Tesla Solar Quote Downgraded to Small System - Worth It Still?

[ftrv8]

Moderator note: By OP request, removed an attachment with personal information.

All,

I've been researching lots, and settled at Tesla's medium sized package with two PWs. But they came back and said they can only do a 3.78 kWh system due to roof shape. I asked them if they can add few more panels, and the second revision still came back to the same system because of setbacks etc. Tesla wouldn't budget. 12 panels and 2 PWs.

Another installer said they could do 21 panels, but that seems kinda fishy (see attached pic of my roof). Not sure how second installer can breach all the setbacks and codes. Unless its a bait and switch thing.

Would you guys/gals think this would be viable for my house? Tesla's 3.78 kWh system with two Powerwalls? Would the PWs even get used to the max capacity and usage?

Stats:

Home: 2400 sq ft home, two stories
Average kWh use monthly: 760 kWh
My provider in Central Valley Cali is Modesto Irrigation District, three tier kWh pricing.

 

[jjrandorin]

im no expert on this, but when I was going through this with solar city in 2015, I had to force them to quote me using roof planes other than the "most optimal" one. My guess is, tesla is only quoting you the "most optimal" roof planes, and the third party installer is quoting you more coverage vs that one side tesla is quoting.

As for whether its worth it, I personally would want a bigger system. In my opinion the goal of having solar should be to offset as close to 100% of your expected usage as you can, and that includes any EV purchases in the near future, etc. When people get solar, they tend to use more energy... even if their solar is not offsetting their entire energy usage. Then, you have a situation where you are paying into tier 2 or even tier 3 rates, while also having solar. That would drive me crazy.

I also understand that it can end up not cost effective to "oversize" too much, because the rates for buyback are not that great (and utilties will generally only let you size to 100% of your expected usage).

What size is the third party installers quote (not panel size, estimated production)?

 

[jboy210]

I would get a layout from the second company and then compare. The design from Tesla has no panels on the SouthEast facing roof which should be higher producing than the NorthWest facing design Tesla has done.But I can surely see why Tesla did the design that way. The roof is small and has lot going on on that SouthEast side.

Just curious, what is driving your decision? We used to own a rental condo in MH and I remember the electricity being pretty cheap. Certainly a lot cheaper than to the West into PG&E territory. Is it the 3 tier structure?

 

[sparkz]

I would get a layout from the second company and then compare. The design from Tesla has no panels on the SouthEast facing roof which should be higher producing than the NorthWest facing design Tesla has done.But I can surely see why Tesla did the design that way. The roof is small and has lot going on on that SouthEast side.

I agree. Get another quote/layout from somewhere else. Its odd they didn’t utilise the south-east facing roof. Also, other installers can probably put a few different sized panels (like the taller higher wattage ones) in to get more out of it. I installed my own Enphase system which works well for this as each panel has a micro-inverter, but Tesla don’t do Enphase as far as I know.
Also, I don’t think you’d get the full benefit of the 2nd powerwall with a little system like that, unless you just want to buy cheaper power, but if you aren’t getting it from the sun, the ROI is long.

 

[jboy210]

I agree. Get another quote/layout from somewhere else. Its odd they didn’t utilise the south-east facing roof. Also, other installers can probably put a few different sized panels (like the taller higher wattage ones) in to get more out of it. I installed my own Enphase system which works well for this as each panel has a micro-inverter, but Tesla don’t do Enphase as far as I know.
Also, I don’t think you’d get the full benefit of the 2nd powerwall with a little system like that, unless you just want to buy cheaper power, but if you aren’t getting it from the sun, the ROI is long.

I am curious if they are going into that 3rd tier pricing which can be very expensive. For some utilities that is 3 times the first tier. So A/C can put you in their pretty easily, especially in MH where temps close to 110 can occur.

 

[ftrv8]

im no expert on this, but when I was going through this with solar city in 2015, I had to force them to quote me using roof planes other than the "most optimal" one. My guess is, tesla is only quoting you the "most optimal" roof planes, and the third party installer is quoting you more coverage vs that one side tesla is quoting.

As for whether its worth it, I personally would want a bigger system. In my opinion the goal of having solar should be to offset as close to 100% of your expected usage as you can, and that includes any EV purchases in the near future, etc. When people get solar, they tend to use more energy... even if their solar is not offsetting their entire energy usage. Then, you have a situation where you are paying into tier 2 or even tier 3 rates, while also having solar. That would drive me crazy.

I also understand that it can end up not cost effective to "oversize" too much, because the rates for buyback are not that great (and utilties will generally only let you size to 100% of your expected usage).

What size is the third party installers quote (not panel size, estimated production)?

My thoughts exactly! If I am going to put something up there, I’d rather put max capacity system. I don’t care it is Tetris style and all over the place. Thanks for taking the time to replay!

 

[ftrv8]

I agree. Get another quote/layout from somewhere else. Its odd they didn’t utilise the south-east facing roof. Also, other installers can probably put a few different sized panels (like the taller higher wattage ones) in to get more out of it. I installed my own Enphase system which works well for this as each panel has a micro-inverter, but Tesla don’t do Enphase as far as I know.
Also, I don’t think you’d get the full benefit of the 2nd powerwall with a little system like that, unless you just want to buy cheaper power, but if you aren’t getting it from the sun, the ROI is long.

Agreed. Going to get other quotes. 2nd installer was Sempris Solaris. Going to see what SunPower says.

 

[ftrv8]

Yup. Third tier in summer pushes us to $400. $250 otherwise.

 

[ftrv8]

I am curious if they are going into that 3rd tier pricing which can be very expensive. For some utilities that is 3 times the first tier. So A/C can put you in their pretty easily, especially in MH where temps close to 110 can occur.

Third tier is getting crazy.

 

[getakey]

what is the $/kWh in third tier?

For PG&E, they require you to go on time of use pricing when you install solar

 

[jjrandorin]

what is the $/kWh in third tier?

For PG&E, they require you to go on time of use pricing when you install solar

Im still on a tiered plan in So cal Edison territory, and since my solar was installed in 2015 I didnt have to change it. I am on NEM 1.0 and getting the solar took me from being in tier 4 all the time (when there were 4 tiers) to being only in tier 1.

In any case, my tiers are 20, 26, 46. I am never in any tier higher than tier 1, and normally am very close to net neutral on true up (paid $125 at true up last year, after getting the model 3 and charging at home for an entire year.)

 

[Boatguy]

I had a similar problem with my house. Same size, three stories and some skylights. My home has used about 700kWh / month this year, excluding car charging (separate panel and meter). I live in Sausalito which gets a lot of fog and morning overcast. I ended up with a small Tesla system and two Powerwalls. I was not expecting much from the solar, and was buying mostly for the Powerwalls to protect from PG&E shutdowns. Adding the solar panels qualified the whole system for the tax credits.

I've been pleasantly surprised. Year to date my house has consumed 3,342kWh of which 2,068 has come from solar and I've sent 450kWh to the grid. That five months is obviously winter and some spring. In the month of May my home has been 86% solar powered. The numbers shift around depending on how much of the PWs is kept in reserve for power outages and how much is used to buffer the solar and shift the daytime power into night. That may be less of an issue for you if you are running air conditioning during the day.

I was also pleasantly surprised by the installation process. The customer communication is horrendous. They were always saying one thing and doing another, but fortunately the error has been to show up when they said they couldn't! This happened during the install and then most recently there was a little rattle from something loose. I sent an email last Friday, they responded on Monday and asked for pictures. I told them I couldn't take pictures (roof is too difficult to access). I got an email Tuesday morning at 9am that they were coming Tuesday morning between 7-9am, which obviously they did not. Then I got an email saying they were coming next week. Then I got a phone call that they were on their way! They arrived 25min later and spent 20min on the roof fixing the problem. I emailed Friday afternoon and it was fixed on Tuesday morning. Communication horrible and inaccurate, but service was excellent.

Good luck!

 

[SoundDaTrumpet]

@ftrv8

I've been researching lots, and settled at Tesla's medium sized package with two PWs. But they came back and said they can only do a 3.78 kWh system due to roof shape. I asked them if they can add few more panels, and the second revision still came back to the same system because of setbacks etc. Tesla wouldn't budget. 12 panels and 2 PWs.

The setback appears compliant to current rules. Front of house access to ridge to cut open vents prior to fire fighting inside the home. Formerly this applied to every roof section.

Tesla prefers string inverters, period. Lowest cost and simplicity. This means two similar sized arrays on the same roof or on two roof orientations for inverters less than 5kW. 3 orientations for >5kW. If you need 4 separate arrays then you'd need two 3.8kW inverters.

Another installer said they could do 21 panels, but that seems kinda fishy (see attached pic of my roof). Not sure how second installer can breach all the setbacks and codes. Unless its a bait and switch thing.

This is not fishy. They are planning to use 100% different approach than Tesla. Semper must be using costly microinverters. It will not be cheap. You can specify a higher density panel like a 360W.

Sunpower panels are slightly smaller dimensions, and are higher density. Unfortunately SunWorks which I recommend you get a quote do not use SunPower panels anymore.

Would you guys/gals think this would be viable for my house? Tesla's 3.78 kWh system with two Powerwalls? Would the PWs even get used to the max capacity and usage?

3.78kW [sic] is not small. I have a 4.2kW and it filled up 90X over the past 12 months. (CA SGIP requires 52 discharges per yr). You can configure to using Time Base Control: Cost Savings and it will use PW during peak and send 100% to grid. This is will boost PW usage considerably.

 

[getakey]

Im still on a tiered plan in So cal Edison territory, and since my solar was installed in 2015 I didnt have to change it. I am on NEM 1.0 and getting the solar took me from being in tier 4 all the time (when there were 4 tiers) to being only in tier 1.

In any case, my tiers are 20, 26, 46. I am never in any tier higher than tier 1, and normally am very close to net neutral on true up (paid $125 at true up last year, after getting the model 3 and charging at home for an entire year.)

I'm on PG&E EV plan. Have Off Peak, Partial Peak, and Peak. During summer those are .12, .28, .53. Off peak is 11pm to 7am. Peak is 2pm to 9pm. I have 11kW (non Tesla) Solar. Added 3 Powerwalls beginning of this year. Thought I was totally gone from Peak rate, but the last 3 days have been 100 degrees. The PWs can only power the house until about 6:30. (I keep 30% reerve) I'll get some solar production intil 7:30 ish, but have to buy from the grid at Peak until 9pm.

 

[SoundDaTrumpet]

I'm on PG&E EV plan. Have Off Peak, Partial Peak, and Peak. During summer those are .12, .28, .53. Off peak is 11pm to 7am. Peak is 2pm to 9pm. I have 11kW (non Tesla) Solar. Added 3 Powerwalls beginning of this year. Thought I was totally gone from Peak rate, but the last 3 days have been 100 degrees. The PWs can only power the house until about 6:30. (I keep 30% reerve) I'll get some solar production intil 7:30 ish, but have to buy from the grid at Peak until 9pm.

@getakey I am loving the heat wave as it provides some worst case data. The Tesla app is pretty cool... as it tracks consumption. I have discovered and calculated that I can get a equivalent to a free PW if I simply replace my 10 SEER A/C to the current 14 SEER standard! I use cost-savings mode with peak at 2-9pm and off peak on everything else. Such settings pushes solar to the grid during grid... which is great for rate arbitrage ($), but leave me empty into the night. Also, set to 15% reserve because it's likely it'll be sunny tomorrow.

 

[charlesj]

Welcome.
Boy, yes, your roof is chopped up on the better sides.

That is a lot of power usage; must be all electric home?

My system is almost South, a little larger that your Tesla quote, older with 17 panels of 235W. Generates about 6mWh per year over the years.
Yes, get those quotes from the other installers and have them or make them understand to install and wire it so you can easily install backup batteries in the "future." Don't tell them about Tesla batteries as they may want to do some others.

Here iare pictures of my recent battery install, post 23
Powerwall 2 Design

Tesla can do batteries after you have solar as I did, way after.

 

[getakey]

@getakey I am loving the heat wave as it provides some worst case data. The Tesla app is pretty cool... as it tracks consumption. I have discovered and calculated that I can get a equivalent to a free PW if I simply replace my 10 SEER A/C to the current 14 SEER standard! I use cost-savings mode with peak at 2-9pm and off peak on everything else. Such settings pushes solar to the grid during grid... which is great for rate arbitrage ($), but leave me empty into the night. Also, set to 15% reserve because it's likely it'll be sunny tomorrow.

In the App, I do the same thing - I put Off peak from 7am to 2pm. When I put that as Partial Peak, it behaved strangely not always charging the PW to 100%

 

[GenSao]

Welcome to the TMC. Enjoy your stay.

Get 3-5 different quotes. Consider installing a system that meets 90-100% of your annual usage.

Tesla may have a great price, but their prescriptive (cookie cutter) approach may not work in your case. Due to the limited roof space, you may find it better to have a third party install solar first to maximize your solar system. Then have Tesla come in to later to install Powerwalls. Typically this approach is more cost effective than having a third party do it all.

Also, be mindful on sharing personal information online. If possible, redact some information on the image you attached.

 

[ftrv8]

Welcome to the TMC. Enjoy your stay.

Get 3-5 different quotes. Consider installing a system that meets 90-100% of your annual usage.

Tesla may have a great price, but their prescriptive (cookie cutter) approach may not work in your case. Due to the limited roof space, you may find it better to have a third party install solar first to maximize your solar system. Then have Tesla come in to later to install Powerwalls. Typically this approach is more cost effective than having a third party do it all.

Also, be mindful on sharing personal information online. If possible, redact some information on the image you attached.

I see it. I do not see an edit button to upload a different image.

 

[Daniellane]

All,

I've been researching lots, and settled at Tesla's medium sized package with two PWs. But they came back and said they can only do a 3.78 kWh system due to roof shape. I asked them if they can add few more panels, and the second revision still came back to the same system because of setbacks etc. Tesla wouldn't budget. 12 panels and 2 PWs.

Another installer said they could do 21 panels, but that seems kinda fishy (see attached pic of my roof). Not sure how second installer can breach all the setbacks and codes. Unless its a bait and switch thing.

Would you guys/gals think this would be viable for my house? Tesla's 3.78 kWh system with two Powerwalls? Would the PWs even get used to the max capacity and usage?

Stats:

Home: 2400 sq ft home, two stories
Average kWh use monthly: 760 kWh
My provider in Central Valley Cali is Modesto Irrigation District, three tier kWh pricing.

Installed system 1 with one Powerwall late last year.
Installation Video link in this thread I posted. Link below:
Now We’re Really an All Tesla Family!