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Panel upgrade

Eric99

Member
Aug 14, 2020
55
30
East Bay Area CA
2555C71A-EF51-4282-AFB0-8605BE6C1C98.jpeg
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I “think” the first step i should do in preparation for solar is to upgrade my main panel. Its from the 60s. 100 amp. Can you guys take a look and steer me in the right direction? Ive never seen a main panel with just a main disconnect and no additional breakers. Id like to upgrade it to 200 amps and have some slots for additional breakers.
Sorry pictures are sideways for some reason
 

BrettS

Active Member
Mar 28, 2017
2,131
2,547
Orlando, FL
If you are planning to install powerwalls with a whole home backup then that main breaker is all you really need. That breaker would feed your TEG (Tesla Energy Gateway) and all the rest of your circuits would be behind the gateway. Even if you had more room for additional breakers in that panel you wouldn’t put any there.

If you are just getting solar only or powerwalls with a partial home backup solution, then you could potentially put non backed up circuits in the main panel.

Either way the panel will need to be replaced if you want to upgrade to 200A service.
 
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BrettS

Active Member
Mar 28, 2017
2,131
2,547
Orlando, FL
Also, you shouldn’t need to do anything with that panel before you order solar. Your solar installer will be able to work with you to upgrade that panel, if necessary, as part of the solar install. That way you won’t have to worry about putting something in that may not work well with your new solar system,
 

Eric99

Member
Aug 14, 2020
55
30
East Bay Area CA
Thanks for the info Brett! That makes a lot of sense. I was trying to get things done upfront and also cheaper. As im typing this my co-worker came by and told me he’s in the process of installing tesla Solar and when they showed up for the install, the installer said his panel needs upgrading. $4200 quote.. thats what id like to avoid.
 

miimura

Well-Known Member
Aug 21, 2013
6,498
6,260
Los Altos, CA
Thanks for the info Brett! That makes a lot of sense. I was trying to get things done upfront and also cheaper. As im typing this my co-worker came by and told me he’s in the process of installing tesla Solar and when they showed up for the install, the installer said his panel needs upgrading. $4200 quote.. thats what id like to avoid.
Keep in mind that if the solar installer does it, you can take the federal tax credit on it. Also, no guarantee that another electrician would charge you less for the same work as a separate job.
 

BrettS

Active Member
Mar 28, 2017
2,131
2,547
Orlando, FL
Thanks for the info Brett! That makes a lot of sense. I was trying to get things done upfront and also cheaper. As im typing this my co-worker came by and told me he’s in the process of installing tesla Solar and when they showed up for the install, the installer said his panel needs upgrading. $4200 quote.. thats what id like to avoid.

It’s very unusual that they wouldn’t notice that the panel needs upgraded before install day. When you place a tesla solar order they ask you to do a home assessment that includes sending pictures of your panels and the labels on those panels to tesla. That way they know exactly what you have and they can determine if a panel replacement is needed ahead of time.

$4200 definitely sounds in the right ballpark for a panel replacement, but it will probably be more if you want to upgrade your service at the same time. From the quotes I’ve seen people post on here it seems like tesla is reasonably competitive on that sort of work.

Of course if you are going to have to pay an extra $4200 you certainly would want to know before they are there to do the install.
 

SoCal Dave

Member
Jul 30, 2020
420
317
California
Keep in mind that if the solar installer does it, you can take the federal tax credit on it. Also, no guarantee that another electrician would charge you less for the same work as a separate job.

My understanding of the solar credit is it isn't required to be done by the solar company. As long as one can clearly show the work was done as a requirement for the solar installation they should be fine. A roof replacement is the one exception for this.

Standard note: you probably want to consult a tax person and not depend on some weirdo on the internet
 

P85_DA

Supporting Member
Supporting Member
Apr 25, 2015
4,221
2,953
CA
Where are your breakers ?? That $4200 price is in ballpark if u need to put new panel in
 

SaveOurPlanet

Member
Jan 6, 2018
252
150
San Francisco
Just curious, does anyone know if Tesla upgrades your panel to 200 amps would that require a PG&E service upgrade as well? I tried to get service upgrade before when I got my Model S but was told by electrician that because my incoming wire is underground, it would take at least 3 to 6 months and over 12,000.00 for PG&E to do that, PG&E charges by the foot.
 

miimura

Well-Known Member
Aug 21, 2013
6,498
6,260
Los Altos, CA
Just curious, does anyone know if Tesla upgrades your panel to 200 amps would that require a PG&E service upgrade as well? I tried to get service upgrade before when I got my Model S but was told by electrician that because my incoming wire is underground, it would take at least 3 to 6 months and over 12,000.00 for PG&E to do that, PG&E charges by the foot.
If your service is rated 100A, then the main breaker must be 100A. However, you can put a 100A main breaker in a 200A panel, if necessary.

In PG&E territory, if you want to upgrade your service, you are responsible for the cost of the wire to the nearest pole or other junction point. PG&E is responsible for the transformer.
 

BrettS

Active Member
Mar 28, 2017
2,131
2,547
Orlando, FL
Just curious, does anyone know if Tesla upgrades your panel to 200 amps would that require a PG&E service upgrade as well? I tried to get service upgrade before when I got my Model S but was told by electrician that because my incoming wire is underground, it would take at least 3 to 6 months and over 12,000.00 for PG&E to do that, PG&E charges by the foot.

I’m not quite sure what your goal is. You could put on a 200A panel with 100A service, but I’m not sure that there’s much of a point to that. Your main breaker would still have to be 100A. If you want 200A service you would need more than a panel upgrade and it would be expensive.
 

SaveOurPlanet

Member
Jan 6, 2018
252
150
San Francisco
I have 125 amps service that satisfies my household loads and have no real desire to upgrade, but confused when people say Tesla wants to upgrade their panel. I mean why would Tesla want larger capacity than the service?
 

SoCal Dave

Member
Jul 30, 2020
420
317
California
I have 125 amps service that satisfies my household loads and have no real desire to upgrade, but confused when people say Tesla wants to upgrade their panel. I mean why would Tesla want larger capacity than the service?

Typically it is to meet the NEC 120% requirement for a solar breaker and main breaker combination.

If you have a 100A service with a 100A main breaker, you only can have a 20A solar breaker. If you upgrade the service to a 200A then you can have a 40A solar breaker. Or you can go with a 200A service, 175A main and then still have 65A for solar.
 

SaveOurPlanet

Member
Jan 6, 2018
252
150
San Francisco
Thanks much for the explanation, so for my case I have 125 amps service panel so my 120% NEC requirement would be 150 amps? So my solar breaker would be 25 amps? What's the implication, my solar generation cannot exceed 25 amps?
 

wwhitney

Member
Nov 2, 2017
968
1,320
Berkeley, CA
Typically it is to meet the NEC 120% requirement for a solar breaker and main breaker combination.
For a combined meter/main/distribution panel. For just a meter/main, or any residential service with a separate meter enclosure, there are usually alternative solutions.

So for the OP, it should be possible to install up to 80A of generation without changing that service panel, e.g. (2) Powerwalls and a 7.68 kW solar inverter. Of course, as the service panel is over 50 years old, it may be due for replacement anyway.

Cheers, Wayne
 

jeremymc7

Active Member
Feb 3, 2013
1,563
713
U.S.
If I recall SCE told me that if I wanted to go from 100A to 200A they would do the pole line to the roof, not panel, for no charge. If I wanted more than 200A they would have to charge.
 

SoCal Dave

Member
Jul 30, 2020
420
317
California
Thanks much for the explanation, so for my case I have 125 amps service panel so my 120% NEC requirement would be 150 amps? So my solar breaker would be 25 amps? What's the implication, my solar generation cannot exceed 25 amps?

Yes, doing nothing you would be limited to 25A if your solar fed into your main panel. The cheapest thing would be to derate your main breaker to a 100A which would give you 50A available for solar. Tesla did that with my 200A panel. Switched out the main for a 175A to give me capacity for a large enough solar breaker.
 

sleevemedia

Member
Jul 1, 2020
57
41
Orlando
I should share my experience.

Before install, I had a typical central Florida outdoor split meter/main and a separate service panel in the garage. The service panel in the garage is full, as a result a 2014 patio upgrade by the former owners added loads in the outdoor panel. The outdoor split is 150A rated.

During install, an additional 200A panel was installed next to the outdoor split. This panel contained a new 150A main, the loads from the split, the Powerblaster device, and the line tap from the inverters. (Inverters > 100A subpanel with a 60A and 40A backfed > AC disconnect > new panel > line tap > utility service cables.) The panel was rated 200A, giving me a 250A busbar maximum for a 150A main and 100A from the inverters (19kW system). The garage panel remained untouched.

So in terms of a panel upgrade, no, they didn't remove and rewire my garage panel. But they did bring the outdoor main and the loads from the split into a new panel with a new main and new breakers then connect all the new breakers with the existing load cables using a few feet of wire and wire nuts for each load circuit and low gauge cable and taps for the service cable.

No additional charge.
 

Vines

Active Member
Jul 20, 2018
2,052
2,380
Silicon Valley, CA
OP, unless you are popping that main breaker I'd leave it alone.

Your new PV and PW system will give you some room for additional breakers. Also the new generation sources will add to your homes service capacity, at least while the batteries are charged or the sun is shining.

If you do replace it with a 200A service, know that the underground portion will be on you and 10-30k typically. Service upgrades on SHARED transformers are on PGE. If the transformer only serves you then its on you.

I would replace it with the same style, main breaker only. If you must get a combo panel, get one that can take a 200A breaker on the distribution bus such as the square D SC3040M200 F (Series M02) This will give you full flexibility later to do anything that is code complaint.
 
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