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

Solarglass Roof install set for Feb 16-Mar1

jboy210

Supporting Member
Dec 2, 2016
5,089
3,156
Northern California
Yeah!! Inspection passed!

It was sort of anti-climatic. The Tesla guy came early and spent 20 minutes putting stickers on everything. Inspector rolled up and compared his paper to the Tesla guy's. Made sure the boxes were on outside and powerwalls in garage. Done in 10 minutes.
 

wjgjr

Active Member
May 11, 2020
1,209
947
Silver Spring, MD
Yeah!! Inspection passed!

It was sort of anti-climatic. The Tesla guy came early and spent 20 minutes putting stickers on everything. Inspector rolled up and compared his paper to the Tesla guy's. Made sure the boxes were on outside and powerwalls in garage. Done in 10 minutes.

Glad it all passed. I think some of the inspections have maybe gotten a bit easier to pass with coronavirus as inspectors either don't go into homes at all or minimize the amount of time in/around the home and others.
 

jboy210

Supporting Member
Dec 2, 2016
5,089
3,156
Northern California
Glad it all passed. I think some of the inspections have maybe gotten a bit easier to pass with coronavirus as inspectors either don't go into homes at all or minimize the amount of time in/around the home and others.

True. We have a requirement to have a smoke detector in every room and CO detector on every floor. They had me sign a piece of paper saying we met this requirement. Previously they would have gone inside and walked around to check for compliance.
 

wjgjr

Active Member
May 11, 2020
1,209
947
Silver Spring, MD
True. We have a requirement to have a smoke detector in every room and CO detector on every floor. They had me sign a piece of paper saying we met this requirement. Previously they would have gone inside and walked around to check for compliance.
Yep. We have that too. A few years back, with our new furnace, the inspector absolutely checked that (and our installers at the time installed a CO detector needed for compliance.) This time, though Tesla did verify we had the CO detectors when they installed, nobody checked, or even asked us, in this case. (And, I think we may technically be out of compliance as they may now require 10-year batteries, which we don't have yet.)
 

jboy210

Supporting Member
Dec 2, 2016
5,089
3,156
Northern California
Yep. We have that too. A few years back, with our new furnace, the inspector absolutely checked that (and our installers at the time installed a CO detector needed for compliance.) This time, though Tesla did verify we had the CO detectors when they installed, nobody checked, or even asked us, in this case. (And, I think we may technically be out of compliance as they may now require 10-year batteries, which we don't have yet.)

Last time our detectors went out of date I replaced them with Nest Protects. They seem to work well and actually speak to you. Saying things "Fire detected upstairs (or whatever name you select)" or "replace battery in upstairs detector". Much better than just beeping and send you searching your house for which of detectors is beeping.
 
  • Like
Reactions: preilly44

Tk18

Member
Jun 6, 2020
22
4
Bay Area
A little more info.


  1. Roof is producing and Powerwalls are charging. (We weren't using grid when picture was snapped.)
  2. Looks like the City of Pleasanton inspection will be done over a video chat. Tesla will handle that and send one of their inspection team to deal with it. I hope they get it done soon and so does Tesla, because we do not pay them until that inspection is passed.
  3. They said they did not think PG&E would come out to the house to inspect before giving us PTO.

View attachment 528675
What is the size of the system? What is the peak production (June 21 at solar noon) and max energy produced in a day? How much did Tesla say you would produce in a year?

a lot of us are seeing numbers that seem lower than expected, so it would be good to collect/report data so we can all compare.
 

wjgjr

Active Member
May 11, 2020
1,209
947
Silver Spring, MD
What is the size of the system? What is the peak production (June 21 at solar noon) and max energy produced in a day? How much did Tesla say you would produce in a year?

a lot of us are seeing numbers that seem lower than expected, so it would be good to collect/report data so we can all compare.
While the Tesla number matters, I think the other numbers provide an incomplete picture since a lot of things, from location (particularly latitude, but also weather patterns) to panel layout (including roof pitch and azimuth) can affect the ratio of peak production to total production and the ratio between summer and winter solstice.

To put some numbers behind what I previously mentioned, I went to PVWatts and got their data, which indicates an annual production of 8,839 kWh for my system. This compares to the estimate Tesla provided me of 7,876 kWh, so Tesla is giving me an estimate that is about 89.1% of the PVWatts estimate. Further, PVWatts breaks this down by month, including (all numbers in kWh) 1,037 for June and 1,045 for July. This would suggest Tesla estimates of about 924 and 931 for June and July, respectively. My actual production numbers (*see important notes below) are 976 and 1061 for the two months. While it is way too early to declare success, so far, it looks like performance is as expected - both numbers are tracking above what I believe Tesla expected and are actually very close to PVWatts (certainly within their margins of error.) I have not done things like compare cloud cover/rain data with historical averages to see how much that might have impacted production.

I think this type of calculation is helpful because it takes away a bit of the concern about focusing on peak numbers (which I admit concern me at times - probably should not be staring at the app so much) or trying to extrapolate too much from limited data. And PVWatts (and Tesla) numbers should be taking into account all the issues noted above that make a single measurement hard to compare across installations. PVWatts has the nice advantage of providing monthly numbers, so you can perhaps detect sooner than a year if something seems wrong with your production.

*The important notes on the numbers are that I did not receive PTO until mid-July. So, the June number reflects 30 days of off-grid operation (first day I started running off-grid was 5/31, which is why I started with June data,) and the actual number is probably just a bit higher as I didn't always have the system running sunrise to sunset, and, on occasion, production stopped due to a full PW. In July, I also had a 5-day span where I was not at my house and did not operate, so I multiplied my actual production by 31/26 to reflect this. Because of all of this, I would consider August the first month I can make an official comparison, but I think the June/July numbers are pretty close and are actually slight underestimates of what I could have produced running on-grid 24/7.
 

Tk18

Member
Jun 6, 2020
22
4
Bay Area
While the Tesla number matters, I think the other numbers provide an incomplete picture since a lot of things, from location (particularly latitude, but also weather patterns) to panel layout (including roof pitch and azimuth) can affect the ratio of peak production to total production and the ratio between summer and winter solstice.

To put some numbers behind what I previously mentioned, I went to PVWatts and got their data, which indicates an annual production of 8,839 kWh for my system. This compares to the estimate Tesla provided me of 7,876 kWh, so Tesla is giving me an estimate that is about 89.1% of the PVWatts estimate. Further, PVWatts breaks this down by month, including (all numbers in kWh) 1,037 for June and 1,045 for July. This would suggest Tesla estimates of about 924 and 931 for June and July, respectively. My actual production numbers (*see important notes below) are 976 and 1061 for the two months. While it is way too early to declare success, so far, it looks like performance is as expected - both numbers are tracking above what I believe Tesla expected and are actually very close to PVWatts (certainly within their margins of error.) I have not done things like compare cloud cover/rain data with historical averages to see how much that might have impacted production.

I think this type of calculation is helpful because it takes away a bit of the concern about focusing on peak numbers (which I admit concern me at times - probably should not be staring at the app so much) or trying to extrapolate too much from limited data. And PVWatts (and Tesla) numbers should be taking into account all the issues noted above that make a single measurement hard to compare across installations. PVWatts has the nice advantage of providing monthly numbers, so you can perhaps detect sooner than a year if something seems wrong with your production.

*The important notes on the numbers are that I did not receive PTO until mid-July. So, the June number reflects 30 days of off-grid operation (first day I started running off-grid was 5/31, which is why I started with June data,) and the actual number is probably just a bit higher as I didn't always have the system running sunrise to sunset, and, on occasion, production stopped due to a full PW. In July, I also had a 5-day span where I was not at my house and did not operate, so I multiplied my actual production by 31/26 to reflect this. Because of all of this, I would consider August the first month I can make an official comparison, but I think the June/July numbers are pretty close and are actually slight underestimates of what I could have produced running on-grid 24/7.


Of course, but Tesla knows all of the parameter of the project when they are suppose to come up with the project proposal. If they tell you "with this system you will get 10MWh per year, and this is conservative and we generally see a lot more than what we quote" you buy based on that.

Thank for the PVWatts reference: I entered the data for each side of the roof to be "as precise as possible" (given that there are a lot of parameters other than pitch, azimuth and array size in kw based on ration of tiles... that I don't really know), and summed them up and got 12486kwh for the year compared to the 10773 quoted by Tesla... Based on that ratio, July should have been 1363kwh... and it seems it's been 1015kwh... 25% below... a pretty big difference in my opinion...

And the difference would be even worst if I described the ideal installation in PVWatts instead of using the real tile ration as installed by Tesla.

It looks like we started about the same time except our utility company was super suportive and gave PTO the day after permit approval... except, because of the polarity inversion issue, during the whole June we were producing only 1.9kw peak and 15kwh per day until July 1st when Tesla finally "fixed" the polarity mistakes... (although it is still unclear to me how I can be sure there are no more errors since we have so many individual groups of tiles. Not sure either if the polarity inversion could have damaged something.So I only have the number for the month of July... (and it does not help that the app does not report the right numbers because the sensors were most likely installed improperly...)
 

Tk18

Member
Jun 6, 2020
22
4
Bay Area
Of course, but Tesla knows all of the parameter of the project when they are suppose to come up with the project proposal. If they tell you "with this system you will get 10MWh per year, and this is conservative and we generally see a lot more than what we quote" you buy based on that.

Thank for the PVWatts reference: I entered the data for each side of the roof to be "as precise as possible" (given that there are a lot of parameters other than pitch, azimuth and array size in kw based on ration of tiles... that I don't really know), and summed them up and got 12486kwh for the year compared to the 10773 quoted by Tesla... Based on that ratio, July should have been 1363kwh... and it seems it's been 1015kwh... 25% below... a pretty big difference in my opinion...

And the difference would be even worst if I described the ideal installation in PVWatts instead of using the real tile ration as installed by Tesla.

It looks like we started about the same time except our utility company was super suportive and gave PTO the day after permit approval... except, because of the polarity inversion issue, during the whole June we were producing only 1.9kw peak and 15kwh per day until July 1st when Tesla finally "fixed" the polarity mistakes... (although it is still unclear to me how I can be sure there are no more errors since we have so many individual groups of tiles. Not sure either if the polarity inversion could have damaged something.So I only have the number for the month of July... (and it does not help that the app does not report the right numbers because the sensors were most likely installed improperly...)

Actually: I think I should count in the PW numbers too, so for July it was 1216, so just 11% off... Still not small.
(I thought the inverters would keep the numbers for the month, but it is only the current month, so August now... and the app reports incorrect solar production numbers, and maybe some others...)
 

wjgjr

Active Member
May 11, 2020
1,209
947
Silver Spring, MD
Actually: I think I should count in the PW numbers too, so for July it was 1216, so just 11% off... Still not small.
(I thought the inverters would keep the numbers for the month, but it is only the current month, so August now... and the app reports incorrect solar production numbers, and maybe some others...)
11% low is definitely concerning. If this was a long-running system, I would say it certainly could happen in a given month due to weather though I do not know what yours was like in comparison to a normal July. However, it being the first month you have had "normal" operations plus the issues you have had with the install add reason to be concerned. The incorrect app data issue you mention sounds like something Tesla may be able to fix with a support call - I think others have seen it (both roof and panel installations.) It might also be a good time to at least ask them about the July numbers. However, I expect they will say it is running normally and to just wait for more data.
 

About Us

Formed in 2006, Tesla Motors Club (TMC) was the first independent online Tesla community. Today it remains the largest and most dynamic community of Tesla enthusiasts. Learn more.

Do you value your experience at TMC? Consider becoming a Supporting Member of Tesla Motors Club. As a thank you for your contribution, you'll get nearly no ads in the Community and Groups sections. Additional perks are available depending on the level of contribution. Please visit the Account Upgrades page for more details.


SUPPORT TMC
Top