Energy Products

1) Storm Watch and 2) Charging Wall Battery Off Grid

1) As best I can tell from looking at the Tesla app, Storm Watch appears to only look for hurricanes and ice storms. If there is a band of thunderstorms coming through, it looks like it won't kick into gear. Correct?

2) Is there a way to trigger charging of the Wall Battery from the grid? In other words, if the battery is low and sunlight has been low, and a storm is incoming, is there a way I can tell the battery to charge from the grid?

Thanks for the help.


  • edited March 22
    Nope. Unless you live in Great Britain or Australia.

    U.S. electrical utilities don't want the competition, and have very effective lobbyists.
  • bpbp
    edited November -1
    Storm Watch should only be triggered when there is an event anticipated that could result in power outages.

    In the US, if the federal tax credit is used to help pay for solar panels/PowerWalls, the PowerWalls cannot be charged from the grid (with the possible exception of Storm Watch). Plus, charging from the grid (except for Storm Watch) will change the PowerWall warranty.
  • edited March 23
    OP I have had "Storm Watch" kick in when Tesla thinks there is bad weather coming and nothing happens, and I have had it not kick in when it's raining hard.
    As I understand it, they are still on the learning curve of what constitutes the criteria for "Storm Watch".
    Also, "Storm Watch" for one area may also include a much wider area, some of which is not affected.
  • edited March 24
    It's also interesting that one of the criteria for Stormwatch" isn't planned, local outages, that can last a day or more.
  • bpbp
    edited November -1
    If planned local outages are anticipated, probably a good reason to change the configuration to backup with a 95-100% charge, and pre-charge the PowerWalls from the solar panels prior to the anticipated outages - just takes longer to do this than using Storm Watch with charging from the grid.
  • edited April 18
    github DOT com/vloschiavo/powerwall2
  • edited August 2
    Storm Watch with hurricane coming:

    For the last 2-3 days, my app has said storm watch is active. I live on the FL East coast and we have a hurricane nearby. Its probably going to be mild, but max wind speeds are supposed to be around 1pm today. Its 9:33am currently, so relatively close now and the wind is definitely whipping outside already. We frequently lose power even with minor storms, so I expect we will probably lose power even if its not a direct hit. On the first day the Storm Watch became active, my powerwalls were at 96% (I always leave it in backup-only mode and it hovers between 96% and 99%). It did not pull any power from the solar panels that first day. Around midnight that first night, it started pulling 13kW from the grid and quickly charged to 99%. I guess its cool that it can pull power from the grid when an outage is anticipated, but at that point the hurricane was still days away and it was beautiful outside. It easily could have just charged from solar the previous or following day. Since then, it has not charged at all, either from solar or from the grid. It is now at 97% and max wind speeds are expected to be only hours away. In reality, I don't think there's going to be a huge functional difference between 97% and 99%, but its odd that it decided to pull from the grid and charge up when the hurricane was still far away but its not using the small amount of solar I'm getting through the clouds right now to top up the battery. Its exporting extra power to the grid. I'd prefer that it send solar to the battery right now to keep it topped up. I know I could go flip my main breaker and force it to do that, but then it will shut the inverters off when the battery is full so I'll lose some solar production. In this case storm watch seems to be pretty useless. I suppose if I hadn't been in backup-only mode, it would have charged me up with grid power from a much lower level and then 97% would be a big improvement. On backup-only mode, at least for me during my first storm with the powerwalls, it didn't really make any difference. I guess I'll leave it on, because it doesn't seem to hurt anything, but it definitely needs more fine tuning.
  • edited August 2
    As one of the conditions for accepting an SGIP grant from my utility (~$6k!), I am required to run my house on my two PWs during peak usage times (4-9PM). During Summer, I export PV production to the grid during that time. I set my reserve to 50%, but haven't routinely depleted them to that level.

    Prior to accepting the SGIP grant, I ran in backup only mode, as I live in earthquake and brush fire country. I wish there was a "QuakeWatch" or "FireWatch" mode so that my PWs could charge from the grid if there's a >4.0 quake (increasing the odds of "The Big One") or during Santa Ana conditions (where utilities shut off transmission lines to reduce fire danger). Either of those conditions are easily detected or predicted.

    I agree that the firmware in the TEG could be more intelligent.
  • Here in Massachusetts my powerwall went into "Storm Watch" three times in the past two days. The tropical storm was supposed to come through Tuesday afternoon.

    On Monday around noon it went into Storm Watch and then turned off Monday around 8 PM.

    Tuesday morning (4 AM) it went back to Storm Watch and then turned off around 1 PM Tuesday.

    Tuesday afternoon around 3 PM it switched back to Storm Watch and is still in that mode on Wednesday at 6 AM. The interesting thing is that the storm has passed completely.

    The best thing is that the grid never went down. But then I did not get to test my powerwalls today. Oh Well...
  • I live in the middle of the Northern California fire zone. The StormWatch includes (and properly responds to) "red flag" fire alerts as well as public utility planned shutdowns as well as our local actual storms and flash flood warnings. My experience has been very good - almost too good in that the warning may be appropriate for a neighbor 5 miles away but not for my actual home. I would assess the performance as "better safe than sorry".
  • > @gregbrew_98470014 said:
    > Nope. Unless you live in Great Britain or Australia.
    > U.S. electrical utilities don't want the competition, and have very effective lobbyists.

    Solar support specialists for PG&E utility in northern California swear there is absolutely no prohibition on their side for charging from the grid, with or without PV on the system. I am currently waiting for Tesla to respond to that information and remove the grid charging restriction.
  • If you used the US solar tax rebate to pay for part of the PowerWalls, you will be restricted from grid charging.
  • I replied to that in a related thread. I don't believe the federal tax credit has any performance requirements at all. The California SGIP incentive specifies minimum levels of self generation over time. A believe a small amount of grid charging can help cut energy costs for my home while still meeting the SGIP requirements.
  • I need to make a correction to my previous statement. I said I didn't think there was a performance requirement for the federal tax credit. Technically that may be correct but the actual limitation is even more restrictive. To qualify for the federal tax credit, the batteries must be "charged exclusively" by solar. I don't like it but there it is.
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