My rep also called. When he identified himself as the Solar City Rep I thought for sure he was calling to reschedule my installation to sometime next spring like some other folks have been complaining about. But to my surprise he only had to reschedule the Main Panel Upgrade. Installation still good to go in a couple of weeks. We had 5 outages in 6 months lasting all day due to maintenance.
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Powerwall 2: Installation
- Thread starter JeffreyY
- Start date
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- Powerwall Tesla Energy
This morning the Tesla installer who will be installing my Powerwalls stopped by unannounced this morning while I was out to check out the site for my installation. NO biggie, but if he had called ahead, I would have been around to talk to him about the installation. Looks like it is still on for Monday 12/18.
Tesla is finally here doing the install. According to the crew I am only the second installation in the San Bernardino mountains, the first being a customer in Lake Arrowhead who had three batteries installed. I will post pictures and details of my installation later.
My solar and powerwalls have been up and running for about a week now. Everything has gone pretty smoothly. I purchased direct from SolarCity and there have only been a few hiccups:
1) They didn't get the SGIP app with SDG&E in on time to attempt to qualify for Tier 1...but I was awarded Tier 2 so overall, I'm still pretty psyched about it
2) On installation day, they felt they couldn't safely install the two panels on the 3rd floor roof, which is by far the best (although smallest) mount plane of all the 19 panels I had installed (due south, no obstructions, low angle). On the plus side, they were able to move them elsewhere even though the design team had told me there was no way to get additional panels on the roof. The new location is still west facing, so given how TOU rate schedules are changing, it isn't a terrible thing. So, some good, some bad on that front.
3) I signed the agreement in April...and the install happened in December. They had set an expectation of 2-3 months after signing the contract, so that was a bit of a miss.
I'm working with them now to try to get those two additional panels on the 3rd floor mounting location. They said the primary issue was that there was no permanent/solid ground at the only access point to that roof -- it's just dirt right now since my landscaping isn't installed yet. So, that seems understandable, but it feels like that should have been noted to me by the design team that put it together since they were out here and even specified where the ladder access to the 3rd floor was on the design plan (for the installers presumably). I'm also wondering why they said they couldn't fit panels in the location they ended up installing them...I would have paid for those in a heartbeat.
I have offered to pay for the 2 panels to be added into the original third floor location since I wanted more anyway, and while it is clear they would prefer I don't pursue it, they have agreed to work up a modified contract so that I can decide if it makes sense to pursue it. We'll see how it turns out -- apparently I will need a larger inverter and potentially some other alterations to make it happen. I'll also have to find a way to satisfy their safety concerns before they return for the install.
Does anyone know if there are limitations on what rate plans I can adopt having both solar, power walls, and an EV? Can I still sign up for one of the EV plans (SDG&E)? Is that still generally the best rate plan for people in my situation? I'm trying to make sense of the plans and it seems like the EV plan probably is since nearly all of my usage beyond what I generate is charging the car (and I'll be running the pool mostly super-off-peak as well once that is installed).
I don't see any real difference between TOU-EV and TOU-EV-2...does anyone know the difference?
Given the TOU rate periods, the battery seems to make a ton of sense. I don't have nearly enough solar to fulfill my daily needs due to the Model S but it does pretty much power the house and fill the battery enough that the batteries supply electricity through peak time.
1) They didn't get the SGIP app with SDG&E in on time to attempt to qualify for Tier 1...but I was awarded Tier 2 so overall, I'm still pretty psyched about it
2) On installation day, they felt they couldn't safely install the two panels on the 3rd floor roof, which is by far the best (although smallest) mount plane of all the 19 panels I had installed (due south, no obstructions, low angle). On the plus side, they were able to move them elsewhere even though the design team had told me there was no way to get additional panels on the roof. The new location is still west facing, so given how TOU rate schedules are changing, it isn't a terrible thing. So, some good, some bad on that front.
3) I signed the agreement in April...and the install happened in December. They had set an expectation of 2-3 months after signing the contract, so that was a bit of a miss.
I'm working with them now to try to get those two additional panels on the 3rd floor mounting location. They said the primary issue was that there was no permanent/solid ground at the only access point to that roof -- it's just dirt right now since my landscaping isn't installed yet. So, that seems understandable, but it feels like that should have been noted to me by the design team that put it together since they were out here and even specified where the ladder access to the 3rd floor was on the design plan (for the installers presumably). I'm also wondering why they said they couldn't fit panels in the location they ended up installing them...I would have paid for those in a heartbeat.
I have offered to pay for the 2 panels to be added into the original third floor location since I wanted more anyway, and while it is clear they would prefer I don't pursue it, they have agreed to work up a modified contract so that I can decide if it makes sense to pursue it. We'll see how it turns out -- apparently I will need a larger inverter and potentially some other alterations to make it happen. I'll also have to find a way to satisfy their safety concerns before they return for the install.
Does anyone know if there are limitations on what rate plans I can adopt having both solar, power walls, and an EV? Can I still sign up for one of the EV plans (SDG&E)? Is that still generally the best rate plan for people in my situation? I'm trying to make sense of the plans and it seems like the EV plan probably is since nearly all of my usage beyond what I generate is charging the car (and I'll be running the pool mostly super-off-peak as well once that is installed).
I don't see any real difference between TOU-EV and TOU-EV-2...does anyone know the difference?
Given the TOU rate periods, the battery seems to make a ton of sense. I don't have nearly enough solar to fulfill my daily needs due to the Model S but it does pretty much power the house and fill the battery enough that the batteries supply electricity through peak time.
The difference between EV-TOU and EV-TOU2 is that EV-TOU2 applies to your whole house, while EV-TOU applies to just your car (and requires installing a second meter at your expense).
Is this related to initial install or future serviceability? An electric articulated tow behind lift (or boom lift, but that is more cost/ hassle) might provide access. Can even tow the lift with an X.
The initial install.
Doesn't seem like a tow/boom lift would be realistic -- I don't have a way to get that equipment to my backyard which is the only place with access to the 3rd floor roof.
We'll see what happens. The latest is that there is a massive time crunch because the only outstanding thing holding up completion of the project is SDG&E approval for turn on and my Tesla rep said that if they give that, we won't be able to make any changes to the contract after that...so, somehow, they have to get the updated design and pricing completed, I apparently will have to provide proof that there is a solid surface for the ladder, and we have to actually both agree to the modifications...all before permission to turn on happens, which could be any day now.
Naturally, it's the holidays and my rep's father-in-law just passed away so I don't give any of this much chance of ending with me being thrilled with the outcome.
It feels like I'm going to end up eating their mistake and my best roof won't have any panels on it.
philgrocks
Member
Hi everyone. I read thru this whole thread hoping I could find questions already answered.
1) Power wall install
- I have 400A service to my house. Comes in next to the Garage and then splits into two 200A services runs that go several hundred feet to the basement of the house where there are two 200A subpanels
- On one of the 200A subpanels I have solar installed. 50A breaker for my 10KW solar system.
- The solar system interconnect is on the side of the house with its own disconnect and sub-panel (so also very far from where 400A service comes)
- Looking over the information I can find it seems that the power wall units would be located near the solar system interconnect and they would be connected there. Back feeding power to one 200A sub-panel.
- Is that right?
2) So what about the gateway?
- It seems the gateway does a few things... Measuring your power and doing the mains disconnect when there is a power failure.
- Based on the above assumption it would need to be located at the main breaker.
- Is that right?
3) I presume the gateway communicates to the Powerwall over Power line. Running a network wire between these two would be impossible.
4) Lastly I am on the California EVA rate plan. I put in as big of a solar system as my roof would allow (panels pointing, east, west, and south!... But still I don’t generate enough power :-(. So it would make sense to charge up the Powerwall some during off peak hours. Does the app allow for this? Is it scheduled?
Thanks everyone for your help and sorry if I missed these details if they are posted someplace else.
Best
Phil
1) Power wall install
- I have 400A service to my house. Comes in next to the Garage and then splits into two 200A services runs that go several hundred feet to the basement of the house where there are two 200A subpanels
- On one of the 200A subpanels I have solar installed. 50A breaker for my 10KW solar system.
- The solar system interconnect is on the side of the house with its own disconnect and sub-panel (so also very far from where 400A service comes)
- Looking over the information I can find it seems that the power wall units would be located near the solar system interconnect and they would be connected there. Back feeding power to one 200A sub-panel.
- Is that right?
2) So what about the gateway?
- It seems the gateway does a few things... Measuring your power and doing the mains disconnect when there is a power failure.
- Based on the above assumption it would need to be located at the main breaker.
- Is that right?
3) I presume the gateway communicates to the Powerwall over Power line. Running a network wire between these two would be impossible.
4) Lastly I am on the California EVA rate plan. I put in as big of a solar system as my roof would allow (panels pointing, east, west, and south!... But still I don’t generate enough power :-(. So it would make sense to charge up the Powerwall some during off peak hours. Does the app allow for this? Is it scheduled?
Thanks everyone for your help and sorry if I missed these details if they are posted someplace else.
Best
Phil
So there should be a panel next to the meter (outside the garage or just inside the garage behind the meter) with two 200A double pole breakers in it. Is that correct?
The Powerwalls can be connected to your electrical system anywhere behind the Backup Gateway. Proximity to the solar equipment is not required.
No, the gateway can also be anywhere in the electrical system. Any loads behind the gateway get backup power, and any other loads would not get backup power. The current Backup Gateway is rated for a maximum of 200A.
The simplest solution for your situation would be to put all your "critical loads" in the 200A panel that has the solar 50A breaker, and then put the Backup Gateway somewhere on the feeder from the service entrance to that 200A panel. The loads on your other 200A panel would not be backed up.
A complete one-line diagram of your electrical system would be required to give a definite answer on your design. Portions of the electrical system that can get power from multiple sources are subject to various rules to ensure they are properly protected from overload. That can complicate the design and require additional panels to be installed in conjunction with the Backup Gateway.
If you want to backup both 200A panels, then you'd need to wait for a 400A rated Backup Gateway, or install two separate systems.
I believe it is Ethernet, but perhaps Teslas supplies Powerline Ethernet adapters if required? Not sure on this one.
Cheers, Wayne
Hi,
Assuming we are talking the AC Powerwalls. Users manual is available on-line.
I assume your meter is unfused with double output lugs to the sub-panels. (My current set up)
The gateway is rated for 200A, so you'll need to pick a sub panel to backup with the Powerwall, or use two gateways and separate PWs for each panel.
The Powerwalls would connect directly to the panel via a back fed breaker. They can mount by the gateway/ panel.
Communication used to be 5 wire CAN (from the original install manual), but since they co-mount, not an issue.
Not sure if PW supports TOU shifting currently.
Unfused conductors (service conductors, which are the wires between the meter and the service disconnect, the first circuit breaker) aren't allowed to travel through the interior of a building. The service disconnect has to be outside, or inside right where the service conductors enter the building.
Cheers, Wayne
Right, and with the several hundred foot run to the basement, I assumed it was all external. Could have two 200A disconnects at the garage/ meter. Or dual 200A mobile home panels with feed throughs and garage load breakers. Or a 400A panel with 200A breakers, or ....
philgrocks
Member
Thanks very much for your help.
Yes there are two 200A double pole breakers.
I figured the gateway was rated @ 200A.
It would be OK to have just 1/2 the house on backup power, we don't loose power too often.
philgrocks
Member
philgrocks
Member
Yes, that diagram makes it clear. If you use only one line instead of your double red/blue lines, that would be the one-line diagram I referred to. I think a single line would be clearer. (And if you want to show each conductor, you'd need 3 instead of 2, two hots and the neutral).Perhaps his diagram will make it more clear. I have a complicated setup
Are both 200A subpanels in the basement? Because you show one feeding a garage subpanel, so if it's in the basement the power goes from the meter on the garage to the basement back to the garage, which seems roundabout.
Anyway, the complexity is the 120% rule you referred to in explaining why one of your 200A breakers was downgraded to 175A when a 50A breaker was put in the corresponding panel to backfeed your solar. [200A + 50A > 120% * 200A, but 175A + 50A < 120% * 200A.] The same thing applies to the breakers from the Powerwalls, which would be 30A per unit. If you want to be able to charge the Powerwalls from solar during a blackout (e.g. after a big earthquake), then I think you might need 3 Powerwalls (or possibly 2 Powerwalls if your solar can be easily split up into two sources on two separate breakers, e.g. if you have two string inverters). The full specs on your solar system would be required to determine the minimum number of Powerwalls for off-grid solar charging.
A relatively easy way to install a system with a single Backup Gateway for you would be to set the Backup Gateway next to the subpanel with the 175A feeder. Then you'd need a new 200A panel that would get the existing 50A breaker from the solar and one or more 30A breakers from the Powerwall(s) (maximum 5). The Backup Gateway has double lugs on its load side, so it would be fed by the existing feeder coming from the service entrance, and then two new 200A feeders would be installed, one to the new 200A panel, and one to your existing 200A subpanel that had the 50A breaker in it. This last feeder needs to land on a main breaker in a panel (not a main lug only panel), so if that panel doesn't have a main breaker, you'd either need to add one to it, or add a 200A disconnect (enclosed circuit breaker) between the Backup Gateway and that existing subpanel. [The reason for this is to ensure that the loads in the subpanel don't draw more than 200A and overload the new 200A feeder or the 200A bus in the panel, since this panel would now be able to draw power both from the grid and from the solar/Powerwalls.]
Sorry if this post isn't organized well, just ask if you have questions. I'm a little too lazy to draw up a one line diagram of the above. : - )
Cheers, Wayne
philgrocks
Member
@wwhitney right on simplification. Attached
Both sub-panels are in the basement
I'm using sunpower micro inverter panels. So I would need to reconfigure the system :-( to split between the two sub panels. That would be hard.
Your right on the money for why the break was changed with regards to the 120% rule. I had concerns with doing this, but it has been OK.
I can't upload the PPT file :-(
So if I have Solar and Power wall on the same sub panel. A 10KW solar systems needs a 50A breaker and you say each power wall needs a 30A breaker. Say I have two power walls... I would need two 30A beakers. But Solar + 2 power walls wouldn't that mean I would have to downgrade the main breaker further? 50A+30A+30A = 110A, the main breaker would have to downgraded a bunch more.
Solar only config: 175A+50A = 225 (less than 120% of 200A which is 240A)
But Solar + power wall 175A+50+30+30 = 285. So I would need to downgrade main breaker again to 130A! That seems problematic.
Both sub-panels are in the basement
I'm using sunpower micro inverter panels. So I would need to reconfigure the system :-( to split between the two sub panels. That would be hard.
Your right on the money for why the break was changed with regards to the 120% rule. I had concerns with doing this, but it has been OK.
I can't upload the PPT file :-(
So if I have Solar and Power wall on the same sub panel. A 10KW solar systems needs a 50A breaker and you say each power wall needs a 30A breaker. Say I have two power walls... I would need two 30A beakers. But Solar + 2 power walls wouldn't that mean I would have to downgrade the main breaker further? 50A+30A+30A = 110A, the main breaker would have to downgraded a bunch more.
Solar only config: 175A+50A = 225 (less than 120% of 200A which is 240A)
But Solar + power wall 175A+50+30+30 = 285. So I would need to downgrade main breaker again to 130A! That seems problematic.
Not sure what you're trying to upload or why it won't work, but if it is a filename extension filter on teslamotorsclub.com you could change the file name and upload it in a post that says to use it you have to download it and change the filename extension.
Do the two 200A subpanels have main breakers in them? It looks like they don't, but some panels put the main breaker on the upper right or upper left, rather than above all the load breakers.
The reason your service disconnect main breaker had to be downgraded from 200A to 175A is because your current arrangement feeds the power from the solar panels into the same bus that is fed by the POCO (power company). To do that you have to ensure the bus is protected by one of several measures, the typical one of which is that you place the two different feeds at opposite ends of the bus, and then you can feed up to 120% of the bus rating.
An alternative would have been to replace that panel with a 225A bus. Then 200A + 50A < 120% * 225A. That would have been a lot more work, though, and in practice it is unlikely that 200A panel sees anywhere near 175A.
As you figured out, if you try to feed the Powerwall power into the same panel housing your 50A solar breaker, it will be problematic to properly protect that panel's bus. However, if you draw out the one-line diagram that I described, you will see that your 200A subpanel is no longer fed from more than one source, it is just fed from the 200A feeder from the Backup Gateway. In fact, the 175A breaker in the service disconnect could be changed back to 200A. However, that 200A load panel fed from the Backup Gateway will require a main breaker in it (or in a separate enclosure in front of it). That is actually to protect the 200A feeder from the Backup Gateway to the 200A load panel, since now that feeder is now fed from more than one source (the solar/Powerwall panel and the POCO).
Anyway, these details are something you'd have to work out with your installer. The upshot is that the best place to put the Backup Gateway and the Powerwall units is next to the panel currently fed by the 175A breaker and with the 50A solar breaker in it.
Cheers, Wayne
@wwhitney @philgrocks
Agree with everything Wayne said, it is a minimal impact way of getting the PW connected.
I'm going to approach from the tear up side of things with a focus on backup capability.
You have a lot of loads that can be shed during an outage, but they are distributed to both panels. To make the overall system work automatically, either the loads need to swap panels so that one has all the criticals (and less load than the system can provide), or cut outs need added to inhibit the large ones. Wayne, do you know if the gateway has an accessible status signal?
A potential overall issue is that your current panels are mostly full (all populated, but there are 2 doubles turned off and 4 other spots not labled). Depending whether the panel allows duplex breakers (or adding a subpanel), that can be worked around. (Wayne's setup avoids that issue). A complicating issue with change is the Arc Fault requirement which may kick in if you modify things (unless you currently have AFCI outlets).
The tear up plan:
Move your backup loads to the left/ solar panel.
Change the 175 service breaker back to 200A.
Place a 200A mobile home feeder panel in the garage between the meter disconnect and the left panel feed. PW0816B1200TC or similar.
In the mobile home panel, put the 70A pool breaker and 50A EV circuits from the garage load box. Install filler plates to cover holes. (It may also make sense to move the other EV load panel here based on final panel load calculations)
Locate the gateway near the left panel in the feed path to the panel.
In the left panel, downsize the garage feed breaker based on new loading, connect PWs, and add a new main breaker rated for the solar/ PW back feed.
This reduces the loading on the left panel to match new main breaker and gives you backup for both the house and garage circuits. If you need even more flexibility, there is a manual generator interlock kit for the mobile home panel. With this, you could place another panel in the feed for the right panel and then manually turn off the large loads and switch to backup power fed from the left panel. Can also use it to connect a portable generator.
Wayne, please correct if I miswired.
Agree with everything Wayne said, it is a minimal impact way of getting the PW connected.
I'm going to approach from the tear up side of things with a focus on backup capability.
You have a lot of loads that can be shed during an outage, but they are distributed to both panels. To make the overall system work automatically, either the loads need to swap panels so that one has all the criticals (and less load than the system can provide), or cut outs need added to inhibit the large ones. Wayne, do you know if the gateway has an accessible status signal?
A potential overall issue is that your current panels are mostly full (all populated, but there are 2 doubles turned off and 4 other spots not labled). Depending whether the panel allows duplex breakers (or adding a subpanel), that can be worked around. (Wayne's setup avoids that issue). A complicating issue with change is the Arc Fault requirement which may kick in if you modify things (unless you currently have AFCI outlets).
The tear up plan:
Move your backup loads to the left/ solar panel.
Change the 175 service breaker back to 200A.
Place a 200A mobile home feeder panel in the garage between the meter disconnect and the left panel feed. PW0816B1200TC or similar.
In the mobile home panel, put the 70A pool breaker and 50A EV circuits from the garage load box. Install filler plates to cover holes. (It may also make sense to move the other EV load panel here based on final panel load calculations)
Locate the gateway near the left panel in the feed path to the panel.
In the left panel, downsize the garage feed breaker based on new loading, connect PWs, and add a new main breaker rated for the solar/ PW back feed.
This reduces the loading on the left panel to match new main breaker and gives you backup for both the house and garage circuits. If you need even more flexibility, there is a manual generator interlock kit for the mobile home panel. With this, you could place another panel in the feed for the right panel and then manually turn off the large loads and switch to backup power fed from the left panel. Can also use it to connect a portable generator.
Wayne, please correct if I miswired.
