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Strategies for Powerwalls and Utility Demand Plans

Discussion in 'Tesla Energy' started by DanAman, Apr 29, 2019.

  1. miimura

    miimura Well-Known Member

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    If you're on this kind of demand plan and don't want to export during Peak like TBC wants to, then you should use the external automation to change the Self Powered Reserve between 100% during Off-Peak and 10% during Peak. This will actually save you more battery energy during Peak because it won't export your solar and instead let it power the A/C to the extent that it can.
     
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  2. destructure00

    destructure00 Active Member

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    #102 destructure00, Aug 18, 2020
    Last edited: Aug 18, 2020
    That's exactly what I'm doing, using @Darwin Powerwall Manager on my Hubitat hub.

    Desired behavior during off-peak is:
    - Solar charges battery first while house pulls from grid
    - After batteries are full, solar powers house with any excess being exported to grid

    Desired behavior during on-peak is:
    - Solar powers house first
    - If demand exceeds solar production, pull from batteries
    - If solar production exceeds demand, recharge batteries if needed
    - If batteries are full and solar production exceeds demand, export to grid
     
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  3. destructure00

    destructure00 Active Member

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    How long are you guys seeing for a mode or reserve level change to take effect? My Hubitat rule triggered at 3. Attributes in Hubitat updated immediately, Tesla app also shows correct settings (Self-Powered, 0% reserve), but gateway still shows PWs inactive with some power being pulled from the grid instead of the batteries.
     
  4. destructure00

    destructure00 Active Member

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    Well now that I'm looking at my usage chart, I had mistaken power from grid for power to grid, looks like solar was providing a little bit more than the house was consuming. 23 minutes into the mode change and solar is still producing just enough to power the house with AC running, hasn't touched the battery yet. Will keep an eye on it as solar tapers off this afternoon.

    Screenshot_20200818-152516.png
     
  5. Darwin

    Darwin Member

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    I'm not sure why, but with Self-Powered 100% Reserve, every once in awhile some solar was being sent to the home instead of charging the Powerwall. I didn't investigate the few times I saw this happen. It may be that the Powerwall didn't really accept the 100% reserve setting, even though it showed as 100% and plenty of time had passed. I did, however, change my automated schedule to set my off-peak hours to Backup Only mode just in case it makes a difference and haven't seen the issue since. I still set on-peak hours to Self-Powered 0% reserve.

    Using a switch as a schedule trigger or restriction would definitely be useful for many. I've been trying to keep from adding more clutter and complexity to the scheduling options interface, but maybe there is a way to implement without adding too much more UI complexity. I'll put it on the enhancement list and give it some thought. Thank you.
     
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  6. miimura

    miimura Well-Known Member

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    Self-Powered with 100% Reserve does not have the same PW charging effect as Backup. Self-Powered will still minimize grid draw whenever possible. That means that it will only charge with Surplus Solar, not All Solar. Backup and TBC can charge from All Solar. If you want to charge the batteries as fast as possible from Solar, switch to Backup Mode.
     
  7. woferry

    woferry Member

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    I'm not sure that's true, at least it wasn't true for me at lower levels, I didn't try it at 100%. In my usage, the PW charging policy seems to be driven by the Reserve level. So in Self-powered, with the current SoE at say 5% (app), raising the Reserve from 0% to 20% results in the PW taking all available solar power (I was producing less than 5kW at the time) until it reached the new Reserve, then it went back to only charging from excess solar. So it seems to me that raising the Reserve to 100% should be the same, but I'll admit I've never taken my Reserve above 20%, so I have no direct proof. But raising my Reserve from 0-20% caused my PW to charge from all solar when I last did that this past winter.
     
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  8. miimura

    miimura Well-Known Member

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    I don't normally use Self-Powered, so the actual behavior may be different than what I said. Of course, firmware changes can change the behavior too. Anyone who wants a particular behavior needs to try it for themselves and see how their system reacts to their own settings.
     
  9. destructure00

    destructure00 Active Member

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    @Darwin , another question for you, I think I know the answer already but going to ask anyway. Is there any provision for full local control of the Energy Gateway from your app? Or is it cloud-dependent? Since I'm on Hubitat, was thinking it would be nice to stay completely local and send commands directly from the Hub to the Gateway. Wondering if there's a simple way to point your app to the Gateway's IP address rather than https://owner-api.teslamotors.com

    I just got done stringing ethernet cable across the attic to the Gateway...3 days in and it seems like the WiFi connection drops a few times a day for 20-30 minutes. So far not an issue since it hasn't happened at 3 or 8pm when mode changes are sent, but it was just a matter of time.
     
  10. Darwin

    Darwin Member

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    Full support of the local gateway interface is on the to-do list of potential enhancements for the Powerwall Manager (when running on Hubitat at least. SmartThings currently appears to have an issue with handling the local gateway self-signed certificate). The local gateway API is different enough that this will require some work and I unfortunately can't commit to any timelines right now. I know this is important to many users, especially for those running on Hubitat. For me, the interface with https://owner-api.teslamotors.com has been pretty solid as of late, but I know that may not always be the case. It would also good to be ready with an alternative in case Tesla changes its web access to 2FA or otherwise changes the authentication requirements.

    There's been a little progress on this front though. The latest (July v0.2.8) Powerwall Manager when running on Hubitat does provide the following option to connect directly to the local gateway, but it is currently limited to reading (only) the non-authenticated data such as the meter aggregate data (solar, load, grid, etc power) and SOE/battery percent. It does not currently support requests requiring local gateway authentication such as reading or commanding operational mode (Backup-Only, Self-Powered, etc). If you use either of the local gateway connection options with this latest version of the Powerwall Manager (when running on Hubitat), it also provides the option to display a dashboard tile that grabs an iframe from the local gateway web page. The dashboard tile was a bit of an afterthought, but I've found it to be a pretty handy addition to my Hubitat dashboard running full time on a wall-mounted Fire 10 tablet:

    PowerWallManagerDashSmall.png PowerWallManagerConnectOptions.png

    Good call. I noticed several issues with the gateway Wifi connection when my Powerwall was installed about 1.5 years ago and I ended up running a direct ethernet cable the first week or so. The biggest issue I found was that the gateway would often fail to re-connect if my WifI was re-started. None of my other WiFi devices had this issue. I'm not sure if that issue has since been resolved, but the direct ethernet connection has been rock solid and I haven't looked back.
     
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  11. destructure00

    destructure00 Active Member

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    No worries, totally understand. Thanks for all your work on this!
     
  12. bobbyclee

    bobbyclee Member

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    Hi all,

    I'm new to this Tesla Motor Club forum... but I'm a huge Tesla fan, and eager to participate.

    This is a Solar + PowerWall + TOU Rates + Net Metering + SAVE MONEY topic.
    My PowerWalls are not behaving as expected (as I want them to behave.) I've been searching the forum and trying to see if anyone out there is encountering my use case with Time-of-Use rates and Net-metering:

    I recently had a 4x PowerWall system installed (I think it's PW2), adding to my existing Tesla solar panel system of 11 kW. I got Permission To Operate on August 16, and turned on the PowerWalls then.

    I'm in Las Vegas, Nevada, and my utility is NV Energy. I'm on TOU rates, where the summer peak price is $0.435 (with +$0.407 credit for net-metering), and off-peak rates are just $0.053 (with +$0.045 credit for net-metering).

    As you'll notice from the rates I've posted, the net-metering credits during the summer (at +$0.407) are huge multiples from the evening off-peak prices ($0.053), at almost 8x. This means that for every 1 kW I send to the grid via net metering during my peak hours (from 1 pm to 7 pm), I can get credit from NV Energy, and it's worth like 7.6 kW of electricity off-peak.

    Using my PowerWalls, I'm simply trying to arbitrage the rate differences using net metering:
    1) Mornings during off-peak (until 1 pm):
    a) Use solar to charge up the PW battery (the morning solar is
    enough to fully charge the PW)
    b) Send excess solar to grid for +$0.045 / kW.
    2) Afternoons/Evenings during peak (from 1 pm to 7 pm):
    a) Use 100% of PW to power 100% of house (My fully charged PW battery has
    enough to power the house)
    b) Send 100% of solar to the grid, to earn the net-metering credits at +$0.407 / kW.
    3) Evenings off-peak starting at 7 pm:
    a) STOP
    discharging PW, and save the remaining battery level for next day
    b) Use the Grid for 100% of load for the whole off-peak duration

    Is this possible? I ASSUME the answer is YES, as it's so simple! (the post quote above seem to show evidence that this DOES indeed work for some
    people out there...)

    The Time Based Controls + Cost Savings mode should do it.... but the reason I'm posting this is because my PW system is NOT doing it for me.


    Here's what happens on my system, referencing the 3 points I listed above:
    1) Yes, (a) and (b) both happen.
    2) No. Here is what happens during peak period:
    - When Solar output is higher than the Household load, only the excess solar goes to the grid, and PowerWall doesn't contribute at all. This means that there's valuable Solar that is NOT going back to the grid for net-metering credits, whereas my charged up PW is sitting idle.
    - When Solar output is lower than the Household load, then the PW kicks in to supply the difference of what the Solar produces, from what the Household load requires. Yes, there is no pull from the grid (which is good), but unfortunately, the Solar still is NOT sent to the grid for net-metering credits (which would be awesome), as I would GLADLY prefer to use PW to power the house during the whole Peak period, and sending ALL 100% Solar to the grid for the high-rate of net metering credits.
    3) Nope... the PW will sometimes continue to discharge at night, which is mind-boggling, because we all know that charge-discharge of PW results in at least 10% penalty due to inefficiency.


    Why is my system not behaving the way I like? Any clues?
    I'm already on TBC and Cost Saving mode. I've set the Peak times properly in the app.

    Do I need to reboot the Gateway or are there better ways to fine-tune what the PowerWalls do?

    thanks,
    Bobby
     
  13. bobbyclee

    bobbyclee Member

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    This is EXACTLY what I want.

    Can someone (or wraithnot?) please TEACH me how to get this working on my PowerWall setup?
    My current PowerWalls are NOT behaving like this.

    My setup:
    - NV Energy with TOU rates and Net Metering
    - 11 kW Solar system
    - 4 x PowerWall (PW2)
    - Advanced Time-Based Controls, set to Cost Saving mode
    - Reserve set at 50%
    - Price schedule: Peak is 1pm to 7 pm (weekdays only)

    and I've tried both using Shoulder (from 8 am to 1 pm, and from 7 pm to 10 pm) and also NOT using Shoulder (so just Peak and non-Peak).

    Still no avail... so any help would be appreciated.

    thanks,
    Bobby
     
  14. Dukeybootie

    Dukeybootie Member

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    This is my same strategy. It has been working exactly as intended using TBC-cost savings with no shoulder and peak hours set to 2-8pm. Not sure what is preventing you from duplicating what I am getting. Maybe the app needs more time to adjust to your system?


    Screenshot_20200829-102642.png
     
  15. bobbyclee

    bobbyclee Member

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    Is it typical for the app/system to need to time learn & adjust to your system? How long does that take?

    I called Tesla Energy, and frankly they just weren't being very helpful. They keep insisting that my PW system is working as intended.
     
  16. Dukeybootie

    Dukeybootie Member

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    It took one or two days IIRC. Don't forget that weekends and weekdays are different. I tried experimenting with shoulder periods before realizing it would never do what I wanted it to do that way. Bottom line with TBC-cost savings mode is that there should never be any PW discharge during off peak hours, and the home should draw solely from PW during peak hours while sending all solar back to the grid. If that is not happening, something is wrong with your settings or the app.
     
  17. Eddie Lee

    Eddie Lee New Member

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    Darwin, how did you access the WIFI port? Also which Gateway do you have 1 or 2?
     
  18. blueice89

    blueice89 Member

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