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Does solar charge all of the Powerwalls when you have two gateways?

I just got my four Powerwalls installed!

A picture would be worth 1000 words, but here is my attempt :-)

I have the following:
- Two 200A main breakers (located in the garage)
- Two 200A Load Centers (located in the basement far from the garage)
- Two "Tesla Gateway 2". (located in the garage)
- Four Powerwalls connected to the Gateways (2 to each) (located in the garage)

The house is setup for who house backup.

Now the tricky part... I had solar installed 4 years ago and the solar system is connected with a 50A breaker in one of the 200A Load Centers in the basement.

If I loose power:
1) Will all four of the power walls get power from the solar?
-or-
2) Will only the leg that is connected to solar charge on solar?

I could easily test this by shutting the breakers off, but I heard that was not a good idea.

Thanks for your thoughts.

Comments

  • If there is not some sort of cross connect between the two load centers, then at the time of grid disconnect, the solar sounds like it is physically separated from one of your load centers (and gateway). Without a connection - no electrons from solar to a pair of batteries.
    In terms of testing - it is actually a very good idea to test so you can verify details in order to prove or disprove your suspicions. You will note numerous comments on many threads about periodic testing - monthly - quarterly...just to make sure that firmware updates have not somehow impacted your system.
    The main thing is to do it on a sunny day so that you have sufficient solar to power the the house as well as feed the PowerWalls. Plan on keeping the grid feed off for at least 30 minutes so that you can verify solar recovery (with most systems, the solar will go offline briefly during the disconnect). This is also your chance to walk the house and make sure all of your circuits are active and supported as well as look for any equipment that does not play well with slight frequency changes.
    Another reason to test is to understand just how long you can go without grid power and to help you plan emergency load management if the grid is lost unexpectedly.
  • When you trip the main breaker(s) to test your backup system (I recommend that, too), just be sure that active loads are kept to a reasonably low level. Opening a breaker when there's high levels of current flowing through it can lead to arcing across the contacts, which can deposit carbon on them, leading to a reduced effective life and/or increased resistance in the contacts. The same is true about closing them with a high load on them.

    Each Powerwall (PW) can source up to 5kW continuously and 7kW for a short duration. Those number would be doubled for each of your pairs of PWs. Motorized devices like refrigerator and air conditioner compressors can present very high instantaneous surge loads as the motor starts up. This shouldn't be a problem, as long as other loads don't add up to anything near 10kW on either pair of PWs when you open the main breaker.

    What you *don't* want to do is test your system by opening the main breaker while an EV is charging. I made that mistake once, as I *used to* leave my two EVs plugged in all of the time. My two PWs didn't like that one bit.
  • thanks for the comments!

    @Jones_lab_guy your comments aligns with my view of what the system would do. I may want to move some loads (e.g. the main refrigerator to the Load Center with the Solar so if I had an extended power outage the fridge would keep going for a much longer period of time.

    @gregbrew_98470014 I think your comments on breakers under load is probably why some have discouraged throwing the breakers.
  • Instead of moving loads, is it possible to split your solar feed into two circuits ? For example, if you have two inverters - put one on each load center. This would require some assistance from Tesla in order to get an additional CT monitor configured...but it would ensure that both load centers had some ability to be charged during an outage.
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