Solarglass install limitations?

[bayareaever]

My roof was denied in January ‘20 for Solarglass roof install for failing to meet minimum system size and ‘insufficient working space’.

I was never told what the minimum kw rating actually is, but according to my crude measurements I should be able to fit 4.5 - 6 kw on the main house and detached garage (5’ trench required). I am considering making another deposit to see if I get the same response, but I’d like to be informed in advance of what the actual install limitations are.

For v3 tiles, can those in the know comment about some of these limitations? I realize solarglass is more restrictive than panels in many ways (ie has to be landscape oriented, no continuous edges). Efficiency seems to be similar to ~10 year old panel technology so maximizing solar coverage is obviously important.

What are the required clearances from edges/ridges/valleys/vents for active tiles? What about minimum # of active tiles grouped together?

Any information/insight would be appreciated.

 

[jboy210]

Looking at our plan it looks like they are still using the 3 foot requirement on either side of the roof ridge, sides, etc..

 

[bayareaever]

Thanks for the reply, good to know. The Solar Roof phone rep told me 1’ clearances for active tiles, but I’m aware that she may have been misinformed or just making stuff up. Has anyone seen v3 installs with less than 3’ of clearance for active tiles?

1’ vs 3’ clearance requirements would likely make it or break it for my roof, and many others I’m sure. The 36” requirement was obviously created for solar panels and shouldn’t apply to solarglass, from I understand of the technology and the reasons for the setback requirements.

Another consideration is that my city didn’t enforce all the state codes when we built our addition, so maybe there’s hope. Then again, I doubt Tesla would knowingly violate state code even if the city permitting allowed.

 

[wjgjr]

Thanks for the reply, good to know. The Solar Roof phone rep told me 1’ clearances for active tiles, but I’m aware that she may have been misinformed or just making stuff up. Has anyone seen v3 installs with less than 3’ of clearance for active tiles?

1’ vs 3’ clearance requirements would likely make it or break it for my roof, and many others I’m sure. The 36” requirement was obviously created for solar panels and shouldn’t apply to solarglass, from I understand of the technology and the reasons for the setback requirements.

Another consideration is that my city didn’t enforce all the state codes when we built our addition, so maybe there’s hope. Then again, I doubt Tesla would knowingly violate state code even if the city permitting allowed.

I think 3' is correct, and I'm sure Tesla won't violate code knowingly (and I suspect the 3' rule is one Tesla just uses, even if you found a rare jurisdiction that didn't follow that.) My guess, based on your information, is Tesla may consider the size too small for them to want to do right now. We have an 8.2 kW system, and they were very clear that they would not do it if we didn't include the north-facing solar glass (which we debated because it does not give us the payback of the south-facing ones.) I don't know what their cutoff is, but it is possible they have decided for now that they won't install systems below a certain size.

 

[bayareaever]

I’m the OP. I didn’t mention that I’ve got a leased solar-city system installed in 2008 (I’m hoping to terminate the lease because the roof needs replacing sooner than later). The panels from 2008 have much less than 3’ clearances (not even 1’ in some places), making walking on the roof a very delicate maneuver. The panels cover ~1/2 the roof.

If/when I replace the roof, will the city grandfather in those clearances or am I SOL at that point? 3’ clearances would make reinstalling those panels impossible (or probably any others). Of course, if they were to grandfather me in, using Solarglass tiles is much better for all involved!

 

[jjrandorin]

I’m the OP. I didn’t mention that I’ve got a leased solar-city system installed in 2008 (I’m hoping to terminate the lease because the roof needs replacing sooner than later). The panels from 2008 have much less than 3’ clearances (not even 1’ in some places), making walking on the roof a very delicate maneuver. The panels cover ~1/2 the roof.

If/when I replace the roof, will the city grandfather in those clearances or am I SOL at that point? 3’ clearances would make reinstalling those panels impossible (or probably any others). Of course, if they were to grandfather me in, using Solarglass tiles is much better for all involved!

I am certainly no expert (not even close), but in the case of "grandfathering" what makes sense is to grandfather putting your existing equipment back in the existing location. Once you are changing equipment, or location, that is in general new construction, and would have to comply with new codes, right?

Also, I get the desire for the solar roof, but I dont see how any amount of "explaining" is going to make them sell you something they have already decided not to sell you.

It could be as simple as they decided your installation is not profitable enough for the amount of time / work on install (minimum size). Your roof size is not going to change unless you are doing an addition onto your home, so not quite sure how fruitful this is, other than as a thought experiement.

One can not make someone sell them something they dont want to sell....

 

[wjgjr]

It could be as simple as they decided your installation is not profitable enough for the amount of time / work on install (minimum size). Your roof size is not going to change unless you are doing an addition onto your home, so not quite sure how fruitful this is, other than as a thought experiement.

One can not make someone sell them something they dont want to sell....

In the end, I think this is what is going to come down to. We have seen on the solar roof side that Tesla is focusing on certain markets and excluding others (as a number of people got notices from Tesla recently cancelling their reservations.) And Tesla seems unwilling right now to put a solar roof on new construction. On the panel side, Tesla is selling based on specific array sizes.

No doubt all of this is intended to make things as efficient and profitable as possible as they ramp back up their solar division, but it does suck for those who don't fit into the box Tesla has defined. I would imagine at some point in the future they will relax some of their rules once they burn through the "easy" installs they are currently targeting and as they get more experience and find ways to reduce costs. But, whether that will be in a few months or a few years, who knows. It definitely sucks if you need a new roof now, as that is when solar glass really makes sense financially.

 

[bayareaever]

Tesla starts canceling Solar Roof orders after years of taking deposits - Electrek

One of the commenters from this article submitted multiple deposits after multiple denials and then finally got approved for a 4.4 kw system, so I guess persistence sometimes pays off. Then again, it’s just some guy on the internet so who knows!

My old system occupies virtually the entire street-facing side of my roof so definitely a fire code ‘disaster waiting to happen’. If they we’re to grandfather that in, it wouldn’t make much sense from a safety perspective.



QUOTE="jjrandorin, post: 4758612, member: 91471"]I am certainly no expert (not even close), but in the case of "grandfathering" what makes sense is to grandfather putting your existing equipment back in the existing location. Once you are changing equipment, or location, that is in general new construction, and would have to comply with new codes, right?

Also, I get the desire for the solar roof, but I dont see how any amount of "explaining" is going to make them sell you something they have already decided not to sell you.

It could be as simple as they decided your installation is not profitable enough for the amount of time / work on install (minimum size). Your roof size is not going to change unless you are doing an addition onto your home, so not quite sure how fruitful this is, other than as a thought experiement.

One can not make someone sell them something they dont want to sell....[/QUOTE]

 

[bayareaever]

Tesla starts canceling Solar Roof orders after years of taking deposits - Electrek

One of the commenters from this article submitted multiple deposits after multiple denials and then finally got approved for a 4.4 kw system, so I guess persistence sometimes pays off. Then again, it’s just some guy on the internet so who knows!

My old system occupies virtually the entire street-facing side of my roof so definitely a fire code ‘disaster waiting to happen’. If they we’re to grandfather that in, it wouldn’t make much sense from a safety perspective.



QUOTE="jjrandorin, post: 4758612, member: 91471"]I am certainly no expert (not even close), but in the case of "grandfathering" what makes sense is to grandfather putting your existing equipment back in the existing location. Once you are changing equipment, or location, that is in general new construction, and would have to comply with new codes, right?

Also, I get the desire for the solar roof, but I dont see how any amount of "explaining" is going to make them sell you something they have already decided not to sell you.

It could be as simple as they decided your installation is not profitable enough for the amount of time / work on install (minimum size). Your roof size is not going to change unless you are doing an addition onto your home, so not quite sure how fruitful this is, other than as a thought experiement.

One can not make someone sell them something they dont want to sell....

[/QUOTE]

I’m the OP. I got good news yesterday- after having my roof denied twice by Tesla for Solarglass tiles (November ‘19 and June ‘20), now they’ve accepted it! (see design picture). It is a smaller 4.74 kw system given the roof size/complexity, which I assume is why they denied it previously. Presumably they are going to take on these sorts of projects more as they expand installations.

This reservation was made ~4 months ago and I just received the design, with installation tentatively not available until spring/summer next year. They must have a ton of demand, plus the wet winter months are always trickier to schedule. I’m in the SF Bay Area.

 

[getakey]

didn't go back to the beginning of this thread, but wouldn't it be better to go with panels for a small system size?

 

[bayareaever]

Not considering price (I need a new roof anyway). This roof, after the FTC, is only marginally more expensive than a normal composition shingle roof (which I’ve gotten several quotes on).

I think that’s why Elon has been saying this product will be huge. When a normal roof and a solar roof have similar costs, who the heck is going to choose a normal roof??

In terms of aesthetics, there’s really no comparison with installed panels.

Presumably, roof life will be longer than composite shingles.

Also, from what I understand, because of fire code, much of my south facing roof is off limit to panels. That being said, Tesla hasn’t applied for a permit yet, so hopefully there’s no snags there.

 

[bayareaever]

Not considering price (I need a new roof anyway). This roof, after the FTC, is only marginally more expensive than a normal composition shingle roof (which I’ve gotten several quotes on).

I think that’s why Elon has been saying this product will be huge. When a normal roof and a solar roof have similar costs, who the heck is going to choose a normal roof??

In terms of aesthetics, there’s really no comparison with installed panels.

Presumably, roof life will be longer than composite shingles.

Also, from what I understand, because of fire code, much of my south facing roof is off limit to panels. That being said, Tesla hasn’t applied for a permit yet, so hopefully there’s no snags there.

They almost doubled the number of active upon my request! If you want a big solarglass roof system, apparently it pays to ask for a redesign. I’m not sure why they didn’t max it out initially but oh well...

 

[jboy210]

They almost doubled the number of active upon my request! If you want a big solarglass roof system, apparently it pays to ask for a redesign. I’m not sure why they didn’t max it out initially but oh well...

Check the projected annual yield and see how much it changed from your previous design. You have a lot of panels facing North, that will not produce much if any in the winter months.

We have the same plus shading from a tall tree and are seeing 5-6 kWh/day this time of year. But, in summer we can see 80+ kWh/day. Our system is 12.75 kW.

 

[wwhitney]

Check the projected annual yield and see how much it changed from your previous design. You have a lot of panels facing North, that will not produce much if any in the winter months.

True, but the effect depends heavily on the roof slope. Using PVWatts with Berkeley, CA as the location for weather data and latitude, here are the ratios of annual production estimates on north facing versus south facing panels for various slopes:

1 in 12: 91%
2 in 12: 84%
4 in 12: 72%
6 in 12: 61%
8 in 12: 54%

Cheers, Wayne

 

[jboy210]

True, but the effect depends heavily on the roof slope. Using PVWatts with Berkeley, CA as the location for weather data and latitude, here are the ratios of annual production estimates on north facing versus south facing panels for various slopes:

1 in 12: 91%
2 in 12: 84%
4 in 12: 72%
6 in 12: 61%
8 in 12: 54%

Cheers, Wayne

Wayne, how do your read these numbers? That is, is the 1 in 12 mean 1 north panel out 12 south, or is that roof pitch or ??

Also, wondering if that this is a solar roof that matters. They can put a run of active tiles in pretty tight spaces. Some of our runs are 2 rows of active, so 24" active and tucked in the shadow of dormers, chimney, etc. See picture taken at 12:30 PM. These small runs on the North facing side pretty much stay in those shadows from late November till February.

 

[wwhitney]

That is, is the 1 in 12 mean 1 north panel out 12 south, or is that roof pitch or ??

Roof pitch.

Wayne

 

[wjgjr]

I could see where things like dormers could be an extra issue (and it would affect panels too if they were put there.) Depending on how close the dormers are, they could cause shadow issues even in summer (and, since solar roofs don't have shingle-level optimization, I wonder how much it affects production, even assuming use of MPPT.)

But, even without that, as @wwhitney posted, just the slope of the roof can make a big difference. Other coast from Berkley, but only about 1° of latitude north, and PVWatts estimates ~52% production on the near-north (7°) slope vs. the south slope, with an 8/12 (34°) roof. But most of that difference is now - in December, the north face has only 15% of the production of the south, while in summer it is 94%. It's just the reality that with the sun only getting up to about 29° at local noon on the winter solstice, the north-facing slope is not going to get much direct sunlight in the winter months.

For OP, and as a general comment, so far the Tesla estimates for annual production seem to be on track. That said, I used PVWatts to get monthly numbers to use to try and convert the Tesla annual number into monthly values, and December looks like the first month I will be below the estimate. Whether this is shading, weather, or something else, I am not sure.

 

[bayareaever]

Just revising this thread. My solar roof journey has been long and I’m now finally in the first week of install. Most of the sentiment has been quite negative lately (at least on this forum) but I want to mention how great the install team has been so far. I realize the sentiment has a lot to do with the price increase, which I managed to avoid (my advisor said I was the only exception he’d seen so I obviously got very lucky). there were also other extenuating circumstances I won’t detail here that were a factor. I personally hope Tesla is ultimately held responsible for broken contracts, but that’s a different subject.

Anyway, the tear-off has revealed two asbestos pipes sticking out from the attic which have to be professionally removed before those roof sections can even be touched. The scheduling team has been very accommodating with the unexpected delay and the work that’s been done thus far looks high quality. Luckily there’s no rain coming, or I’d be pretty screwed.

My point is, for those that can afford it and don’t need a new roof immediately (ie you can wait several months to a year for install), I highly recommend it based on my experience thus far.

Based on the manpower that’s required, I’m not surprised the price went up, especially combined with increased material cost.

 

[holeydonut]

Lol, you'll go down in the books as the last happy solar glass customer on TMC.

PS, get some pictures of the install

 

[jboy210]

Lol, you'll go down in the books as the last happy solar glass customer on TMC.

PS, get some pictures of the install

We are happy with ours.