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Powerwall 2 Installs in Hawaii

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I ordered only one Powerwall with a 4kW system and Tesla just told me my Utility requires 2 Powerwalls. WTF?? I'm waiting for the why. I hate talking to a Tesla intermediate solar manager.

2 Powerwalls is total overkill for my household so would not be worth the extra $6.5K. I have an existing 7.5kW NEM.
 
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I ordered only one Powerwall with a 4kW system and Tesla just told me my Utility requires 2 Powerwalls. WTF?? I'm waiting for the why. I hate talking to a Tesla intermediate solar manager.

2 Powerwalls is total overkill for my household so would not be worth the extra $6.5K. I have an existing 7.5kW NEM.
If you will have a total of 4kW + 7.5kW of solar, you really do need two Powerwalls. They can only absorb 5kW of solar each. The only other option is to put the new 4kW solar outside the backup gateway so that it will remain off when the grid goes down. The system is not stable in island mode with your solar potentially overloading the Powerwalls.
 
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If you will have a total of 4kW + 7.5kW of solar, you really do need two Powerwalls. They can only absorb 5kW of solar each. The only other option is to put the new 4kW solar outside the backup gateway so that it will remain off when the grid goes down. The system is not stable in island mode with your solar potentially overloading the Powerwalls.

Something doesn't sound right. I have 2 PWs with a 5.25kW NEM system + 3.78 kW NEM+ system, but I was only going to put 1 PW originally and changed to 2 PW later during the planning phase, and the advisor that was helping me with planning said it was totally my choice how many PWs I want. I could have gone with 3 PWs too to get me to 100% off grid.
 
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Something doesn't sound right. I have 2 PWs with a 5.25kW NEM system + 3.78 kW NEM+ system, but I was only going to put 1 PW originally and changed to 2 PW later during the planning phase, and the advisor that was helping me with planning said it was totally my choice how many PWs I want. I could have gone with 3 PWs too to get me to 100% off grid.
More Powerwalls is rarely a problem until you get above 5. However, there are definitely downsides to having only one. I originally wanted only one but I'm super happy that I got two. The install is also more expensive for one, which seems counter-intuitive at first, but they usually have to divide up your household loads into a critical loads panel for partial backup when you only get one Powerwall.
 
If you will have a total of 4kW + 7.5kW of solar, you really do need two Powerwalls. They can only absorb 5kW of solar each. The only other option is to put the new 4kW solar outside the backup gateway so that it will remain off when the grid goes down. The system is not stable in island mode with your solar potentially overloading the Powerwalls.

Mahalo for the explanation. This is way better than the confusing explanation the Tesla advisor gave me.

Now to decide whether to have zero, one or two powerwalls to save less than $100 per month.
 
You need PWs for your neighbors. WHAT? Well, one PW might be enough for your needs. But you know how often our power goes out. You also gotta know how popular you are going to become when power goes out and your neighbor cousins drop in for a cell phone charge because they can't. And then once the phone is charged, they will be dragging extension cords from their house to yours to plug in their fridge. I mean after all, you do have a Tesla, so you have more than enough range and "juice" and you won't mind sharing. So, you need that second one for "cus'.
 
For the record, I'm in the camp where Tesla didn't take the photos required for HECO to proceed with meter installation/PTO. My timeline was probably slowed down by the fact that I sent a physical check to Tesla, but no action was taken until I contacted them regarding status. The key takeaway is to manage your own project as much as you can; don't wait for them to do things. Be the squeaky wheel!
 
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I was under the impression that a second system will not join an existing system for energy going into the Powerwall. Now when the grid goes out, will both systems load the Powerwall?
It is possible. However, I would make sure to bring up the issue as early as possible in the process because the placement of the required CTs (current transformers) to measure the both solar systems may not be so straight forward. A guy in Arizona had an old solar system, then added Powerwalls, then added more Tesla solar and the new solar did not charge his Powerwalls because the solar techs did not reconfigure the Powerwall CTs. If you are having new solar and Powerwalls installed at the same time, they should plan ahead for it.
 
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Let's see if they can fix it this time.
 

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Just to add a little data to the conversation, here's my solar timeline:

Original order: 6/9/20
Upgraded order to higher capacity panels: 6/26/20
Install Day: 9/9/20
City & County inspection: 11/16/20
PTO: 12/17/20

Things to keep in mind: I paid by check, which led to a 2-4 week delay between install and inspection; and I did not have the installation issues people like Casper702 had. It is not a quick process and requires active customer engagement to move the process along, especially if you run into equipment issues. You can't just wait for Tesla to take action; you have to be the somewhat annoying/nagging customer who won't shut up until they get it right!
 
When you talk to Tesla ask them for the Solaredge case number so you can track the replacement invertor with Solaredge.

For over a month Tesla lied to me daily saying the inverter wasn't delivered because Solar edge hasn't shipped it. After I was able to get delivery confirmation from Solaredge and send it to Tesla they finally came out to replace my inverter.
 
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