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Anyone install 3+ Powerwalls in San Diego?

Vines

Active Member
Jul 20, 2018
2,288
2,818
Silicon Valley, CA
3 Powerwalls isn't commercial, its called "Large Scale" This will require an NGOM, as pointed out above.
Basically to remove the NGOM, the Powerwall and Gateway must be certified to this new UL Power Control Systems Certification.

I'm sure this is on Tesla list, but as early as March, I'd be surprised. Maybe as long as that's March Elon Time lol. An NGOM isn't expensive or difficult to do, so I don't see why your installer is pushing back. The PGE filing is more involved for "Large scale" systems, but your installer should handle it without problem.
 
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3 Powerwalls isn't commercial, its called "Large Scale" This will require an NGOM, as pointed out above.
Basically to remove the NGOM, the Powerwall and Gateway must be certified to this new UL Power Control Systems Certification.

I'm sure this is on Tesla list, but as early as March, I'd be surprised. Maybe as long as that's March Elon Time lol. An NGOM isn't expensive or difficult to do, so I don't see why your installer is pushing back. The PGE filing is more involved for "Large scale" systems, but your installer should handle it without problem.

Just a guess here, but if one has an NGOM, they're limited to selling solar only energy via NEM. Without NGOM, one can sell solar and battery which can be beneficial for late evening peak times. Once 3+ w/o NGOM is permitted, what do people with NGOM do if they want to sell battery via NEM? Will the NGOM have to be removed?

EDIT: Seems point is moot since currently PW won't allow export to the grid.

The March timeframe was from the utility to support 3+ w/o NGOM requirement, not Tesla.
 
Last edited:
Just a guess here, but if one has an NGOM, they're limited to selling solar only energy via NEM. Without NGOM, one can sell solar and battery which can be beneficial for late evening peak times. Once 3+ w/o NGOM is permitted, what do people with NGOM do if they want to sell battery via NEM? Will the NGOM have to be removed?

EDIT: Seems point is moot since currently PW won't allow export to the grid.

The March timeframe was from the utility to support 3+ w/o NGOM requirement, not Tesla.

Did you install the Powerwalls? If so who did you use for the installation here in SanDiego?
 

bob_p

Active Member
Apr 5, 2012
3,738
2,944
When we were planning our system last fall, our Tesla-approved installer used average projections of solar energy generated per day.

Now that we've had our system running for almost 2 months, it's clear we should have been using the peak solar power generated per day (under clear skies and full sun all day) and not the average (which includes days with little or no sun).

Our installers projected the average solar energy per day would be 37 KWh - the actual peak generated was 49 KWh on sunny days. In February the average solar energy per day was projected as 43 KWh, and the actual peak generation was 59 KWh.

We made the assumption that we wouldn't generate much solar energy during the winter and set our PowerWall reserve to 40%. Last week, we hit 100% on the PowerWalls in early afternoon on consecutive days, and have lowered the reserve %.

Before deciding how many PowerWalls you should have, recommend you use peak projected daily solar energy instead of an average. And if you have access to the information, use historical smart meter data to determine how much energy the house uses during the day - to help estimate how much PowerWall storage you should have.
 

jjrandorin

Moderator, Model 3, Tesla Energy Forums
Moderator
Nov 28, 2018
12,427
14,803
Riverside Co. CA
When we were planning our system last fall, our Tesla-approved installer used average projections of solar energy generated per day.

Now that we've had our system running for almost 2 months, it's clear we should have been using the peak solar power generated per day (under clear skies and full sun all day) and not the average (which includes days with little or no sun).

Our installers projected the average solar energy per day would be 37 KWh - the actual peak generated was 49 KWh on sunny days. In February the average solar energy per day was projected as 43 KWh, and the actual peak generation was 59 KWh.

We made the assumption that we wouldn't generate much solar energy during the winter and set our PowerWall reserve to 40%. Last week, we hit 100% on the PowerWalls in early afternoon on consecutive days, and have lowered the reserve %.

Before deciding how many PowerWalls you should have, recommend you use peak projected daily solar energy instead of an average. And if you have access to the information, use historical smart meter data to determine how much energy the house uses during the day - to help estimate how much PowerWall storage you should have.


It depends on what the goal is for the system, though. For many, they really want to protect against an outage ( so need enough battery to cover from sundown to sun up), and need to cover the peak time of use period that their utility has set.

Thats a different requirement entirely from "I want to capture every kW of solar I am generating and use it myself rather than export it". building for "peak" would mean there would be plenty of times you are not generating peak, so would be somewhat overbuilt for most, but again it all depends on the goal. If self sustainability is the true goal, then one would want to capture all power, not just enough to cover.

I am not on a time of use plan, I am on an old tiered one where I get billed for total usage, so minimizing my use of grid saves me money, not WHEN I use it. I have not changed plans yet because any new plan de values my solar more than I have right now, where I get paid basically 1:1 for solar I export. In my case, the utility was basically a big powerwall for me, so I didnt need powerwalls... up until I had 2 power outages last year and the threat of more utility shut downs in the future for safety reasons.

That changed my thinking, so I got 2 powerwalls, as I did not want to change anything about my current plan. getting 3 powerwalls might have pushed me into another category and changed my interconnect agreement. 2 works fine for me, even though at peak during the summer I generate 50 ish kWh a day and my house only uses about 20-25 kWhs a day without charging my car. With charging my car, I use about 50 kWhs a day.
 
When we were planning our system last fall, our Tesla-approved installer used average projections of solar energy generated per day.

Now that we've had our system running for almost 2 months, it's clear we should have been using the peak solar power generated per day (under clear skies and full sun all day) and not the average (which includes days with little or no sun).

Our installers projected the average solar energy per day would be 37 KWh - the actual peak generated was 49 KWh on sunny days. In February the average solar energy per day was projected as 43 KWh, and the actual peak generation was 59 KWh.

We made the assumption that we wouldn't generate much solar energy during the winter and set our PowerWall reserve to 40%. Last week, we hit 100% on the PowerWalls in early afternoon on consecutive days, and have lowered the reserve %.

Before deciding how many PowerWalls you should have, recommend you use peak projected daily solar energy instead of an average. And if you have access to the information, use historical smart meter data to determine how much energy the house uses during the day - to help estimate how much PowerWall storage you should have.
Thank you.
 
It depends on what the goal is for the system, though. For many, they really want to protect against an outage ( so need enough battery to cover from sundown to sun up), and need to cover the peak time of use period that their utility has set.

Thats a different requirement entirely from "I want to capture every kW of solar I am generating and use it myself rather than export it". building for "peak" would mean there would be plenty of times you are not generating peak, so would be somewhat overbuilt for most, but again it all depends on the goal. If self sustainability is the true goal, then one would want to capture all power, not just enough to cover.

I am not on a time of use plan, I am on an old tiered one where I get billed for total usage, so minimizing my use of grid saves me money, not WHEN I use it. I have not changed plans yet because any new plan de values my solar more than I have right now, where I get paid basically 1:1 for solar I export. In my case, the utility was basically a big powerwall for me, so I didnt need powerwalls... up until I had 2 power outages last year and the threat of more utility shut downs in the future for safety reasons.

That changed my thinking, so I got 2 powerwalls, as I did not want to change anything about my current plan. getting 3 powerwalls might have pushed me into another category and changed my interconnect agreement. 2 works fine for me, even though at peak during the summer I generate 50 ish kWh a day and my house only uses about 20-25 kWhs a day without charging my car. With charging my car, I use about 50 kWhs a day.
Thanks!
 

bob_p

Active Member
Apr 5, 2012
3,738
2,944
We're currently only a normal pay-for-use electricity plan ($.091/KWh) for the first 6 months while our new system is operating.

And when that plan is up for renewal, based on the actual smart meter usage data, we'll decided on switching to a longer term plan, either a normal pay-for-use, "free" nights (and expensive days) or solar buyback plan.

Based on our first month of operation, it appears we are getting so much solar energy during the day, that we may be able to cut our electric costs by around 50% using a "free" nights plan, since we're only using about 20% of our electricity during day hours, even though the electricity rates during the day are 2X the cost of a normal plan.

The solar buyback plan doesn't appear to make much sense if you buy any electricity from the grid, because the electricity rates under the buyback plans in our area is much more expensive than the normal pay-for-use rates.
 

DennyL

Member
Sep 26, 2018
359
187
San Diego, CA
A bump on the thread. Anything changed since? My local installers quotation at 29K before incentives recommends 3 Powerwalls because SGIP are considered commercial, at $.25 a watt. The commercial funds are readily available now per my installers quotation.

Tesla's pricing is 19,500 for 3 Powerwalls plus hardware and labor. I will not need panel upgrades, already have a 200 amp panel when my solar was installed.

Does it make sense to go commercial with the certified 3rd party?
 

Vines

Active Member
Jul 20, 2018
2,288
2,818
Silicon Valley, CA
$29k before incentives is pretty close to to Tesla $19.5k plus hardware and labor (assuming no incentives.) You should get $2-3k per Powerwall in SGIP funds (depends on what step your installer is on). You often get what you pay for, so the Tesla price will have to cut service from somewhere.

Not totally sure how it works in your utility rules, but in PGE territory you would need to install a Subpanel and Net Generation Output Meter to meter the PV only. If you plan on going for SGIP, I'd make sure your installer does that process for you so its painless.

Regardless, the installation queue is filling and the rules as far as allowable locations likely get worse next July. If you want Powerwalls, its not likely to get easier or much cheaper. SGIP funds will run out and the permit requirements will get more strict.
 
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SDM3

Member
Feb 28, 2018
12
1
SD
Any recommended installers in San Diego? Ive spoken to a few of the Tesla certified installers and their quotes for two Powerwalls installed with panel upgrade and gateway range from to $23k before incentives/$13.6k (after sgip and federal tax incentives) to $27k before incentives ($16k after sgip and federal tax incentives).
 

Dave EV

Active Member
Jun 23, 2009
1,955
1,742
San Diego
Any recommended installers in San Diego? Ive spoken to a few of the Tesla certified installers and their quotes for two Powerwalls installed with panel upgrade and gateway range from to $23k before incentives/$13.6k (after sgip and federal tax incentives) to $27k before incentives ($16k after sgip and federal tax incentives).
Seems like pretty typical third party pricing where their price after including SGIP is about the same as Tesla's price without SGIP.

Out of curiosity, what two companies gave you those quotes? Only installer I know off the top of my head is Baker Electric, but I'm sure there's more.
 
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bkp_duke

Well-Known Member
May 15, 2016
5,937
22,956
San Diego, CA
Just a data point for consideration:
- I went with Tesla direct, and the team was VERY helpful on getting things EXACTLY how I wanted, including asthetics.

- My neighbor went with a 3rd party installer, and was not happy (they scratched the powerwalls on install, they were not completely level, etc.).


Do your homework if you go with a 3rd party installer, and hold them to a high standard on your installation.
 

SDM3

Member
Feb 28, 2018
12
1
SD
Seems like pretty typical third party pricing where their price after including SGIP is about the same as Tesla's price without SGIP.

Out of curiosity, what two companies gave you those quotes? Only installer I know off the top of my head is Baker Electric, but I'm sure there's more.
Thanks. Don’t have it in front of me but believe the companies were Stellasolar and hse and one other. I’ll check out baker.
 

Vines

Active Member
Jul 20, 2018
2,288
2,818
Silicon Valley, CA
Just a data point for consideration:
- I went with Tesla direct, and the team was VERY helpful on getting things EXACTLY how I wanted, including asthetics.

- My neighbor went with a 3rd party installer, and was not happy (they scratched the powerwalls on install, they were not completely level, etc.).


Do your homework if you go with a 3rd party installer, and hold them to a high standard on your installation.

Great to hear they took such good care of you. Curious, what was the installation cost Tesla ended up charging, above what the initial quote was for installation?
 

bkp_duke

Well-Known Member
May 15, 2016
5,937
22,956
San Diego, CA
Great to hear they took such good care of you. Curious, what was the installation cost Tesla ended up charging, above what the initial quote was for installation?

They stuck to the quote, we had a contract. At this point, that was 3 years ago this month, so things might have changed a bit.

Still waiting on them to install our 4th powerwall. They tell me everything is on hold due to the coronavirus.
 

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