Welcome to Tesla Motors Club
Discuss Tesla's Model S, Model 3, Model X, Model Y, Cybertruck, Roadster and More.
Register

Existing SunRun 2.8kWh system, want to add more from Tesla and add Powerwalls

This site may earn commission on affiliate links.
Wanted to ask advice from folks here and also @Vines (could not figure out how to PM from here).

Am looking into getting a solar system upgrade possibly with a battery and so wanted to ask for your thoughts and advice.

When we bought our house in San Jose CA, 8 years ago, it already had a 2.8kWh system on it. We assumed the lease from Sunrun and negotiated 22c/kWh with no escalation in price. The house presently has an old 1960's 125A panel on it. And it is totally full with breakers. There is a 60A subpanel supplying our kitchen that was installed in 2015. Also totally full, but potentially can install some slimline breakers to free up a few slots.

Today, we have a Tesla model 3, the house had a pool already, air conditioning, two fridges, etc., and we found our usage at 1300 kWh per month on average last year with COVID and charging the car at home etc vs for free at the office. Adding a 2-ton mini split next week to our big living room/kitchen to fix some HVAC issues. That's another 20A/240V potentially.
Electricity bills right now are about $250/month right now that we pay to PG&E in addition to about $60/month for the existing 2.8kWh solar to Sunrun.

So was considering adding an additional solar/battery system to hopefully save some cost and have a general upgrade to the electrical.

Sunrun is advising me to install a 13000 kWh per year system with a 10kW LG battery backup. Price is $204/month that escalates 2.9%/year.

Do you think this makes sense? Or should I look at Tesla instead? Tesla won't touch the existing system unless I own it. To do that, I'd have to buyout my Sunrun existing 2.8 kWh system and spend $3000 more than what I owe over the remaining 10 years on the PPA. And then $32000 for the Tesla 12.24 kWh with 2 Powerwalls. And also am concerned if the main panel needs to be upgraded from 125A which is a massive cost due to our underground service from the 1960's that would require a new 3" conduit etc. Sunrun says they will cover up to $4000 of this cost if a panel upgrade is needed. Not sure about Tesla.

Thoughts?
 
Wanted to ask advice from folks here and also @Vines (could not figure out how to PM from here).

Am looking into getting a solar system upgrade possibly with a battery and so wanted to ask for your thoughts and advice.

When we bought our house in San Jose CA, 8 years ago, it already had a 2.8kWh system on it. We assumed the lease from Sunrun and negotiated 22c/kWh with no escalation in price. The house presently has an old 1960's 125A panel on it. And it is totally full with breakers. There is a 60A subpanel supplying our kitchen that was installed in 2015. Also totally full, but potentially can install some slimline breakers to free up a few slots.

Today, we have a Tesla model 3, the house had a pool already, air conditioning, two fridges, etc., and we found our usage at 1300 kWh per month on average last year with COVID and charging the car at home etc vs for free at the office. Adding a 2-ton mini split next week to our big living room/kitchen to fix some HVAC issues. That's another 20A/240V potentially.
Electricity bills right now are about $250/month right now that we pay to PG&E in addition to about $60/month for the existing 2.8kWh solar to Sunrun.

So was considering adding an additional solar/battery system to hopefully save some cost and have a general upgrade to the electrical.

Sunrun is advising me to install a 13000 kWh per year system with a 10kW LG battery backup. Price is $204/month that escalates 2.9%/year.

Do you think this makes sense? Or should I look at Tesla instead? Tesla won't touch the existing system unless I own it. To do that, I'd have to buyout my Sunrun existing 2.8 kWh system and spend $3000 more than what I owe over the remaining 10 years on the PPA. And then $32000 for the Tesla 12.24 kWh with 2 Powerwalls. And also am concerned if the main panel needs to be upgraded from 125A which is a massive cost due to our underground service from the 1960's that would require a new 3" conduit etc. Sunrun says they will cover up to $4000 of this cost if a panel upgrade is needed. Not sure about Tesla.

Thoughts?
I have a friend who went with sunrun because cheaper than Tesla
 
Wanted to ask advice from folks here and also @Vines (could not figure out how to PM from here).

Am looking into getting a solar system upgrade possibly with a battery and so wanted to ask for your thoughts and advice.

When we bought our house in San Jose CA, 8 years ago, it already had a 2.8kWh system on it. We assumed the lease from Sunrun and negotiated 22c/kWh with no escalation in price. The house presently has an old 1960's 125A panel on it. And it is totally full with breakers. There is a 60A subpanel supplying our kitchen that was installed in 2015. Also totally full, but potentially can install some slimline breakers to free up a few slots.

Today, we have a Tesla model 3, the house had a pool already, air conditioning, two fridges, etc., and we found our usage at 1300 kWh per month on average last year with COVID and charging the car at home etc vs for free at the office. Adding a 2-ton mini split next week to our big living room/kitchen to fix some HVAC issues. That's another 20A/240V potentially.
Electricity bills right now are about $250/month right now that we pay to PG&E in addition to about $60/month for the existing 2.8kWh solar to Sunrun.

So was considering adding an additional solar/battery system to hopefully save some cost and have a general upgrade to the electrical.

Sunrun is advising me to install a 13000 kWh per year system with a 10kW LG battery backup. Price is $204/month that escalates 2.9%/year.

Do you think this makes sense? Or should I look at Tesla instead? Tesla won't touch the existing system unless I own it. To do that, I'd have to buyout my Sunrun existing 2.8 kWh system and spend $3000 more than what I owe over the remaining 10 years on the PPA. And then $32000 for the Tesla 12.24 kWh with 2 Powerwalls. And also am concerned if the main panel needs to be upgraded from 125A which is a massive cost due to our underground service from the 1960's that would require a new 3" conduit etc. Sunrun says they will cover up to $4000 of this cost if a panel upgrade is needed. Not sure about Tesla.

Thoughts?

Tesla wont even touch the existing system if you DO own it. Pretty much anyone (including tesla) is going to simply put a NEW system on your home (new panels, new inverter, etc).

When you look in detail at "whatever" sunrun is quoting you, you will likely find that, they as well, are not doing anything with the existing system, but simply adding on a new system onto your home.
 
  • Informative
Reactions: pilotSteve
Tesla wont even touch the existing system if you DO own it. Pretty much anyone (including tesla) is going to simply put a NEW system on your home (new panels, new inverter, etc).

When you look in detail at "whatever" sunrun is quoting you, you will likely find that, they as well, are not doing anything with the existing system, but simply adding on a new system onto your home.
Based on the age and size of his system, yep, just taking it out might be the best overall option
 
Wow, I think it's interesting Sunrun is pushing new leads back to that old LG Chem/Brightbox.

Also, Sunrun is charging about $7,200 for the remaining 10 years + $3000 to buy out a 3 kWp system that is about 50% depreciated? Sunrun already front-loads "financing fees" to the borrowed principal if someone pays over time instead of one-time cash. Then they charge early termination fees too? No wonder they kept telling me to finance/lease the system instead of just paying cash up front. Now I want to look at Sunrun's financials to see what % of their revenue comes from financing deals rather than actually installing solar.

I think completely 86'ing the 3 kWp system and starting fresh isn't going to be a smart financial move since you'll have to pay $10k to buy it out. Then another ~$8k to install it anew as part of your new system.

I agree that @Vines can help you design a solution that will make sense. A couple of questions will help make it easier to understand the pain you might encounter trying to move up from 125A to 200A.

1) Are you served by PG&E via above-ground lines or from underground?
2) Is your main service panel (with meter socket) at 36 inches or more away from your gas riser? (measured square; not a radius)
 
  • Like
Reactions: charlesj
Wow. Are you leasing that small system forever or there is an expiration time on it. Expensive rent.
From your usage average, 1,300 kWh per month, your annual usage is 15,600 kWh. If you are expanding, try to get rid of what you have and upgrade at least to
that 15.6 mWh and if you can, add 10%. Try not to lease it, then compare prices and with at least 2 if not 3 Tesla Batteries.
That 10 kW battery suggested is peanuts. ;) ;)

ps. that main panel needs to be replace at least with a true 200A panel. At least that is what I am seeing here with feedback from members.
 
Tesla wont even touch the existing system if you DO own it. Pretty much anyone (including tesla) is going to simply put a NEW system on your home (new panels, new inverter, etc).

When you look in detail at "whatever" sunrun is quoting you, you will likely find that, they as well, are not doing anything with the existing system, but simply adding on a new system onto your home.
Yes, you're right. I don't think they will do anything to the old system.
 
Wow. Are you leasing that small system forever or there is an expiration time on it. Expensive rent.
From your usage average, 1,300 kWh per month, your annual usage is 15,600 kWh. If you are expanding, try to get rid of what you have and upgrade at least to
that 15.6 mWh and if you can, add 10%. Try not to lease it, then compare prices and with at least 2 if not 3 Tesla Batteries.
That 10 kW battery suggested is peanuts. ;) ;)

ps. that main panel needs to be replace at least with a true 200A panel. At least that is what I am seeing here with feedback from members.
Expiration is in 10 years (previous homeowners had a 20 year PPA lease). The usage is high - perhaps I have something else going on. Getting rid of what we have will be expensive because of what another poster posted.
 
If you must keep old system, you have room for a large new system, hopefully the balance of that old annual production and the total of about 17 megWh annual need, get bids for cash payment for the remainder from both companies. Call that $60/mo a learning tuition. :)
 
Wow, I think it's interesting Sunrun is pushing new leads back to that old LG Chem/Brightbox.

Also, Sunrun is charging about $7,200 for the remaining 10 years + $3000 to buy out a 3 kWp system that is about 50% depreciated? Sunrun already front-loads "financing fees" to the borrowed principal if someone pays over time instead of one-time cash. Then they charge early termination fees too? No wonder they kept telling me to finance/lease the system instead of just paying cash up front. Now I want to look at Sunrun's financials to see what % of their revenue comes from financing deals rather than actually installing solar.

I think completely 86'ing the 3 kWp system and starting fresh isn't going to be a smart financial move since you'll have to pay $10k to buy it out. Then another ~$8k to install it anew as part of your new system.

I agree that @Vines can help you design a solution that will make sense. A couple of questions will help make it easier to understand the pain you might encounter trying to move up from 125A to 200A.

1) Are you served by PG&E via above-ground lines or from underground?
2) Is your main service panel (with meter socket) at 36 inches or more away from your gas riser? (measured square; not a radius)
Hi holeydonut. Correct. Sunrun will charge me a bit less than $10000 to 'buyout' my system, in case Tesla would need me to do that in order to add theirs on - let's see. Sunrun definitely makes it more attractive to go with a monthly payment than a buyout (for their options). Tesla is a heck of a lot cheaper but you have to pay up front and get back the $11K or whatever in Federal Tax credits.
Agree 86'ing the existing doesn't make sense given where we are with this present PPA. But the way I look at it is this.
I'd pay $7200 to SunRun over 10 years. In today's $'s at 3% interest rate (e.g. I pull from a HELOC), it's about $6150. So this means SunRun is charging me $4000 to 'buyout' the system, which I need to check what that does to the warranty...

Ok so $4000 is where I start.
Then Tesla $33000 (After Federal Tax Credit). BIG QUESTION: Will Tesla agree to intstall a second new system in addition to the SunRun even if I own it outright? Not sure.

SO $36000 I am done, assuming I do not need to mess with the panel, which I might very well need to, and then the question is does Tesla help me with this or not? Let's say I keep this house another 10 years, I'm probably ahead vs. staying with PG&E.

Re moving up to a 200A panel: underground, and PG&E wants us to trench about 50' and put in a new 3" conduit and sweep/chase leading to the new panel area. Gas meter isn't an issue, but an existing fence is :(. So I am going to consult an electrician next week to see whether my existing 125A box area could be used as a sub panel. Then I could have a:
1. New 200A main panel (plenty of space 6-7 feet to the right of the existing panel).
2. Replace the existing panel with a sub-panel or junction box.
3. Run any new circuits to the new main panel if I ever need anything in the future.

Not sure if this will work, will try to find out next week.
 
Hi holeydonut. Correct. Sunrun will charge me a bit less than $10000 to 'buyout' my system, in case Tesla would need me to do that in order to add theirs on - let's see. Sunrun definitely makes it more attractive to go with a monthly payment than a buyout (for their options). Tesla is a heck of a lot cheaper but you have to pay up front and get back the $11K or whatever in Federal Tax credits.
Agree 86'ing the existing doesn't make sense given where we are with this present PPA. But the way I look at it is this.
I'd pay $7200 to SunRun over 10 years. In today's $'s at 3% interest rate (e.g. I pull from a HELOC), it's about $6150. So this means SunRun is charging me $4000 to 'buyout' the system, which I need to check what that does to the warranty...

Ok so $4000 is where I start.
Then Tesla $33000 (After Federal Tax Credit). BIG QUESTION: Will Tesla agree to intstall a second new system in addition to the SunRun even if I own it outright? Not sure.

SO $36000 I am done, assuming I do not need to mess with the panel, which I might very well need to, and then the question is does Tesla help me with this or not? Let's say I keep this house another 10 years, I'm probably ahead vs. staying with PG&E.

Re moving up to a 200A panel: underground, and PG&E wants us to trench about 50' and put in a new 3" conduit and sweep/chase leading to the new panel area. Gas meter isn't an issue, but an existing fence is :(. So I am going to consult an electrician next week to see whether my existing 125A box area could be used as a sub panel. Then I could have a:
1. New 200A main panel (plenty of space 6-7 feet to the right of the existing panel).
2. Replace the existing panel with a sub-panel or junction box.
3. Run any new circuits to the new main panel if I ever need anything in the future.

Not sure if this will work, will try to find out next week.


Wow yeah, at first blush I think getting you the proper-sized solar (and a possible ESS) is going to be a rather tough project for your house. Definitely not the type of thing the corporates (Tesla, Sunrun, Sunpower, etc) will do since there's too much liability and complexity involved. These companies operate on volume business with low margins. They don't like expending energy on special snowflakes.

One last question... is your solar directly spliced into the load side of your main panel? Or is your solar backfeeding through something that is tied into a breaker spot on your main panel? Some of the older, smaller installs didn't use a generation panel or breaker protecting the solar current. They basically just spliced into the load side between the meter socket and main panel. (Of course, a blade disconnect would be there for rapid shutdown... because blade disconnects are awesome).

Yeah, if you could some how get PG&E to basically work with you to upgrade to a brand spanking new 200A main service panel and meter socket... then I could envision you using your current MSP area as a sort of sub-panel. But, your costs to get all this plus put in all the battery stuff may start to give you sticker shock.

Good luck!
 
As folks have pointed out, any new panels or batteries are going to be independent of the old system.

But I don't see why people are complaining about the old system, except that it is taking up probably some good roof real estate for a new system. 22c/kwh is 22c/kwh, regardless of how old/new, efficient/inefficient the system is. It's better than EV2-A daytime rates. Better than E-1 Tier 2 rates, which the OP would be paying, as well as Tier 1. Better than E-TOU-C Tier 2 rates, as well as Tier 1. By the end of those 10 years, Tier 1 rates on any plan are likely going to be >40c/kwh. If the $60/month is paying for production at 22c/kwh, that's a fair deal, and seems like the production is decent for a 10-year old system.

It just doesn't make financial sense to pay Sunrun something close to the original price of the 2.8kwh system to rip it out, and then pay again to put back in different panels, just because the current system is 10 years old.
 
Last edited:
Hi holeydonut. Correct. Sunrun will charge me a bit less than $10000 to 'buyout' my system, in case Tesla would need me to do that in order to add theirs on - let's see. Sunrun definitely makes it more attractive to go with a monthly payment than a buyout (for their options). Tesla is a heck of a lot cheaper but you have to pay up front and get back the $11K or whatever in Federal Tax credits.
Agree 86'ing the existing doesn't make sense given where we are with this present PPA. But the way I look at it is this.
I'd pay $7200 to SunRun over 10 years. In today's $'s at 3% interest rate (e.g. I pull from a HELOC), it's about $6150. So this means SunRun is charging me $4000 to 'buyout' the system, which I need to check what that does to the warranty...

Ok so $4000 is where I start.
Then Tesla $33000 (After Federal Tax Credit). BIG QUESTION: Will Tesla agree to intstall a second new system in addition to the SunRun even if I own it outright? Not sure.

SO $36000 I am done, assuming I do not need to mess with the panel, which I might very well need to, and then the question is does Tesla help me with this or not? Let's say I keep this house another 10 years, I'm probably ahead vs. staying with PG&E.

Re moving up to a 200A panel: underground, and PG&E wants us to trench about 50' and put in a new 3" conduit and sweep/chase leading to the new panel area. Gas meter isn't an issue, but an existing fence is :(. So I am going to consult an electrician next week to see whether my existing 125A box area could be used as a sub panel. Then I could have a:
1. New 200A main panel (plenty of space 6-7 feet to the right of the existing panel).
2. Replace the existing panel with a sub-panel or junction box.
3. Run any new circuits to the new main panel if I ever need anything in the future.

Not sure if this will work, will try to find out next week.
First, if your existing panels use your best solar exposure, ....

But, for all the cost, unless you have planning to stay in the home over 20 years, IMO, you might be better to do nothing and just pay the monthly bills
 
As folks have pointed out, any new panels or batteries are going to be independent of the old system.

But I don't see why people are complaining about the old system, except that it is taking up probably some good roof real estate for a new system. 22c/kwh is 22c/kwh, regardless of how old/new, efficient/inefficient the system is. It's better than EV2-A daytime rates. Better than E-1 Tier 2 rates, which the OP would be paying, as well as Tier 1. Better than E-TOU-C Tier 2 rates, as well as Tier 1. By the end of those 10 years, Tier 1 rates on any plan are likely going to be >40c/kwh. If the $60/month is paying for production at 22c/kwh, that's a fair deal, and seems like the production is decent for a 10-year old system.

It just doesn't make financial sense to pay Sunrun something close to the original price of the 2.8kwh system to rip it out, and then pay again to put back in different panels, just because the current system is 10 years old.
Agree. Keeping the existing is the way to go.
 
Wow yeah, at first blush I think getting you the proper-sized solar (and a possible ESS) is going to be a rather tough project for your house. Definitely not the type of thing the corporates (Tesla, Sunrun, Sunpower, etc) will do since there's too much liability and complexity involved. These companies operate on volume business with low margins. They don't like expending energy on special snowflakes.

One last question... is your solar directly spliced into the load side of your main panel? Or is your solar backfeeding through something that is tied into a breaker spot on your main panel? Some of the older, smaller installs didn't use a generation panel or breaker protecting the solar current. They basically just spliced into the load side between the meter socket and main panel. (Of course, a blade disconnect would be there for rapid shutdown... because blade disconnects are awesome).

Yeah, if you could some how get PG&E to basically work with you to upgrade to a brand spanking new 200A main service panel and meter socket... then I could envision you using your current MSP area as a sort of sub-panel. But, your costs to get all this plus put in all the battery stuff may start to give you sticker shock.

Good luck!
PG&E was estimating $7000 + cost of new panel (ouch) = $10000 just to get to a 200A MSP starting point. This whole thing feels completely crazy.
 
First, if your existing panels use your best solar exposure, ....

But, for all the cost, unless you have planning to stay in the home over 20 years, IMO, you might be better to do nothing and just pay the monthly bills
Given the way PG&E is escalating and also given increasing loads, I think that this project probably does have value. Will look at what I find out in the next week or so and update here.
 
Are you saying that Tesla won't even install another system independent of the existing SunRun systems unless you owned it?

Your SunRun price quoted a "10 kW" battery? Was that a typo and that is a 10kWh battery? If so that's significantly different from your Tesla quote with two Powerwalls which is over 26 kWh.

The ideal situation in my mind (which others have suggested) is to find a way to just keep paying SunRun for the remainder for the that agreement and add additional solar. Tesla's current pricing (and anyone else offering similar) should price out less than $0.15/ kWh even on less than optimal roof positions. You can potentially get below $0.10 kWh.

You should so the battery economic analysis separately. It is a tough road if you want them for just economic reasons; very roughly they double your cost per kWh. A possible benefit from the Powerwalls/Tesla Gateway 2 is the ability to install a 200A load center while keeping your PG&E at 125A.
 
Are you saying that Tesla won't even install another system independent of the existing SunRun systems unless you owned it?

Your SunRun price quoted a "10 kW" battery? Was that a typo and that is a 10kWh battery? If so that's significantly different from your Tesla quote with two Powerwalls which is over 26 kWh.

The ideal situation in my mind (which others have suggested) is to find a way to just keep paying SunRun for the remainder for the that agreement and add additional solar. Tesla's current pricing (and anyone else offering similar) should price out less than $0.15/ kWh even on less than optimal roof positions. You can potentially get below $0.10 kWh.

You should so the battery economic analysis separately. It is a tough road if you want them for just economic reasons; very roughly they double your cost per kWh. A possible benefit from the Powerwalls/Tesla Gateway 2 is the ability to install a 200A load center while keeping your PG&E at 125A.
Oh this is interesting. You're saying I can use the batteries and additional Tesla solar to draw more.amps than the 125A PG&E without updating my main service panel? If so, that would be exactly what I'm looking for. As for adding to the SunRun, TBD whether Tesla or anyone would agree to add to it. Trying to find out.