Cost of Tesla Solar Roof Tiles

[nativewolf]

adiggs is exactly correct, once they hit that price point then it is game over. The demand will swap anything being driven by utility grid regs such as net metering.

A million or so new homes a year I think, that much again in renovations.

 

[JOEV1]

Fully agree with AM Postings:
May I add that those slates / tiles / shindles would look equally good if wall-mounted (vertical on easterly and or westerly facing fasades) hence giving more power in morning and afternoon when the sun is low. Which applies in particular during winter months when the sun is generally at lower angles... and ... that´s the main argument, energy requirements (need for heating and lighting) are greater than during summer months.As I already have approx. 20 kWp of Panasonic panels on the roof and am very happy with, I have no reason/intention for the moment to remove, I might consider TESLA shindles for a Fasade-Installation.
EM has not said much to nothing ... in his presentation, about how those Slades are mounted and connected. Even less about the costs.
Hopefully we can get more information and technical data soon.[/QUOTE]

 

[ElectricTundra]

... if they are working with same supplier that does all the windshields for tesla you can bet their volume price is awesome.

I think for the Model 3 that supplier might be Tesla themselves. They've got their own group working on Tesla Glass for the 3. Given Elon's quickness to pull stuff in-house if he doesn't have confidence in outside suppliers they just may think that they can get in to the glass business or partner with someone.

 

[bluefuego]

When we had panels installed on our house, the solar company looked at which portions of our roof would receive enough sunlight at the proper angles to make the cost worthwhile. They were even able to determine what our ROI would be when we decided to add on the east facing roof of our garage.

So I have two questions:

1. Was any mention made of non pv versions of these roofing materials for less than ideal portions of a roof such as the north facing sides? I would assume these would be less expensive.
2. Are the louvres movable or fixed? I.E. how are different roof angles accommodated?

 

[Green Pete]

When we had panels installed on our house, the solar company looked at which portions of our roof would receive enough sunlight at the proper angles to make the cost worthwhile. They were even able to determine what our ROI would be when we decided to add on the east facing roof of our garage.

So I have two questions:

1. Was any mention made of non pv versions of these roofing materials for less than ideal portions of a roof such as the north facing sides? I would assume these would be less expensive.
2. Are the louvres movable or fixed? I.E. how are different roof angles accommodated?

1. Yes

2. Detail not yet revealed. Guessing fixed. However optimal angle of the sun in the markets they will go for first (USA and Europe) is pretty much the same everywhere minus northern scandaniavia, Hawaii and Alaska. So probably not an issue. Solar panels also lose a large amount of efficiency with small changes in angle (much less efficient aroundend of day than midday)

 

[bluefuego]

1. Yes

2. Detail not yet revealed. Guessing fixed. However optimal angle of the sun in the markets they will go for first (USA and Europe) is pretty much the same everywhere minus northern scandaniavia, Hawaii and Alaska. So probably not an issue. Solar panels also lose a large amount of efficiency with small changes in angle (much less efficient aroundend of day than midday)

Thanks.

Sun angle, yes. But doesn't the pitch of the roof matter as well? For instance flat top roof vs steep angles. I think pitches can vary up to 45 degrees.

 

[ecarfan]

So I have two questions:
1. Was any mention made of non pv versions of these roofing materials for less than ideal portions of a roof such as the north facing sides? I would assume these would be less expensive.
2. Are the louvres movable or fixed? I.E. how are different roof angles accommodated?

1. During his presentation Elon specifically mentioned that the Tuscan tile roof contained solar tiles and non-solar tiles in the same style. I do not recall him saying anything like that for the other three roof tile styles, but that doesn't mean they won't be available in a non-functional version. It would seem to make sense to offer them that way because almost every roof has areas where it is not cost effective to put solar on but you want it to match the solar part of the roof.
2. I'm not sure what you mean by "louvres". Do you mean the tiles? I would think they are fixed. But they would be laid flat on the roof structure so they will be at the same angle as the roof.

 

[bluefuego]

2. I'm not sure what you mean by "louvres". Do you mean the tiles? I would think they are fixed. But they would be laid flat on the roof structure so they will be at the same angle as the roof.

Elon mentioned that there were micro louvres in each panel - thereby making them look opaque from ground level but less so for the sun's angle. I was wondering if those louvres played any part in compensating for different roof angles. However, I admit that my assumption that roof angle being important may be incorrect. I mentioned it as I thought that our solar pv installers mentioned that they can adjust the installation racks to ideal angles for capturing the most sunlight.

 

[3Victoria]

It is possible the micro-louvres may be reflective, and therefore help capture sunlight. In addition, some mention was made of coatings, whuch again might increase efficiencies.

 

[electracity]

Elon mentioned that there were micro louvres in each panel - thereby making them look opaque from ground level but less so for the sun's angle. I was wondering if those louvres played any part in compensating for different roof angles. However, I admit that my assumption that roof angle being important may be incorrect. I mentioned it as I thought that our solar pv installers mentioned that they can adjust the installation racks to ideal angles for capturing the most sunlight.

How the louvers will function on different roof pitches is a good question. Perhaps they will produce two versions.

In photos of the Spanish roof house non-functioning tiles can be seen on the ridges as well as the 45 degree cuts. All tile solar tile types will need some ridge treatment and some cut pieces. An easy guess is that the Spanish tile will be the first sold, considering the california rollout.

 

[adiggs]

Being able to install the tiles as siding, again if the price can be made right ... I'd love to go with a glass siding product over the options I have available to me today. That'd be the end of paint, stain, and other siding maintenance that I don't want to do.

And heck - if the siding also generated some electricity to run my intensely electric house, I'm definitely in for that. (Yes - I realize that I won't be getting optimal output from wall mounted solar tiles; glass siding with or without solar solves some other problems for me I'd really like to get solved)

 

[winfield100]

remember, it is the cosine of the angle of incident light, however the sun moves all day and rooftops are "fixed angle" (so far, but who knows, maybe someone will invent a flat, non moving tracker)
(trackers give appx 30% gain, or throw on a few more panels, back in time 40 years ago when PV was really expensive)

There are world Solar angle calculators. to give you an idea of roof/panels/etc.
my ~23 degree angle (rise of 5 in run of 12) is best for summer as I am at ~40 degrees N latitude

An easy rule of thumb for appx 40 degree north or south latitude is subtract ~15 for an optimal tilt of around ~25 degrees to max out summer gain

(the earth tilts +/- ~23.5 degrees effectively as it goes around the sun or around ~47 degrees)
(there are LOTS of books and info over the last 40-50 years)

Solar Angle Calculator

 

[Green Pete]

It is possible the micro-louvres may be reflective, and therefore help capture sunlight. In addition, some mention was made of coatings, whuch again might increase efficiencies.

Not saying I know whether or not it will result in light from more angles hitting the PV cell in a meaningful way, but if they weren't reflective they wouldn't appear to have color from ground level. Fingers crossed.

 

[Green Pete]

remember, it is the cosine of the angle of incident light, however the sun moves all day and rooftops are "fixed angle" (so far, but who knows, maybe someone will invent a flat, non moving tracker)
(trackers give appx 30% gain, or throw on a few more panels, back in time 40 years ago when PV was really expensive)

There are world Solar angle calculators. to give you an idea of roof/panels/etc.
my ~23 degree angle (rise of 5 in run of 12) is best for summer as I am at ~40 degrees N latitude

An easy rule of thumb for appx 40 degree north or south latitude is subtract ~15 for an optimal tilt of around ~25 degrees to max out summer gain

(the earth tilts +/- ~23.5 degrees effectively as it goes around the sun or around ~47 degrees)
(there are LOTS of books and info over the last 40-50 years)

Solar Angle Calculator

This is certainly true of traditional PVs. But from an optical standpoint that's not an impossible hurdle to overcome. Its possible these have been designed to improve on that loss.

Roofs range from 12/12 pitches (12 declining feet/12 running feet) to... well 0/12 (0 declining feet/12 running feet). Most roofs tend to fall between 4/12 and 6/12. 12/12 would be 45 degrees and 6/12 would be 22.5 degrees. So most roofs will fall between 15 and 22.5 degrees, which as you pointed out is typically sub optimal. There is no way that Musk overlooked that major issue in the design process. There must be more tricks up his sleeve that we just haven't heard about, and if the merger is a shoe in, I doubt we will hear about until the first customer gets an install.

 

[AudubonB]

Maybe, Green Pete, but not necessarily. The reason is that for practical purposes, the traditional PV panels against which the Tesla Tiles presumably will be competing also are using the same roof angle upon which they would be laid. This makes the cost comparison or, perhaps better described, the cost-efficiency or the cost-output comparison, very very straightforward.

On the other hand, perhaps you are right. There are things one can do to and with glass....and I've been hoping that those little louvers 3M has in its plastic appliqué (which is, I've got to believe, embedded in or at worst under the glass - anything but atop) might either

* 1. Serve double duty, and at the same time they are presenting a nifty-keen-o French tile effect to the ground viewer, their orientation also is such that they snag that incident light and reflect or refract it so that it hits the receptors 90º on;

or

* 2. (the more complicated scenario) There is some electrochromic-like feature such that the louvers can be programmed to alter their angle as a function of the sun rays' angle. I can't for the life of me envision how this both could work at the same time as providing the tile-like appearance to the ground viewer, however.

 

[AudubonB]

Okay - that wasn't hard. I found some company material on the films. But I'm having a lot of trouble with our DSL right now, so I'll let others delve in and see what they can glean. The first link seems to be the most helpful, however.

http://multimedia.3m.com/mws/media/...ement-protection-films-industrial-prod-br.pdf
3M Electronics Manufacturing : Light Control Films
Display Enhancement Solutions - Protection and Light Control Films: Light Control Films: 3M United States

 

[Green Pete]

Maybe, Green Pete, but not necessarily. The reason is that for practical purposes, the traditional PV panels against which the Tesla Tiles presumably will be competing also are using the same roof angle upon which they would be laid. This makes the cost comparison or, perhaps better described, the cost-efficiency or the cost-output comparison, very very straightforward.

On the other hand, perhaps you are right. There are things one can do to and with glass....and I've been hoping that those little louvers 3M has in its plastic appliqué (which is, I've got to believe, embedded in or at worst under the glass - anything but atop) might either

* 1. Serve double duty, and at the same time they are presenting a nifty-keen-o French tile effect to the ground viewer, their orientation also is such that they snag that incident light and reflect or refract it so that it hits the receptors 90º on;

or

* 2. (the more complicated scenario) There is some electrochromic-like feature such that the louvers can be programmed to alter their angle as a function of the sun rays' angle. I can't for the life of me envision how this both could work at the same time as providing the tile-like appearance to the ground viewer, however.

point 1) Those panels are mounted on racks that are designed to optimized angel relative to the sun despite roof angle. (There is no way this hasn't come up in the R+D discussions at tesla)

point 2) going to agree with you. to much risk for weathering damage and having them function as pooling points for silt reducing solar efficiency.

point 3) this is what im betting on.

point 4) I find this highly unlikely, as I understand the louvers are plastic, and that seems like it would be a very manufacturing cost-ineffective solution even if technically viable. However, same concept applied to the cells of the PV panel seems feasible (athough still science-fiction to me). This would be very cool, but I think the louvers would interfere with the benefits of this effect.

 

[msnow]

Was on the phone with solar city yesterday. We had a PPA agreement ready for installation when the solar roof was announced. I told them we wanted to wait on the conventional solar panels until we got more information about the solar roof, as our current asphalt roof it 22 years old and will likely need replacement in the near future.

The woman on the phone gave me an admittedly wild ball park figure. She said, take the cost of a conventional solar installation and add 120% of the cost of a conventional roof. So, that puts us up in the 40-50k range, which is way, way more than just a roof replacement.

Of course, this would be a fantastic system if its longevity is as promised. But well out of our price range for now.

I had a similar conversation with my Solar City salesman. He had no idea what they would cost but said the availability "at best" is late 2017 and only to "select people". He said it would be more like 2018. Did you touch on that subject with your salesperson?

 

[AudubonB]

Pete:
Some roofs have their panels mounted on racks tilted to the optimum angle, but the far-cheaper "right on the roof" variety also exists in many, many places.

And rightly so, if I can describe the logic correctly - these numbers are for illustrative purposes only. If I need ten panels' worth of PV output, and if it is 30% more expensive to tilt-rack a set of 10 panels, and I have room on my roof to install 13 panels....then, ta da! - I'm ambivalent as to which route to go.

Now, some real-world experience. One of my three sets of panels in Alaska is ground-mounted (another is tower mounted; the third roof-mounted). As we're at 63ºN lat, our mid-summer incident angle is really steep, and our mid-winter incident angle is really, really steep! I can alter the panels' angle - either every single day or, less insanely, twice a year (say, at the equinoces). HOWEVER....what we have found by experimentation is that the day-long kWh intake, at mid-summer, is indistinguishable whether at "perfect mid-summer" or "dead mid-winter". And, since it's a pain-in-the-neck really kludgy operation to move the panels (I need use my excavator with bucket at full extension), several years ago I abandoned the process and just leave them at their very steepest mid-winter optimum all year round.

I have surmised that one of the reasons this works for me - but might not at 45º or 40º or 35º or 30º latitude is because of the crazy round-the-heavens track that our summer sun follows. That's another situation we have to contend with. Might be, maybe not (It's also partly the reason that our tower-mounted small array - just four panels - is on a tracker. But that's a different subject).

 

[Green Pete]

I had a similar conversation with my Solar City salesman. He had no idea what they would cost but said the availability "at best" is late 2017 and only to "select people". He said it would be more like 2018. Did you touch on that subject with your salesperson?

I find it wildly unlikely that a salesperson has any information right now about install cost of the system. That was likely (an unapproved by corporate) attempt to get you to buy now.