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18 hour grid outage here, some new observations on system behavior

Discussion in 'Tesla Energy' started by nyprepper, Dec 3, 2019.

  1. nyprepper

    nyprepper Member

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    Western Orange County NY here..... we got slammed. Got about 1/4" of ice followed by 15" of snow followed by another 1/4" of ice. StormWatch was active since Sunday morning. The storm started Sunday afternoon.

    PW's were at 100% when we lost power at about noon yesterday (Monday). Heavy ice and snow covering panels so zero solar production. Grid came back up for about 2 hours from 6pm to 8pm before crashing again. StormWatch was still active when power came back on, and the PW's were promptly topped off from the grid! Took them from 84% back up to 100% very quickly. I noticed the 2 PW's were drawing 6.7kw during the charge.

    Grid is still down here since 8pm last night (going on 13 hours). PW's are at 81% capacity. I need to go outside and get on the ladder with the rubber rake to try and clean the panels. I think we could be off grid for another 24 hours judging from the looks of this mess.

    Very very very pleased with the way the system is performing. StormWatch really helped during the 2 hour period when the grid came back up by allowing the PW's to get topped off. We have had zero solar production since Sunday morning.
     
    • Like x 7
    • Informative x 5
    • Helpful x 1
  2. KY-Lonewolf

    KY-Lonewolf Supporting Member

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    Great news nyprepper! Glad to see things are working well. Keep us updated on your status.
    Be safe.
     
  3. gpez

    gpez Member

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    Very cool!

    Also really glad to hear anecdotal confirmation of the grid charging behavior while StormWatch is active and there is a brief grid restoration. When I was having my system put in this was a big open question that my installer did not have the answer for and seemed like it could be quite a critical problem if the Powerwall couldn't top off in exactly this situation. Neat to hear it's working like this! Stay warm and safe :)
     
  4. Dan123

    Dan123 Member

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    You probably don't need to clean the entire panel, it is usually enough to expose some of the black surface to get the melting process started. The dark panel gets heated quickly in the sun.
     
  5. ivan801

    ivan801 Member

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    This storm watch behavior may become an issue down the road: power comes back on, everyone starts charging their batteries back to full, grid fails because it gets overloaded.
     
  6. Rhodesman

    Rhodesman Member

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    Question, what's your average draw on the powerwalls? I have two but very rarely will I be 13 hours on powerwall power and only be down to 81%! Usually at that time I'm fishing the candles out of closets!
     
  7. nyprepper

    nyprepper Member

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    We got grid power back late last night....so about 25 hours straight running on the PW's with zero solar production due to ice and snow on the panels.

    When the grid came back up, my PW's were at about 60% remaining capacity. I was running basics only..... fridge, LED lights, internet, TV, well pump, and very light oil furnace usage (we heat mostly with wood but use the oil furnace for hot water). Running basics as described, I can get the house draw down to about .5KW (500 watts) on average.

    A couple of key observations in my situation:

    1) It would be really nice to be able to top the batteries back up off the grid.... at least once....immediately following a storm event (or, just leave StormWatch active for 24 hours following a weather event). The risk of another grid outage here is high right now and PW's are sitting at 60% reserve, still with zero solar production. Another option would be to allow PW charging from a backup generator.

    2) Snow preceded by ice followed by very cold temps makes it impossible to clear my panels. It would be really nice if they had an internal heating element that could be switched on in situations like mine. Based on my local forecast, I doubt the panels will thaw and clear within the next 5 days.

    3) I was prepared for the worst and ready to switch over to backup gas generator if grid power didn't come back soon. Even though PW's feed my main panel, I have a sub-panel setup for the generator with it's own transfer switch but I forgot the correct order of doing things....fortunately I know a Tesla electrician and was able to call him for Q&A. Very important order of things......first, switch off both powerwalls (switche on the units themselves), second, flip the outside breakers for both batteries in the outside panel (I have 2 circuits for each on panel off the utility meter outside). third, subpanel transfer switch...... and start genset.
     
    • Informative x 1
  8. aesculus

    aesculus Still Trying to Figure This All Out

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    You send send this comment to Tesla. I like the idea and feel it will be needed by me as well. I will also submit it.
     
  9. nyprepper

    nyprepper Member

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    well exactly what I feared has happened. was not able to clear my panels and the grid just went down again. zero solar production and starting this one with only 60% reserves. i might try the garden hose on the panels.... it's 34 degrees farenheit right now. rubber roof can't cut it.
     
  10. Dan123

    Dan123 Member

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    Can you put some deicer on them? Or some hot water?
     
  11. masam

    masam Member

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    Solar installers generally discourage using deicers. With hot water you have to be careful otherwise the temperature difference could potentially damage the panels. I've found this to e quite effective : Remove Snow From Solar Panels With the Snow Pro Soft Roof Rake
    For those looking to buy this, you can get an extension pole cheaper from Lowes (https://www.lowes.com/pd/Mr-LongArm-Pro-Lok-8-4-ft-to-23-2-ft-Telescoping-Threaded-Extension-Pole/4755038) and a foam head from Home Depot for less. Ive found that as along as you get the bottom edges clean, the sun helps with the rest. Lot of work though. :(
     
    • Like x 1
  12. nyprepper

    nyprepper Member

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    I have the same Snow Pro roof rake and telescoping pole. It generally works well with snow. Unfortunately, we got almost 1/2" of ice before the snow. And it's been very cold here ever since. I raked all the snow off my panels but there is still a thick layer of ice. It has now been 7 days here with zero solar production. Mon/Tue will be 50 degrees and raining here. Hopefully that will clear them off. This really is a weak spot in terms of system reliability for me.
     
  13. masam

    masam Member

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    @nyprepper - yeah, the ice really makes it much harder. I really wish there was an easy and cost effective way to clear the wet heavy snow (and ice) safely. I'm hoping the warmer weather and rain on Monday and Tuesday clean it up.
     
  14. charlesj

    charlesj Member

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    Life is a lot of work, yes. ;) :D
     

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