personal goal is to have the Powerwalls last 20 years. If the 37.8 MWh is the actual design life then that means I should limit the annual throughput to 1.89 MWh/140 cycles per Powerwall, or an average discharge of 38%.
skepticcyclist
Member
Tesla says its the 70% design life, not the product design life.... but we have had this discussion before.
I see. My impression is the Powerwalls only look ahead one day for their planning. I'm not 100% sure of this though. In other words, they won't try to plan for the weekend until Friday.
Have you set a difference between the sell and buy prices in your rate plan to account for non-bypassable charges? That can help make the algorithm be a little less eager to export.
RKCRLR
Active Member
I'm a NEM2 net producer (solar + Powerwalls) on PG&E's EV2A TOU rate plan ($0.43/kWh peak, $0.42/kWh part peak, $0.25/kWh off peak winter rates) using Time Based Control and have my reserve set to 50%. I don't have an option for energy exporting and I have grid charging off. I've left the Buy/Sell prices at the default $0.43, $0.42, and $0.25 values.
I pay ~$0.03/kWh in Non-Bypasable Charges for the energy I draw from the grid. How do I explain this to the Tesla app? Do I add $0.03/kWh to the sell prices, subtract $0.03/kWh from the buy prices, or make all the buy prices $0 and all the sell prices $0.03/kWh since I'm a net producer? And how should I expect the app behavior to change over leaving the buy/sell prices as they are?
I pay ~$0.03/kWh in Non-Bypasable Charges for the energy I draw from the grid. How do I explain this to the Tesla app? Do I add $0.03/kWh to the sell prices, subtract $0.03/kWh from the buy prices, or make all the buy prices $0 and all the sell prices $0.03/kWh since I'm a net producer? And how should I expect the app behavior to change over leaving the buy/sell prices as they are?
RKCRLR
Active Member
I understand an agree - The 37.8 MWh just gives you a target where the storage falls below 70%.
I think of the NBC as the utility taking a cut from of your sell price, making the value of those kWhs that much less when you apply them as credits. That would mean subtracting from sell price.
Will it be enough? Support told me PW needs a delta of 15%
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