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Can Powerwall 2 operate in multimode at the same time?

Discussion in 'Tesla Energy' started by dutchinchicago, Nov 1, 2016.

  1. dutchinchicago

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    From the spec it shows that the PowerWall 2 supports the following modes:

    Solar self-consumption
    Time of use load shifting
    Backup
    Off grid

    I am hoping that the powerwall can do a combination of the above at the same time.

    I would like my powerwalls to charge to 70% overnight for "Time of use load shifting" then during the day I would like them to use that stored energy and do "Solar self-consumption". When I get a powercut I would like it to operate in "Backup" mode.

    Does anyone have any information if this is the way it works or are the modes exclusive?

    I ordered 2 powerwalls but might have to cancel if it can not do the modes in parallel.
     
  2. ecarfan

    ecarfan Well-Known Member

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    I'm not sure I understand your question. My Powerwall 1.0 does TOU load shifting and can also simultaneously function as a backup power source if the grid fails (meaning I am off grid). As far as "solar self consumption", when my panels are producing energy the power is sent to my main panel to power whatever loads are running and if my load is greater than the panel output at any given moment additional power is either drawn from the grid of from my battery. Excess solar production is first used to recharge the Powerwall and then if there is still excess it is sent to the grid.

    Does that answer your question?
     
  3. electracity

    electracity Active Member

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    When they get the software done, probably. But you made need to buy the AC powerwall to charge overnight from the grid. The DC Powerwall may only be chargeable from solar.

    The AC powerwall is likely the "do all" product that has an efficiency penalty compared to the DC product. The AC powerwall is likely intended to retrofit existing solar systems without inverter replacement. It should also work without solar.

    The DC powerwall is likely closer to powerwall 1.0, with perhaps a solar inverter included. The DC powerwall is likely intended for new solar installations.

    The first powerwalls shipped will likely perform only do a subset of the announced functionality.
     
  4. ecarfan

    ecarfan Well-Known Member

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    The Powerwall technical specs at Tesla Powerwall say nothing about the being a "DC Powerwall" and an "AC Powerwall".

    Please provide a source to support your assertion that there are two different kinds of Powerwalls. I am interested to learn more about these two different Tesla Energy products.
     
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  5. electracity

    electracity Active Member

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    You might have noticed that Tesla has broadened the addressable market with the new powerwall. Whether they do it with two products, an add-on AC to DC converter, or just include a ac dc converter with new solar installs I don't know.

    Powerwall 1.0 is not a retrofit product. Powerwall 2 has features to address both market segments. This means they can sell the powerwall to people with solar without requiring inverter replacement.
     
  6. masam

    masam Member

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    ecarfan: I have a follow up question - when the utility power is off and the powerwall is acting as the backup source and provided the panels are producing power, does the powerwall also get recharged simultaneously ?
     
  7. dutchinchicago

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    Thanks for your reply,. It sort of answers my question. What is not clear is that you say the Powerwall can do TOU load shifting but if the battery is filled to 100% overnight then if I over produce solar power at 8am the battery is already full and I can not store the additional energy I produce.

    Therefor I am hoping that I can fill the battery to 70% at night so that if my solar panels are over producing in the morning I still have room to store my excess energy.

    Is it possible to specify around what times it will charge the battery for TOU load shifting? I want to make sure that it does not charge the batteries at the same time as my car is being charged to avoid capacity charges.
     
  8. Ampster

    Ampster Member

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    #8 Ampster, Nov 26, 2016
    Last edited: Nov 26, 2016
    One type of load shifting can mean that you run your critical loads off the battery (100% full in the morning) and sell all your solar production to the grid at high TOU rates. Then you can charge your batteries overnight at super off peak rates. Gaming the system like that is inefficient and only works in a net metering situation. I don't know if the Powerwall can do that but my hybrid inverter can do it. To be clear, I am not selling power from the batteries through the inverter to the grid.
     
  9. ecarfan

    ecarfan Well-Known Member

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    What I see is that by late evening my Powerwall is down to the 30% lower limit that I have it set to. It charges up during the day when I am producing more power than I am using. That makes sense to me. I do not want to charge my battery at night during the cheapest rate period, that is when I charge my Teslas.
    No.
     
  10. Utahken

    Utahken Member

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    Hi Ecarfan,

    It is true. There is a DC and an AC powerwall. I called Tesla (and my Tesla Rep) and they confirmed. The DC powerwall will be compatible with the SolarEdge StorEdge inverter. The website only references the AC powerwall.
     
  11. FreeOfPge

    FreeOfPge Member

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    Does anyone have an answer to this question?
     
  12. ecarfan

    ecarfan Well-Known Member

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    Hi Ken: thanks for confirming! Now I need to better understand the differences between those two types of Powerwall.

    The DC Powerwall requires an external inverter? (Specifically the SolarEdge compatible model)

    The AC Powerwall has a built in inverter?

    Did you find out what the price difference is? Any differences in size?
     
  13. Parzival

    Parzival Member

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    Yes, provided there is energy surplus (e.g. the energy provided by solar is greater than the draw from the powerwalls.)

    Elon mentioned this during the reveal -- that with Solar and Powerwall you'd have essentially endless power backup with the grid down.
     
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  14. Nevetsyad

    Nevetsyad Member

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    As a SolarEdge 7600 inverter owner, I'm interested in the AC PowerWall 2, unless there's a large price gap. To connect the DC PowerWall 2 to my system, I'd need to upgrade to the powerwall version of the 7600, which is about $1,500. Then, I'd need an auto-relay, some power sensors and other random hardware connected to my system. Another $1,000 or more. I'd then be limited to the output of my invert, 7kW sustained.

    If I got the AC version, when the sun was out, I could power 13kW with the two inverters. I wouldn't need to upgrade my SolarEdge, so it would be cheaper.

    My only concern, what happens if the AC PowerWall 2 goes dead in the middle of the night during an extended outage? My inverter won't function unless it detects AC. Will there be a "jump start" button on the PowerWall that uses the reserver .5kWh to produce enough current to get solar up and producing again?
     
  15. MP3Mike

    MP3Mike Active Member

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    I don't think that is how it works. If you get the AC version your SolarEdge 7600 will continue to handle the solar panels/load to feed your house and recharge the PowerWalls. Though I guess the PowerWalls could supplement if you demand more than the solar can provide. So you could get 17.6kW total, with a peak of 21.6kW. (7.6kW from your Solar and 10kW from your 2 PowerWalls.)

    The down-side to the AC version is that there is more charging loss from taking the DC Solar converting it to AC and then converting it back to DC to charge the batteries.
     
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  16. Utahken

    Utahken Member

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    Yes, yes, no,dont know :)

    There is a price difference but he did not know what it was. I wouldn't expect a size difference... Just wouldn't populate the inverter.
     
  17. miimura

    miimura Active Member

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    Actually, I would expect the DC/DC converter to take a similar amount of space as the AC inverter.
     
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