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V4 of app drops Balanced/Cost Saving (Advanced Time-Based Control) options. Replaced with Time-Based Control

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jboy210

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Dec 2, 2016
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Northern California
I am trying to figure out why my system was pulling from the grid instead of powerwalls at unexpected times (like all weekend).

I believe it is because V4 drops the Advanced option with its Balanced and Cost Savings sub-options. The replacement is Time-Based Control which is purely time-based. This means that on my plan that has peaks M-F 4-9 PM only, the system will pull from the grid all weekends rather than using pulling from the fully charged Powerwalls after solar power drops off at night. As a result, we have pulled power from the grid this entire weekend while the Powerwalls sit there idle at 100%.

Is anyone else seeing this behavior?
 
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Others have commented about this in this thread:

I'm curious about a couple of things:

1) During Peak hours, does it send all solar generation to the grid or does it prioritize the house and send the remainder to the grid?

2) When recharging Powerwalls in the morning during Off-Peak hours, does it send all solar to the Powerwalls or does it prioritize house consumption and send the remainder to the Powerwalls?

I realize you may not know the answers yet but you will in a couple of days.
 
Based on what I know (direct observation plus discussion of people who have switched between app version 3 and version 4), I believe the "time based" control is exactly the old cost-savings mode. Specifically I had my system in cost-savings mode and after the new app, it's in time-based mode and I'm unable to tell any difference in behavior.

Bruce.
 
Yes. The APP automatically changes it to what use to be Cost Savings. The only way to change it back to balanced is to have an older version of the APP to change it there. But once you open the new APP it will change it back to Cost Savings
Another thing I noticed when I went to the old APP on my iPad is that this APP automatically switched my settings from Balanced to Cost Savings. I had to go and switch it back to Balanced on the old APP.

ETA: It keeps switching it back to costs savings every time I open the APP on my phone.
 
Based on what I know (direct observation plus discussion of people who have switched between app version 3 and version 4), I believe the "time based" control is exactly the old cost-savings mode. Specifically I had my system in cost-savings mode and after the new app, it's in time-based mode and I'm unable to tell any difference in behavior.

Bruce.
I think it is different because even at night in the new time-based mode, I see my system pull from the grid even though the powerwall is full. Before it would use the powerwall down to the threshold and only then switch to pulling from the grid. This is backed up by looking at the Impact screen for the last 2 Saturdays, showing before and after V4 of the app.
Date SW Solar PW Grid
8/22 V3 58% 36% 6%
8/29 V4 44% 5% 51%

The only reason I even have 5% PW is that I manually killed the grid on Sunday (8/29) trying to troubleshoot this issue. The previous day (8/28) the numbers were

Date SW Solar PW Grid
8/28 V4 37% 0% 63%

I wonder if Tesla made an error in their programming or purposely made these changes to decrease non-outage PW cycles.

I am on PGE TOU-B, not on any EV plan. And the only way I could get the system to use the Powerwalls on the weekend was to set the system to Self-Powered.

I am going to leave it in Self-Powered today and will see how it handles the 4-9 Peak. Hopefully, that is factored into the algorithm, and the system will have its previous behavior of pulling from the grid in non-peak to ensure the PWs are at 100% entering the peak. But, I suspect it will not do this.
 
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I am going to leave it in Self-Powered today and will see how it handles the 4-9 Peak. Hopefully, that is factored into the algorithm, and the system will have its previous behavior of pulling from the grid in non-peak to ensure the PWs are at 100% entering the peak. But, I suspect it will not do this.
Self Powered does not factor in peak and non-peak. It has no idea when your peak period ends or begins. Your system will just use solar and then once solar isn't enough to power you house, the battery will supplement the difference. Once solar is gone, your battery will power your house until you reach your reserve level. After that it will use the grid until solar powers again the next day.

The main difference between Balanced and Cost Savings was how it behaved during partial peak. During partial peak Cost Savings behaves exactly the same as during peak (all solar going to the grid and PW powering the house). Whereas with Balanced partial peak behaved more like Self Powered (all solar going to the house with excess to the grid, then when solar wasn't enough the PW will supplement the solar to power the house.)

When charging the PW both Balanced and Self-Powered behave the same. All solar to the house and excess to the PW until the PW is full. With Cost Saving all solar goes to the PW until they are full and the house is powered only by the grid. Only after the PW are full does solar start supplying the house with excess to the grid.
 
Self Powered does not factor in peak and non-peak. It has no idea when your peak period ends or begins. Your system will just use solar and then once solar isn't enough to power you house, the battery will supplement the difference. Once solar is gone, your battery will power your house until you reach your reserve level. After that it will use the grid until solar powers again the next day.

The main difference between Balanced and Cost Savings was how it behaved during partial peak. During partial peak Cost Savings behaves exactly the same as during peak (all solar going to the grid and PW powering the house). Whereas with Balanced partial peak behaved more like Self Powered (all solar going to the house with excess to the grid, then when solar wasn't enough the PW will supplement the solar to power the house.)

When charging the PW both Balanced and Self-Powered behave the same. All solar to the house and excess to the PW until the PW is full. With Cost Saving all solar goes to the PW until they are full and the house is powered only by the grid. Only after the PW are full does solar start supplying the house with excess to the grid.
I am pretty sure you are correct about the system will not shift to sending power back to the utility to capture the high-rate offsets and powered the home from the PWs when the peak rates start. It did this automatically a week ago in Cost-Savings mode. So to get the old behavior I will anticipate manually needing to switch the system to self Powered when the peak starts. If that is the case I will have to look into writing an app to handle this switch on a daily basis.
 
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I am pretty sure you are correct about the system will not shift to sending power back to the utility to capture the high-rate offsets and powered the home from the PWs when the peak rates start. It did this automatically a week ago in Cost-Savings mode. So to get the old behavior I will anticipate manually needing to switch the system to self Powered when the peak starts. If that is the case I will have to look into writing an app to handle this switch on a daily basis.

I have used self powered mode only (no time based mode at all) since my system was installed, which was Jan 6th 2020. @skepticcyclist describes it pretty well. There is no "shifting to sending power back to the utility to capture high rate offsets".

There isnt any algorithm to it at all, really. Self powered mode just attempts to keep you from pulling ANY grid power, for as long as possible, thats pretty much it.

Powerwalls only get filled with excess power left over after the solar powers the home. Once the powerwalls are full (and ONLY when the powerwalls are full) solar will then be sent to the grid, no matter what time it is. Once solar can no longer provide enough energy to power the home, the powerwalls kick in, no matter what time it is. The powerwalls continue to power the home until they hit their reserve, whenever that is (or if that is).

In self powered mode, the powerwalls will continue to power the home in the middle of the night, down to the reserve. If you have your car setup to charge in the middle of the night, when the car starts charging it will still (quickly) drain the powerwalls down to their reserve, before pulling from the grid (or drawing the maximum your powerwalls can provide based on your charging setup and number of powerwalls).

There is capturing of offsets, etc.
 
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Yeah, they need to rename the "cost saving mode" as "PG&E and SCE both suck so use this mode if you're in California". Because the average person in the USA outside of California will not have to deal with this mode. I guess some Cali people could be luckily grandfathered into older rate plans. California's time of use rate BS necessitates monkeying with this cost saving mode unless you're h2ofun with a mammoth solar array that wildly overproduces.

My off peak ends at 3pm and doesn't start again until Midnight. You better damn believe I'm going to export whatever waning solar being generated from the solar to PG&E from 3pm to sunset. It's the only realistic way I'll generate enough credits to run things in the wintertime with the shorter months, but same TOU times.

Trying to power the house off 100% self-generation is punitive due to the way the California utilities are set up. It's like they actively discourage people from being as green as possible since optimizing for self-powered means diminished credits and getting hit with the slamboni during Winter.
 
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Yeah, they need to rename the "cost saving mode" as "PG&E and SCE both suck so use this mode if you're in California". Because the average person in the USA outside of California will not have to deal with this mode unless they're luckily grandfathered into older rate plans. California's time of use rate BS necessitates monkeying with this cost saving mode unless you're h2ofun with a mammoth solar array that wildly overproduces.

My off peak ends at 3pm and doesn't start again until Midnight. You better damn believe I'm going to export whatever waning solar being generated from the solar to PG&E from 3pm to sunset. It's the only realistic way I'll generate enough credits to run things in the wintertime with the shorter months, but same TOU times.

Trying to power the house off 100% self-generation is punitive due to the way the California utilities are set up. It's like they actively discourage people from being as green as possible since optimizing for self-powered means diminished credits and getting hit with the slamboni during Winter.
Still trying to figure this all out and do I have a lot of excess. Good chance I will which makes it fun. Trying to get a bid to connect up a 100 amp subpanel in the garage, and then maybe run 3 tesla EV chargers. And one gets a 30% write off up to 1K. Then if I find I have way more power than I can use, I can offer low rate EV charging. :)
 
Still trying to figure this all out and do I have a lot of excess. Good chance I will which makes it fun. Trying to get a bid to connect up a 100 amp subpanel in the garage, and then maybe run 3 tesla EV chargers. And one gets a 30% write off up to 1K. Then if I find I have way more power than I can use, I can offer low rate EV charging. :)
Good idea to sell some of that excess power.

But, you may have some tough competition for Tesla charging soon. There is a Supercharger going in at the Raley's in Auburn.
 
Yeah, they need to rename the "cost saving mode" as "PG&E and SCE both suck so use this mode if you're in California". Because the average person in the USA outside of California will not have to deal with this mode. I guess some Cali people could be luckily grandfathered into older rate plans. California's time of use rate BS necessitates monkeying with this cost saving mode unless you're h2ofun with a mammoth solar array that wildly overproduces.

My off peak ends at 3pm and doesn't start again until Midnight. You better damn believe I'm going to export whatever waning solar being generated from the solar to PG&E from 3pm to sunset. It's the only realistic way I'll generate enough credits to run things in the wintertime with the shorter months, but same TOU times.

Trying to power the house off 100% self-generation is punitive due to the way the California utilities are set up. It's like they actively discourage people from being as green as possible since optimizing for self-powered means diminished credits and getting hit with the slamboni during Winter.

While I know you and others have issues with the CA rate plans, I think this mode continues to be applicable to anybody with a TOU rate plan (with more than a ~10% difference, to account for PW losses) and those do exist outside CA, and I expect they will continue to spread. And, they did rename it - as far as I can tell there are now two modes "Self-Powered" and "Time-Based Control".

As seems to be Tesla's pattern, they are clearly trying to simplify things. I don't like how they have done that (in my case, I would rather the old backup-only option over self-powered/100% reserve,) but I expect that they are finding that for most customers, fewer options are better. And they likely found that most customers wouldn't know the difference in behavior with backup-only vs self-powered/100%, and I am guessing they found most customers (not on this forum) wanting time-based control preferred and better understood the cost saving option.

I continue to hope at some point they will officially support an API that will allow advanced users to directly manage their systems, including approximating the missing modes and setting up different rules that better match their desired usage.
 
While I know you and others have issues with the CA rate plans, I think this mode continues to be applicable to anybody with a TOU rate plan (with more than a ~10% difference, to account for PW losses) and those do exist outside CA, and I expect they will continue to spread. And, they did rename it - as far as I can tell there are now two modes "Self-Powered" and "Time-Based Control".

As seems to be Tesla's pattern, they are clearly trying to simplify things. I don't like how they have done that (in my case, I would rather the old backup-only option over self-powered/100% reserve,) but I expect that they are finding that for most customers, fewer options are better. And they likely found that most customers wouldn't know the difference in behavior with backup-only vs self-powered/100%, and I am guessing they found most customers (not on this forum) wanting time-based control preferred and better understood the cost saving option.

I continue to hope at some point they will officially support an API that will allow advanced users to directly manage their systems, including approximating the missing modes and setting up different rules that better match their desired usage.
Tesla clearly needs to create an "Advanced Mode" for users that want it. My top requests for this new mode:
  • Never discharge during Off-Peak (toggle)
  • Scheduled Self-Powered Mode (behavior for designated TOU period)
  • Grid Charge to X% during Off-Peak (if allowed)
The only other way to make the system smarter is to allow the user to input their full rate schedule for consumption and feed-in. That would make the system work better in uncommon cases like "Free Nights Plan" and low reimbursement feed-in tariffs. It could also account for things like Non-Bypassable Charges. Since I am in California and have the same Peak times 7 days a week, the default TBC behavior actually works well for me (PG&E EV2-A). Cost Saving Mode worked less well when I didn't have generation during the Off-Peak period (PG&E EV-A)
 
Tesla clearly needs to create an "Advanced Mode" for users that want it. My top requests for this new mode:
  • Never discharge during Off-Peak (toggle)
  • Scheduled Self-Powered Mode (behavior for designated TOU period)
  • Grid Charge to X% during Off-Peak (if allowed)
The only other way to make the system smarter is to allow the user to input their full rate schedule for consumption and feed-in. That would make the system work better in uncommon cases like "Free Nights Plan" and low reimbursement feed-in tariffs. It could also account for things like Non-Bypassable Charges. Since I am in California and have the same Peak times 7 days a week, the default TBC behavior actually works well for me (PG&E EV2-A). Cost Saving Mode worked less well when I didn't have generation during the Off-Peak period (PG&E EV-A)
While I think these would be useful improvements, I would rather Tesla just expose a command that users could access in combination with home automation. That would include accessing the settings available in the app but would also include a custom mode designation. It could potentially be as simple as setting:
  • The reserve percentage
  • Priority for solar production (ordered list among home, PWs, and grid)
  • Flag for use of PWs when insufficient solar to power home
  • Expiration time (With the thought that on expiration, the system reverts to the app setting, as a fail-safe in case the home automation fails)
The above should support most use cases (it does exclude grid charging, only because Tesla currently does not generally allow it, so that battle needs to be fought before there is a point to having that feature.) This would be used with home automation to operate the system as desired, include handling TOU rates, seasonal logic or upcoming weather (clouds, thunderstorms.) Overall, Tesla could maintain its simple app options while allowing users who want to program in more complex logic to do so, without Tesla having to do much heavy lifting - just exposing the settings in an official API.

There are certainly more things Tesla could add/expose (including grid charging if/when allowed, vehicle charging rules, off-grid handling, etc.) that would also be great. And, I am not holding out much hope that we will get beyond the unofficial APIs we have, but it would be a nice compromise for supporting advanced users while making it easier for their regular customers.
 
While I know you and others have issues with the CA rate plans, I think this mode continues to be applicable to anybody with a TOU rate plan (with more than a ~10% difference, to account for PW losses) and those do exist outside CA, and I expect they will continue to spread. And, they did rename it - as far as I can tell there are now two modes "Self-Powered" and "Time-Based Control".

As seems to be Tesla's pattern, they are clearly trying to simplify things. I don't like how they have done that (in my case, I would rather the old backup-only option over self-powered/100% reserve,) but I expect that they are finding that for most customers, fewer options are better. And they likely found that most customers wouldn't know the difference in behavior with backup-only vs self-powered/100%, and I am guessing they found most customers (not on this forum) wanting time-based control preferred and better understood the cost saving option.

I continue to hope at some point they will officially support an API that will allow advanced users to directly manage their systems, including approximating the missing modes and setting up different rules that better match their desired usage.
And open-source the API so devs can add extensions and new features.
 
I am trying to figure out why my system was pulling from the grid instead of powerwalls at unexpected times (like all weekend).

I believe it is because V4 drops the Advanced option with its Balanced and Cost Savings sub-options. The replacement is Time-Based Control which is purely time-based. This means that on my plan that has peaks M-F 4-9 PM only, the system will pull from the grid all weekends rather than using pulling from the fully charged Powerwalls after solar power drops off at night. As a result, we have pulled power from the grid this entire weekend while the Powerwalls sit there idle at 100%.

Is anyone else seeing this behavior?
i've had the exact same experience - powerwall is discharging ONLY during my peak period (5-8p on weekdays), and is sitting idle fully charged at all other times. seems to me like a significant downgrade in functionality by not having the powerwall also discharge at night down to the reserve limit
 
i've had the exact same experience - powerwall is discharging ONLY during my peak period (5-8p on weekdays), and is sitting idle fully charged at all other times. seems to me like a significant downgrade in functionality by not having the powerwall also discharge at night down to the reserve limit

I'm confused .... why would you want your Powerwalls to discharge during off-peak (low cost) time? Every time a Powerwall discharges you are losing 15% due to the round-trip losses. So it stands to reason you want the Powerwalls idle or charging during off-peak... and discharging during peak.
 
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I'm confused .... why would you want your Powerwalls to discharge during off-peak (low cost) time? Every time a Powerwall discharges you are losing 15% due to the round-trip losses. So it stands to reason you want the Powerwalls idle or charging during off-peak... and discharging during peak.
i always thought batteries need to be "exercised" to maximize their lifespans, perhaps not necessarily every single day, but certainly sitting fully charged for long periods is detrimental (i thought). i also know batteries' lifespans are affected by the number of charge-discharge cycles, so it's a balance between cycling and leaving fully charged for long periods...am i misinformed about these perceptions?

i understand there are round-trip losses, but i don't really care about those losses (compared to maximizing the batteries' lifespans) except in a grid outage.