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Main Panel Upgrade After Solar Panel and Powerwall Installation

PG&E said it would cost about $40k for them to do the trenching from across the street to my main panel!
Independent contractor would cost about $28k ($20k trenching + $8k PG&E fees) which is still a crazy amount to me.
The PG&E costs sound about right but this is a bigger price difference than I saw. Most contractors were happy to take my money but they all recommended that I actually use PG&E because the crews to do all the work show up together and there is less disruption if you are in the house.
I'm not sure if PG&E will need to upgrade the transformer that feeds my block. I'm assuming if they did, it'd take them a long time to do so.
They would need to file city permits for this but that will not be the long pole. I heard from PG&E most of Q4 construction has been moved to next year. Maybe because of budget constraints?
People must have upgraded their main panels after Tesla installed solar. How did these people handle the change? Did Tesla come back out or did they have to hire independent solar company or electrician to replace the electrical lines?
I would love to hear about this too. I am pushing out my Tesla solar + PW install because of this reason.
 
If I have 100A panel, do you know if the electrical lines they install from the gateway to the solar panels and Powerwalls can handle 200A service? If I upgrade my panel later I wouldn't want to have to replace those electrical lines.
By default they would not. If you specify that you want all 200A feeder installed, it is possible to do. Whether Tesla is flexible enough to do it is unknown to me.

People must have upgraded their main panels after Tesla installed solar. How did these people handle the change? Did Tesla come back out or did they have to hire independent solar company or electrician to replace the electrical lines?
In theory any knowledgeable electrician could modify the system. In practice it may be hard to find someone other than Tesla that wants to deal with it.

Cheers, Wayne
 
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No 100A panel will be able to accommodate 200A wiring.
If the lugs for a 100A panel or breaker aren't able to accommodate the wire size required for a 200A feeder, then it's fine to reduce the wire size at the termination. Of course, that will require an extra connection, and take up more space in the panel, particularly when leaving the 200A feeder long enough for the planned 200A panel upgrade. So if the feeder length is, say, 10', probably not worth the attempt at future proofing, vs say 100'.

Cheers, Wayne
 
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If the lugs for a 100A panel or breaker aren't able to accommodate the wire size required for a 200A feeder, then it's fine to reduce the wire size at the termination. Of course, that will require an extra connection, and take up more space in the panel, particularly when leaving the 200A feeder long enough for the planned 200A panel upgrade. So if the feeder length is, say, 10', probably not worth the attempt at future proofing, vs say 100'.

Cheers, Wayne

Are the electrical lines from the Tesla Gateway to the solar panels and Powerwalls the same whether I have a 100A panel vs. a 400A panel (320A service split into 200A/120A breakers)? Would the only difference be the line between the main panel and the Tesla Gateway?

I understand it's better to install solar panels after the panel upgrade but it would probably delay the project 6+ months due to trenching and PG&E inspections. My ADU is pretty much complete and the city won't approve final inspection until I have solar installed. Also, I just found out my neighbor is also interested in upgrading his panel so depending on whether PG&E allows us to use the same trench, we might be able to split the cost of trenching across the street. But neighbor still needs to open up a project with PG&E for design and that will take 4-6 months.

Some have said it's really expensive to upgrade the panel after solar has been installed but how much are we talking about?
I would think many people with solar upgrade their panels after the fact especially if they decide they want to install EV charging.

Thoughts? Thanks!
 
Are the electrical lines from the Tesla Gateway to the solar panels and Powerwalls the same whether I have a 100A panel vs. a 400A panel (320A service split into 200A/120A breakers)? Would the only difference be the line between the main panel and the Tesla Gateway?
Yes on the first question. On the second question, yes plus the feeder to the backed up loads (and possibly non-backed up loads) panel(s).

Cheers, Wayne
 
I don't have great insights for you, however, I do have questions because I've wanted to ask someone who actually got PG&E to do a underground line upgrade.

My understanding is you pay an engineering fee to PG&E and then they determine what is needed to upgrade. That fee gets applied to their work if you go ahead and is lost if you don't. Is that correct?
 

jjrandorin

Moderator, Model 3, Tesla Energy Forums
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Nov 28, 2018
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Riverside Co. CA
People must have upgraded their main panels after Tesla installed solar. How did these people handle the change? Did Tesla come back out or did they have to hire independent solar company or electrician to replace the electrical lines?

Tesla isnt in the "regular electrical service" business, so I doubt very very very (very very very) seriously that they will be interested in the slightest at coming back out to do any work on your electrical, after they install your solar.

You will be dealing with some independent company for that work.
 
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PG&E said it would cost about $40k for them to do the trenching from across the street to my main panel!
Independent contractor would cost about $28k ($20k trenching + $8k PG&E fees) which is still a crazy amount to me.

*sigh* Do you have an "all in" budgetary number yet? I mean is the $40k with PG&E all costs, or are there more costs on top of that (setting aside the Tesla questions here).

If I have 100A panel, I'm assuming they'll run a 100A electric line from the 100A main panel to the Tesla gateway. I'm hoping I'd only have to replace the electrical line from the main panel to the gateway when I upgrade to a 400A panel and not all the electrical lines after the gateway.
Tesla Solar did NOT do my install, but I do have Powerwalls.

I ended up with a generation panel on the outside of my house just next to the main panel/meter. My main panel is only just the meter plus a single 100A breaker. That line goes in to the Tesla Gateway which is on the other side of the wall in the garage. Then it goes out of the Tesla Gateway into the generation panel. The 2 30A breakers from my Powerwalls plus the 3 20A breakers from my solar (and the single 15A breaker for my monitoring) all are in there. Then a 100A line goes out from the generation panel to my Span subpanel (which is where all the actual load circuits are).

People must have upgraded their main panels after Tesla installed solar. How did these people handle the change? Did Tesla come back out or did they have to hire independent solar company or electrician to replace the electrical lines?

They have, but it kind of depends on what you'd want to do. I'd only be going to 200A (no space for an ADU) so I'd probably just need to upgrade the small bit of wire from the main breaker to the Gateway and then the line from the generation panel to my subpanel along with any breakers.

In YOUR case, if you're going to 400A it depends on how you'd want that power "carved up" I guess.
 
*sigh* Do you have an "all in" budgetary number yet? I mean is the $40k with PG&E all costs, or are there more costs on top of that (setting aside the Tesla questions here).


Tesla Solar did NOT do my install, but I do have Powerwalls.

I ended up with a generation panel on the outside of my house just next to the main panel/meter. My main panel is only just the meter plus a single 100A breaker. That line goes in to the Tesla Gateway which is on the other side of the wall in the garage. Then it goes out of the Tesla Gateway into the generation panel. The 2 30A breakers from my Powerwalls plus the 3 20A breakers from my solar (and the single 15A breaker for my monitoring) all are in there. Then a 100A line goes out from the generation panel to my Span subpanel (which is where all the actual load circuits are).



They have, but it kind of depends on what you'd want to do. I'd only be going to 200A (no space for an ADU) so I'd probably just need to upgrade the small bit of wire from the main breaker to the Gateway and then the line from the generation panel to my subpanel along with any breakers.

In YOUR case, if you're going to 400A it depends on how you'd want that power "carved up" I guess.
It's a 400A panel but will be 320A service (I plan on splitting into a 200A breaker and 120A breaker (assuming they make a 120A breaker?). My electrician said that's the max PG&E would provide for residential. The 200A breaker would be connected to Tesla Gateway, powerwalls, solar panels. The other breaker will eventually be used for EV charger.

On top of the trenching fees, you'll need to pay electrician to install the new panel. In my case, it will involve relocating the wires from existing location because the new panels need to be more than 3ft away from the gas riser.
 
Tesla isnt in the "regular electrical service" business, so I doubt very very very (very very very) seriously that they will be interested in the slightest at coming back out to do any work on your electrical, after they install your solar.

You will be dealing with some independent company for that work.
That makes sense. But if I wait until my neighbor's ready to trench for his main panel upgrade, ideally we'd be able to split the cost of the trenching. I also asked trenching contractor if he would offer multi-customer discount if he did both trenching jobs and he said yes. I'm guessing I can save $5-7K for splitting the trenching. If it cost less than that to upgrade the electrical wiring from the main panel to the Tesla Gateway (after solar installation) then it would make sense to install solar now rather than waiting for underground trenching & main panel upgrade (which could take another 6 months to a year.
 

jjrandorin

Moderator, Model 3, Tesla Energy Forums
Moderator
Nov 28, 2018
17,496
23,440
Riverside Co. CA
That makes sense. But if I wait until my neighbor's ready to trench for his main panel upgrade, ideally we'd be able to split the cost of the trenching. I also asked trenching contractor if he would offer multi-customer discount if he did both trenching jobs and he said yes. I'm guessing I can save $5-7K for splitting the trenching. If it cost less than that to upgrade the electrical wiring from the main panel to the Tesla Gateway (after solar installation) then it would make sense to install solar now rather than waiting for underground trenching & main panel upgrade (which could take another 6 months to a year.

I hear everything you are saying, and realize you have all sorts of good reasons for saying it. My own personal opinion has not changed from what I posted in post number 8, however. its not my project or my money, and I am not an insider.

I am sure, given enough money, you will be able to work through just about anything. I still have the same opinion I posted earlier, but I am also not the one spending the money.

I hope it works out for you the way you want it to.
 
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It's a 400A panel but will be 320A service (I plan on splitting into a 200A breaker and 120A breaker (assuming they make a 120A breaker?). My electrician said that's the max PG&E would provide for residential. The 200A breaker would be connected to Tesla Gateway, powerwalls, solar panels. The other breaker will eventually be used for EV charger.

On top of the trenching fees, you'll need to pay electrician to install the new panel. In my case, it will involve relocating the wires from existing location because the new panels need to be more than 3ft away from the gas riser.

I shouldn't need a new panel, other than the main panel. All modern panels are rated for at least 200A.
 
It's a 400A panel but will be 320A service (I plan on splitting into a 200A breaker and 120A breaker (assuming they make a 120A breaker?). My electrician said that's the max PG&E would provide for residential. The 200A breaker would be connected to Tesla Gateway, powerwalls, solar panels. The other breaker will eventually be used for EV charger.

On top of the trenching fees, you'll need to pay electrician to install the new panel. In my case, it will involve relocating the wires from existing location because the new panels need to be more than 3ft away from the gas riser.
320A service conductors and a 400A service panel are part of the same thing usually "400A service on my house". We are getting into nuances here that aren't layman terms.

Typically services are rated to deliver 80% of the main breaker size continuously. So 320A* 1.25 = 400A

They do not make 120A breakers 125A is the closest. Likely when you buy your 400A service panel it will have 2x200 main breakers in it and that is preferred for a Tesla Powerwall system.
 
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You do not (repeat do not) want to be doing "anything" major to your home electrical, AFTER getting solar and powerwalls. No one will want to touch anything. Tesla isnt in the business of providing electrical modifications to your system after install, only supporting what they installed.

One reason I didn't have Tesla do the install. :)

In my case it's not *that* complicated. If I went to 200A it would be replacing the short run from the main to the gateway and the longer run from the generation panel to the sub. Replace a few breakers and done.
So, either "difficult and more expensive" than now, or "virtually impossible". Do all your upgrades first, and make PV / batteries last.

That's probably idea, but the world isn't often ideal. Getting PG&Es attention on a buried service upgrade is next to impossible. One reason I went with a Span panel and also the reason I'm reluctant to ditch my gas appliances.
 
Yes what people call a “panel” is more appropriately called a load center.
My "main panel" is this tiny little box next to the meter with a single 100A breaker in it. So sad.

My load center is where the actual home circuits are, and that's inside the garage.
I don’t know why you’d need to trench twice (or why you’d need 400A in the future). Can’t you install conduit to just pull the right wire later?

I wish I had conduit so bad...I hate my buried aluminum wire.
Typically services are rated to deliver 80% of the main breaker size continuously. So 320A* 1.25 = 400A

That's also why a 48A EVSE takes a 60A breaker.

They do not make 120A breakers 125A is the closest. Likely when you buy your 400A service panel it will have 2x200 main breakers in it and that is preferred for a Tesla Powerwall system.

If I was doing 2x200 I almost think I'd rather isolate them, especially if one is for charging. Separate meters, etc. But I'd be happy just going from 100A to 200A.
 
One reason I didn't have Tesla do the install. :)

In my case it's not *that* complicated. If I went to 200A it would be replacing the short run from the main to the gateway and the longer run from the generation panel to the sub. Replace a few breakers and done.


That's probably idea, but the world isn't often ideal. Getting PG&Es attention on a buried service upgrade is next to impossible. One reason I went with a Span panel and also the reason I'm reluctant to ditch my gas appliances.
Be glad you don't live in CPAU territory. They are now pushing any customer with more than 2 Powerwalls and 10 kW of PV into a customer-funded transformer upgrade.

Service upgrades in general are pretty disruptive and there will be lots of variation in costs.
I shouldn't need a new panel, other than the main panel. All modern panels are rated for at least 200A.
Certainly not true, both 100A and 125A are common sizes for subpanels and we often use smaller units to make the least impact on a customer's wall as possible.
 
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That's not correct. Panels with 200A busbars are probably the most common, but you can get them with 30A and up ratings.
Sorry, should have said "most". Or "all the ones I saw at home depot". If there was an edit button I'd change it.

Be glad you don't live in CPAU territory. They are now pushing any customer with more than 2 Powerwalls and 10 kW of PV into a customer-funded transformer upgrade.

If I could afford a house in Palo Alto I'd have, in some ways, fewer problems. At once point PG&E wasn't charging for service upgrades if it was for EV charging. I think the state is going to have to step in if they want us all to charge at home.
 
Sorry, should have said "most". Or "all the ones I saw at home depot". If there was an edit button I'd change it.



If I could afford a house in Palo Alto I'd have, in some ways, fewer problems. At once point PG&E wasn't charging for service upgrades if it was for EV charging. I think the state is going to have to step in if they want us all to charge at home.
IKR, most are much nicer than mine. The power prices are pretty low too, so that's really nice. Only SVP power is cheaper locally I think.

There is an edit button, you just need more posts to see it.
 

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