Tesla's "solar roof" Event - Hosted at Universal Studios

[Boourns]

I'm also concerned about the hail issue. Will my homeowner insurance premium skyrocket, or is damage to the tile system covered somehow by Tesla, either by warranty or in the form of a separate policy?

 

[JeffK]

They missed an opportunity to highlight the Tesla/Solar City combination.

Except the whole solar roof used with powerwall 2 thing you mean?

 

[JeffK]

I'm also concerned about the hail issue. Will my homeowner insurance premium skyrocket, or is damage to the tile system covered somehow by Tesla, either by warranty or in the form of a separate policy?

It'd be covered by your insurance. hail damages normal roofs too:

If the Solar Roof is around the same price as a normal roof then to insure it should be around the same... (one would think)

 

[HookBill]

I wonder if those people get the keep the powerwalls or.....

I hope tesla doesn't tear the roofs off of those homes after the presentation. That would be terrible. LOL

The homes are part of the Universal Studios movie set. The only people living there are Eddie Haskell, Wally and the Beav.

 

[mikevbf]

So interestingly, when you order the PowerWall you specify the size of your home to get an estimate...but they don't ask how many electric miles you drive a day! Surprised that's not included in their calculator, given that they're basically selling the solar + storage + electric vehicle solution.

I agree that that is strange. Maybe it is because they believe people will buy the batteries more for power backup than going off grid with their Tesla.

 

[Boourns]

It'd be covered by your insurance. hail damages normal roofs too...
If the Solar Roof is around the same price as a normal roof then to insure it should be around the same... (one would think)

Yes hail storms here in North Texas can demolish an asphalt shingle roof easily. If this is more fragile than a normal roof it will cost more to insure. Also, I think the website says the cost was comparable to a normal roof after energy savings. (Which not to get too off topic reminds me of quoting the price of a model S after gas savings). The problem is my ins company doesn't benefit from the energy savings so they are insuring a roof that costs more to replace.

 

[AudubonB]

Regarding hail:

Those glass shingles looked to me of the same order of thickness as a conventional PV panel. Now, I am sure one can find examples of hail damage to them but:

1. Our Alaskan PV panels have withstood 7 winters of horrific snow+ice events, and been exposed to temps of -58ºF. "Snow+ice" means as snow melts, the ice build-up along the panels' bottom edges is absolutely terrible - for the first several winters I really worried about their being torn apart.

2. Our Arizona PV panels have withstood three summers of +118ºF ambient shade temperatures - I have seen molten steel underneath their glass surfaces (I kid, of course). AND....this summer my mother-in-law reported they passed through thirty minutes of continual hail - including some monsters. Now, as a NWS APAID Weather Observer, I have been treated to many tales of exceptional weather, and I never have heard of a hailstorm lasting that long. At any rate, those panels also came through unscathed.

So, on the face of it, I am absolutely willing to believe that the (obviously tempered) glass these shingles (is that what they're being called?) are at least as up to hail and some amount of tree windfall damage as any other roofing. I hope they don't have to come up against a wayward returning 2nd stage booster; otherwise, we should be good.

 

[Gig103]

Yes hail storms here in North Texas can demolish an asphalt shingle roof easily. If this is more fragile than a normal roof it will cost more to insure. Also, I think the website says the cost was comparable to a normal roof after energy savings. (Which not to get too off topic reminds me of quoting the price of a model S after gas savings). The problem is my ins company doesn't benefit from the energy savings so they are insuring a roof that costs more to replace.

Obviously you'd have to check with your insurance before installing (I got an insurance quote on my car before placing my deposit), but I was coming here to post that I agree that 'cost of ownership' is not the same as 'cost', whether with fuel or a roof.

It's sad too, sort of OT, that Phoenix with its 300 days of sunshine, discourages solar - the power companies APS & SRP got permission to increase rates on solar homes to offset the loss of revenue those owners are sending to the power company. And it's common now to lease the devices, which owners don't consider how much a headache that can become when selling - I wouldn't buy a home that came with a solar lease that I had no say in or could negotiate!

 

[Skotty]

I agree that that is strange. Maybe it is because they believe people will buy the batteries more for power backup than going off grid with their Tesla.

As a utility friendly consumer, I want a Powerwall for load balancing; not to go off grid or for backup, but to not take advantage of the utility or rely on net metering.

 

[JeffreyY]

Anyone else expecting a new charger today?

Tweet from Elon end of Sept

Aiming for Oct 28 unveil in SF Bay Area of new Tesla/SolarCity solar roof with integrated Powerwall 2.0 battery and Tesla charger.

 

[jcee]

Except the whole solar roof used with powerwall 2 thing you mean?

What I mean is that they didn't come out and SAY "this is a result of Tesla and Solar City working together and is a great example of what we can do together". As I said, I don't see how this is done without them. If they don't spell it out, the media won't get it and it just felt like a missed opportunity to sell the merger.

 

[JeffK]

What I mean is that they didn't come out and SAY "this is a result of Tesla and Solar City working together and is a great example of what we can do together". As I said, I don't see how this is done without them. If they don't spell it out, the media won't get it and it just felt like a missed opportunity to sell the merger.

I wonder if investors don't approve the merger, they'll just pull solar roof... no soup for you!

 

[ohmman]

One thing I have never understood about putting solar on your roof is don't you want to shade your south side with deciduous trees to not heat up your house in the summer increasing the load on your air conditioner? To keep my trees I chose a ground mount system which is larger than what I need for my house alone, but not large enough for my house and Tesla. So the really nice looking panels are less useful, but maybe one or two of those power walls would serve nicely to add more ground mount solar, provide backup, while not needing any more inverters.

Shading your south roof with vegetation can be very valuable but depends on a great number of factors.

Most importantly, the current iteration of rooftop solar (not what was announced today) sits off of the roof on a mounting rack. The panels themselves shade the roof, while generating electricity at the same time. Absorbed heat is mostly vented through the air gap between the panels and the roof, but surely a small amount is passed to the roof. I think you are likely to net out in most cases.

Also, there are some locations where fire risk is great. The American West and Southwest are good examples. In these locations, we have the importance of "defensible space," which can but usually doesn't include trees.

There are locations (mine is one) where the annual heating load far outpaces the AC load. In this case, you generally want to maximize sun exposure. In fact, the downside to solar for me is that it shades the roof in the winter, when I'm not generating much. I recognize that deciduous trees are helpful in that they shed leaves in the winter, but shading is still very close to 50% at that point.

Deciduous trees close to a home can cause other problems, like gutter maintenance, fossil-fuel-powered leaf blower use, and expensive tree maintenance. Don't get me wrong - I'm a tree lover. I have a lot in my creek bed and on the perimeter of my property. I'm just done having them close to the house. My general feeling is that the passive shade of trees was a lot more useful prior to the advent of photovoltaics and modern home construction.

I'm always happy to sit in the shade of an oak and have a summer picnic, though.

 

[jcee]

I wonder if investors don't approve the merger, they'll just pull solar roof... no soup for you!

Seems like it's either a gutsy bet by Elon/Tesla or they already know it's going through. You don't make bets like that in big business...

 

[Ulmo]

Found from this article referenced by a tweet from Elon (bolding mine): These are Tesla’s stunning new solar roof tiles for homes

The current versions of the tiles actually have a two percent loss on efficiency, so 98 percent of what you’d normally get from a traditional solar panel, according to Elon Musk. But the company is working with 3M on improved coatings that have the potential to possibly go above normal efficiency, since it could trap the light within, leading to it bouncing around and resulting in less energy loss overall before it’s fully diffused.

Of course, there’s the matter of price: Tesla’s roof cost less than the full cost of a roof and electricity will be competitive or better than the cost of a traditional roof combined with the cost of electricity from the grid, Musk said. Tesla declined to provide specific pricing at the moment, since it will depend on a number of factor including installation specifics on a per home basis.

That is a misquote by the article about the cost. Here is Elon in the video about cost: Elon said in the video at 2:10 "... and actually have an installed cost that is less than a normal roof plus the cost of electricity." Here's the whole sentence, at 1:58:

The goal is to have solar roofs that look better than a normal roof, generate electricity, last longer, have better insulation, and actually have an installed cost that is less than a normal roof plus the cost of electricity.

Followup: another Elon tweet:

Elon Musk Verified account @elonmusk
Should mention that the Tesla solar roof is robust against any weather, incl heavy hail. Also, higher insulating value than a standard roof.
RETWEETS 333 LIKES 931 8:56 PM - 28 Oct 2016

 

[Sparky]

My so-far unasked questions:

1. The demo tiles Mr Musk held - I could not see anything like electronics on their backs. Obviously, all tiles need be interconnected and on down to the integrated Powerwall...but how?

2. How has Tesla placated every jurisdictions' fire departments, who seem to have a thing against their firemen getting electrocuted when penetrating roofs?

3. What are the efficiency #s of these panels?

Apparently there is a press Q&A occurring right now and I'm assuming we'll get answers to at least some of the Qs raised so far -

I spoke to a Powerwall engineer and Solar City engineer at the event.
Solar City guy: Although these tiles have active solar cells, these are not yet interconnected. The specific approach is TBD.
Fire codes are the same and they still have keep out zones as well, meaning some border portion of the roof must be tiles without power. That's 3 ft from the edge according to planning dept in my town.

I was also concerned about heat since there's no air gap. The Solar CIty guy said, yeah that's an issue but something that doesn't concern them too much.
I could not get an efficiency number. I talked to some 3M engineers who did the "louvering" film that makes the tiles opaque (so you don't see the cells from the street). They gave a 90% efficiency req for just that part. One of them was the guy who invented the film that computer screens etc use for privacy, so he should know. One of the 3M guys mentioned some stuff about the Model 3 interior instrument display but it seemed 3rd hand so I won't start any rumors here until I get some corroboration.

The slate roof was stunning. The Tuscan tile roof will have poorer efficiency due to curvature.

All in all, an above average event except for parking; on time, nice venue, excellent catering from Wolgang Puck . And I finally got to see a Model 3. Beautiful.

 

[ohmman]

I was also concerned about heat since there's no air gap. The Solar CIty guy said, yeah that's an issue but something that doesn't concern them too much.

So I mentioned this up in my post about tree shade above as well. However, in new construction there is a way to do this effectively. When we lived in Texas, we had a roof that was built with an air gap above the decking. At the apex of the roof, we had a vented cap all the way along the ridge, which allowed absorbed heat to be exhausted out. This would be an effective model to tweak for installation for these roof tiles.

 

[mikevbf]

Shading your south roof with vegetation can be very valuable but depends on a great number of factors.

Most importantly, the current iteration of rooftop solar (not what was announced today) sits off of the roof on a mounting rack. The panels themselves shade the roof, while generating electricity at the same time. Absorbed heat is mostly vented through the air gap between the panels and the roof, but surely a small amount is passed to the roof. I think you are likely to net out in most cases.

Also, there are some locations where fire risk is great. The American West and Southwest are good examples. In these locations, we have the importance of "defensible space," which can but usually doesn't include trees.

There are locations (mine is one) where the annual heating load far outpaces the AC load. In this case, you generally want to maximize sun exposure. In fact, the downside to solar for me is that it shades the roof in the winter, when I'm not generating much. I recognize that deciduous trees are helpful in that they shed leaves in the winter, but shading is still very close to 50% at that point.

Deciduous trees close to a home can cause other problems, like gutter maintenance, fossil-fuel-powered leaf blower use, and expensive tree maintenance. Don't get me wrong - I'm a tree lover. I have a lot in my creek bed and on the perimeter of my property. I'm just done having them close to the house. My general feeling is that the passive shade of trees was a lot more useful prior to the advent of photovoltaics and modern home construction.

I'm always happy to sit in the shade of an oak and have a summer picnic, though.

The shading the solar panels create in the summer makes some sense. In the summer the sun tends to be more straight over head concentrating its heat on the roof. However, I know a neighbor here in Vermont who has a very well insulated roof, but over glazed their south side and finds their house/studio way too hot in the summer. I actually do not have air conditioning, but plenty of south facing windows and plenty of deciduous trees on my south side. I call them my Vermont air conditioner because my house stays a nice temperature almost the entire summer.

In the winter I would guess you do not have to worry so much about the panels shading your roof. From my understanding the sun spends most of the time low in sky in the winter concentrating the heat through your windows not your roof. Please, any architect with greater passive solar knowledge feel free to chime in and correct us.

 

[AudubonB]

Thanks, Sparky, for anticipating my questions and finding someone there to answer them!

 

[Owner]

The shading the solar panels create in the summer makes some sense. In the summer the sun tends to be more straight over head concentrating its heat on the roof. However, I know a neighbor here in Vermont who has a very well insulated roof, but over glazed their south side and finds their house/studio way too hot in the summer. I actually do not have air conditioning, but plenty of south facing windows and plenty of deciduous trees on my south side. I call them my Vermont air conditioner because my house stays a nice temperature almost the entire summer.

In the winter I would guess you do not have to worry so much about the panels shading your roof. From my understanding the sun spends most of the time low in sky in the winter concentrating the heat through your windows not your roof. Please, any architect with greater passive solar knowledge feel free to chime in and correct us.

A lot of all of this can be addressed better with house design. When I built my house 10 years ago, I put in large overhangs over all the windows. They are around 6'? This allows no direct sun in the summer due to the high sun angle, and sun in the winter that warms the house. The natural trees here are oaks, and they don't offer huge amounts of shade and need to be away from the house for defensible space against fire.

Most people design their houses around their "fantasy home" not what really works in their given climate. I had A/C on once this summer and it was really due to the fire down south and opening up windows was not an option with that much air pollution.

My solar panels are over the garage in the North part of the house.