Tesla Solar Roofing

[vinny11950]

Tesla's new solar roof shingles look sweet, if they perform as advertised. That added to their new home battery packs and you got a bigger solution to daily energy needs.

https://www.bloomberg.com/news/articles/2016-10-31/no-one-saw-tesla-s-solar-roof-coming

 

[iamlucky13]

That's interesting. I assumed SolarCity's new roof system would go for low costs via a modular panel system that would flush mount to the sheathing. They're going instead for the premium roofing tile look. This is a product for high end homes.

For the efficiency claims, based on my limited exposure to textured optics, I very strongly suspect when they say "2% efficiency reduction," they actually mean 2 percentage points (eg: 15% to 13%, not 15% to 14.7%).

They've got a quick video on their website showing off a ball bearing being dropped on their tempered glass solar tile compared to normal roofing tiles:
(broken link removed)

 

[peakbagger]

The devil is in the details. That said its a nice strategy, sell into high end homes. Given the tiles construction they should also be "fire proof". The one thing not discussed is the interconnecting wiring between panels and the inverter which has been an issue with the majority of prior systems. Some of the prior systems required terminating hundreds of wires in the attic and the electrical labor was several times higher than the labor to actually install the roof. It will come down to how big of sheet of the product can be installed as a unit and if the interconnecting wiring can be factory installed so that each sheet can have a reasonable output to match it up to a reasonably sized microinverter. The potential for being able to melt ice is also intriguing, It will be interesting to see how much net power is produced on shorter winter days when the roof heating is needed the most. Long term maintainability is also something I am curious about. What happens if one of the solar panel modules stops working, how can wiring and inverter be accessed? Roof sheathing is generally required in the high wind zones to keep the building from racking, so access from the attic is not possible.

 

[vinny11950]

All good questions. Being it is a sales pitch, there are probably a lot of issues right now. But the strategy is clear: Sell the solar panels and batteries for the home, and the electric car, maybe even sign a contract with Tesla to sell your extra power back to them and then they sell it again. Tesla is trying to position itself as a one stop shop for home electricity, electric cars, and electric utility company (far off right now, but it sure looks like it). Add in all the benefits of being able to smart program all the components to work to greater efficiency, and they may well do it.

And selling to the high end is the smart strategy because wealthy people have no problem plunking down for a system and then waiting for delivery, like they do for Tesla cars still in development. As they build out the system, the prices will come down to take a bigger market share.

I can see it already: Walk into HD or Lowes and a Solarcity rep tries to sell you the new shingles. And by the way, if you do buy it, you get a discount on a Tesla electric car.

 

[peakbagger]

I hate being the skeptic on these concepts but the reality is some folks actually believe the hype. I guess in this case I am more of a potential Chevy Bolt customer than a Tesla customer. Tesla is definitely the flagship for developing the technology but much of the funding is coming out of wall street investors that are ignoring numerous warning signs that the financials don't line up with the promises. Chevy most likely loses a lot of bucks on Volts and I expect the Bolt but its the cost of doing business after the US bailout.

Unless the US government passes and implements stiff carbon taxes on fossil fuels, there just currently is no economic justification for electric vehicles except as a offset for the sale of trucks and SUVs. Tesla offsets a big chunk of the build costs of each car by selling credits to other companies that don't have electric vehicles.

Powerwall sales to date are mostly aligned to people with unreliable power. Green Mountain Power in VT offers them as boutique item but have admitted that they are not cost effective given the current rate structure. Change the rate structure to allow incentives for short term peak shaving and they may have a place but in most cases utility scale batteries are far more cost effective for the same purpose..

Standard solar panels are cheap to build with massive infrastructure in place to build them and numerous companies willing to run at a loss hoping they may avoid the fate of numerous other failed companies in the race to low cost. I just don't see how a custom design solar tile is going to be anywhere competitive with standard PV in the short to medium term. Standard panels are ugly to many but they are quick to set up and cheap. I don't see Tesla panels being used in retrofits and if the US wants PV on residential homes the retrofit market for existing housing stock is the place to be.

Sure there are going to be boutique buyers and creative financing arrangements to hide the initial cost but I expect that market for the triple play of PV, storage and transport is limited unless a government steps in and stacks the deck. I don't dump on anyone who is doing it as I realize that there are other reasons than economics but given the resistance I get from most non "geeks" they really are hard pressed to justify a 10 to 30 K investment to reduce their power bill. Add in obscene incentives like one of the forum posters is getting on an install and I am glad to recommend grabbing the cash while its there but realize someone is paying those subsidies as it sure isn't coming out of Duke's bottom line.

 

[iamlucky13]

I have to admit, I've had many of the same thoughts peakbagger voiced, but sometimes I feel like I'm being a perennial wet blanket on alternative energy topics.

That said, SolarCity trying out a boutique product in the market is a risk mainly to Musk and his fellow investors, not a major policy driver, so it's the kind of matter I can be content to quietly watch unfold. Besides, there are interesting aspects to it, in particular how well they apparently mimic the appearance of existing building materials, and I'm very curious how these actually install to the roof and wire together.

 

[begreen]

Yes I was wondering about the installation process too. I would assume they will come in sheet panels, but not sure. Also wondering if they have dummy panels for the north sloping surfaces of the house at a notably reduced price.

Chevy most likely loses a lot of bucks on Volts and I expect the Bolt but its the cost of doing business after the US bailout.

Note: according to GM Authority the 2016 Volt is profitable. The claim is that they managed to shave off $10K off the cost of the 1st gen car. Seeing that so far they have not reduced the price of the selling vehicle that should change the bottom line. However, the impact of the Bolt on Volt sales will be interesting.

 

[iamlucky13]

I assume dummy panels are a necessity. They need matching blanks not just for roof slopes that aren't deemed worth the cost of adding solar, but also to be cut to fit edges and to match hipped corners or other odd angles.

 

[EatenByLimestone]

He said something like roof minus electricity equals the cost of a conventional roof. If the cost of the shingles follows the cost of PV panels, in 3-4 years he will be saying this roof will pay for itself. Then continue to pay you for 10 years.

 

[woodgeek]

I talked to the guy who ran the Dow solar shingle program a few years back. Those things were flexible and walkable, with a clear vinyl base (IIRC) and thin film CdTl cells integrated. Their goal was to have something that a roofer could install with a regular nailer (after a 10 min training video, that they produced in like 10 languages), with the electrical working with a snap together edge to edge connector.

The guy talked about how roofers are MUCH cheaper per square foot than solar installers....that is what drives the whole concept.

I think that program is dead now, b/c it was based on the CdTl cells, and this was before the cost of Si cells fell through the floor.

My point here is if they have a product that installs like any other roof tile, that roofers can install/repair, and the electrical is there for free with some dead simple interconnection, then they have a business. Even then, rigid tiles are not common in the midwest or northeast, so finding installers could be hard...but those are probably not the target market regions.

 

[woodgeek]

Unless the US government passes and implements stiff carbon taxes on fossil fuels, there just currently is no economic justification for electric vehicles except as a offset for the sale of trucks and SUVs. Tesla offsets a big chunk of the build costs of each car by selling credits to other companies that don't have electric vehicles.

Sorry, can't let this go. I want to see your evidence for this statement. I don't want to argue Tesla's finances so much (they have good gross margins, and excellent market penetration in the luxury car segment, and are scaring the pants off the other luxury makers who are seeing their gross sales in the US/EU fall). Total cost of ownership for first generation pure battery EVs is comparable or lower than ICE vehicles in the same class. And second generation, longer range BEVs with cheaper (present day) batteries are even lower TCO.

And putting costs aside, many folks that test drive EVs prefer the driving dynamics, comfort, or like the lower maintenance schedule, so customer demand is there. As battery prices continue to fall, BEVs will simply become better and cheaper than ICE cars, and they will be unstoppable.

2016 EV sales in the US are at record levels, despite cheap gas (crossing 1% of new sales this quarter). EU-wide average market penetration is surging past the US rate (aided by their gas taxes), and China is on track to add 500,000 EVs to its car fleet just this year.

 

[peakbagger]

At some point in the future, battery technology may have the required power density, to replace ICEs but we aren't there yet. Sure there is niche market for new heavily subsidized electric vehicles. CA, a fairly large market has a EV mandate that forces manufacturers to produce EV vehicles and sell them at a loss or pay some other firm for credits (Tesla). There is a fairly large subsidy in place in most areas in that EVs do not pay their way to keep the road system maintained as the vast majority of the road work is paid by fuel use taxes. Sure this could change by going to "pay per mile" but there is significant resistance to this concept. EVs don't buy fuel so they don't contribute to maintaining the roads yet they do the same damage as an ICE vehicle. I cant comment on Chinese market penetration but expect its a result of policy probably related to urban pollution. No doubt for city commuting, EVs have their place but in most cases, there are one or two ICE vehicles sitting next to them in the driveway. In an affluent household, multiple vehicles for different tasks is a choice and a lifestyle statement. Tesla at some point may go down market but the current demographics are affluent individuals who drive them for image. not for cost savings.

A fairly key indication that EVs are a niche market in the US is the market for used EVs. Their overall depreciation is noticeably higher than ICE engine vehicles. Tesla is an exception as its a niche product in short supply so there is a demand that the used market fills. Its also quite telling that many of the manufacturers sell EVs only in CA and sell them at loss, most firms decide they will cut their losses and write a check to Tesla for EV credit.

I personally live in a rural area with a cold climate, I and a lot of my neighbors have to routinely drive on trips that exceed the real versus advertised range of EVs. Folks in sunny CA don't realize that the optimistic ranges publicized assume minimal or no cabin heat or AC. The rare individuals I have met with EVs in my area admit that they have to reduce their range by 10 to 20% to account for running the heat and decreased battery performance due to lower temperatures. Sure I can pick up a 30K vehicle for the times I go shopping and have it take up space in my garage but given that in addition to the upfront cost I get hit yearly with yearly high excise taxes based on the sticker price, not the rebated price, its hard to justify when I have 12K fiesta that gets a real world 40 MPG running at typical highway speeds of 75 mph.

The range issue is significant, despite the now forgotten PR that Tesla was going to roll out a network of battery change out stations where a driver would swap a depleted battery with a charged battery the reality is that they switched to deploying a series of charging stations along limited major highways. Sure they make great PR but most drivers value their time over cost and sitting in line at a charger station waiting for a slot and then waiting the requisite charging period would start to get old real quick. Sure with enough dollars thrown at installing infinite charging stations, the time lost waiting for a charging slot goes away but the time to charge doesn't. The used Volt market reportedly backs that up as a majority of fleet Volts have many miles of operation with the backup ICE engine and few on strictly charger operation. I realize that there is minority of folks who take pride in only running on electricity but expect the majority value time and hassle over the environment.

I realize that public policy can shift any market, Europe elected to go diesel by charging much higher excise taxes on gas vs diesel. Some urban areas with significant pollution issues have outright banned or limited ICE engines thus encouraging EVs. CA allows EVs in HOV lane, I expect that drives some folks to buy a Tesla. Arguably there is no such thing as a free market and many will legitimately argue that the fossil industry is heavily subsidized with both money and blood. I just don't see that given that a large majority of the US population don't believe in anthropogenic climate change and are buying SUVs and trucks at record levels I don't see a big shift in public policy required to shift the US economy to EVs.

I am an engineer by profession and have plenty of "green" in my professional background including PV, alternate fuels, wind, CHP, CNG biomass and deployment of the first commercial cellulosic based renewable fuel oil heating application in the US. Most if not all of these technologies are technically fascinating yet only make sense financially with heavy upfront and ongoing subsidies. Fundamentally its still a lot cheaper to drill a hole in the ground and extract fossil fuel. Given the current indication that extraction of the current proven fossil reserves will put the CO2 levels far into the danger zone I ultimately feel that carbon taxes will inevitably appear and at that point EVs will make economic sense but until then they will remains a minority market. Its not just me, Toyota has come to the same conclusion and have bet on hydrogen fueled vehicles and does not sell EVs.

 

[woodgeek]

OK. Let's see....

1. Your assertion that a 'large majority of Americans don't believe in anthropogenic climate change' is out of date. The current figure is 65% of americans DO believe in AGW, according to Gallup: http://www.gallup.com/poll/190010/concern-global-warming-eight-year-high.aspx
Folks are buying a lot of trucks and SUVs in the cheap gas era, but a lot of them are smaller crossovers, with CAFE-regulated higher mpg drivetrains replacing older vehicles with poorer mileage.

2. As for it being cheaper to 'drill a hole in the ground and extract fossil fuels' there might be some issues...half the tight oil companies in the US have declared bankruptcy in the last two years and Exxon has had to go into debt (sell bonds) just to cover its precious dividend. Making oil in North America hasn't been cheap for a long time.

3. I have spent more time waiting to fill up at gas stations in the last few years than to charge my EV, and we do about 70% of our family miles on the battery, charged right in our garage. It doesn't 'get old', charging is actually more convenient.

4. The problem with gas taxes is that they DON'T pay for road work....they haven't been indexed to inflation, so road projects have been underfunded for decades. If the state wants to charge me my share (based on average mileage, say 10k miles/yr) when I do my annual registration or safety inspection (with actual mileage) then I'm aok with that. Georgia just started doing that sort of thing, but they set the cost equivalent to about 1000 gallons of gasoline tax per year...like driving a hummer 15,000 miles. Ugh.

5. I won't argue about current utility, 1 car families get plug in hybrids, 2 car families get an ICE and a BEV. Early adopters are kooky early adopters with money in their pockets. Incentives for EVs exist. So what? From an engineering point of view, EVs should be a lot cheaper to make and maintain, once battery costs fall. You can take the bet that they won't get cheaper, if you like, but I will take the other side. My guess is that second generation EVs like the Bolt will sell just fine in NH, when they show up next year.

6. Toyota is the only car maker that DOESN'T plan on making a pure battery EV. Why is a mystery. But they do happily sell the plug-in version of the Prius. ALL the other makers have looked at the market projections, and want to avoid going the way of Kodak. And while several were fielding poorly engineered 'compliance cars' just in California a few years ago, that is ancient history now. The luxury makers are seeing their sales number falling, and see the need to compete with Tesla head to head in the BEV space.

7. Let us know when you test drive an EV and get one.

 

[peakbagger]

Its obvious that you have drank the Kool aid and I wont waste any further time. When I can get a replaceable battery with 400 mile range I will revisit the technology.

 

[woodgeek]

The Kool-aid is sweet. I drink it while I am actually riding in an EV, rather than just reading about them. Its even sweeter that way.

Replaceable batteries were never a realistic technology or plausible business model. Batteries in current use are aok charging at 2C to 80% capacity, so with the right charger, a 30 minute stop is all that's required, assuming no further improvement to the technology. On a car with a 200 mile highway range (Bolt, Tesla, other Gen 2s), that is not a big deal for the occasional roadtrip.

 

[begreen]

Not often discussed is the pleasure of driving a good, quiet electric vehicle. About 85% of our driving is EV. We love it. The Volt gives us a bridge between this option and yet is a great long range driver. For now it provides us with the best of both worlds, but we'll be trying out a Bolt when it comes out.

 

[SolarAndWood]

A fairly key indication that EVs are a niche market in the US is the market for used EVs. Their overall depreciation is noticeably higher than ICE engine vehicles.

That depreciation phenomena exists for the high end hybrids as well and I love exploiting it. The only explanation in my mind of why a Lexus hybrid used is cheaper than a Toyota is image. No self respecting tree hugger (no offense intended) would want to be seen owning a Lexus and anyone that can afford a $75K car probably isn't shopping the used lots for a hybrid.

6. Toyota is the only car maker that DOESN'T plan on making a pure battery EV. Why is a mystery. But they do happily sell the plug-in version of the Prius. ALL the other makers have looked at the market projections, and want to avoid going the way of Kodak.

Not to derail the roof discussion but I love the fact that my hybrid driver and my wood getter both put out 340hp and look forward to seeing what these companies come up with next. Both are incredibly relevant to me and I get why Toyota's strategy is what it is today. I'm all for my next driver putting out 340hp without range restrictions and being fueled by my roof but my guess is that is at least 2 cars out. I think it is much more likely that my 8.1L wood getter that uses 3-4x the gas going down the road will get a hybrid replacement first. It will be interesting to see how it plays out.

 

[begreen]

I think it is much more likely that my 8.1L wood getter that uses 3-4x the gas going down the road will get a hybrid replacement first. It will be interesting to see how it plays out.

Already available, for a price
(broken link removed)

 

[Hasufel]

Sorry for resurrecting an old-ish thread but I just saw some news about the Tesla solar roof: Tesla solar roof prices come in cheaper than some had expected. I'm curious how popular these will be. I might be building in 2019 and I'll be giving these a closer look if they perform well.

 

[EatenByLimestone]

Interesting. Their calculator says a solar roof would cost $47k. I like their warranty though.

 

[peakbagger]

There are a lot of missing details on the shingles. The biggest one is how the wiring is going to be run between individual shingles. That has been a significant issue on past solar shingles concepts. Since they appear to be integrating the Powerwall into the design I expect that the pricing may be getting subsidized by other entities similar to the model that Tesla uses on their cars.

To me the biggest plus is that this looks like a very long life roofing system even if its not solar.

 

[sloeffle]

Interesting. Their calculator says a solar roof would cost $47k. I like their warranty though.

Our roof is roughly 40 squares ( ranch home ). So according to my calculations ( (40*100)*21.85 ) it would cost me $88k to put solar roof tiles on my roof. In our area I can have a good 40 year shingle put on for roughly $500 - $600 a square. Our electric bill is roughly $125 a month. My ROI on my solar roof is 42 years.

I can't afford Elon's cars and I definitely cannot afford his roof. Elon didn't become a multi-billionaire by giving things away.

 

[woodgeek]

Our roof is roughly 40 squares ( ranch home ). So according to my calculations ( (40*100)*21.85 ) it would cost me $88k to put solar roof tiles on my roof. In our area I can have a good 40 year shingle put on for roughly $500 - $600 a square. Our electric bill is roughly $125 a month. My ROI on my solar roof is 42 years.

I can't afford Elon's cars and I definitely cannot afford his roof. Elon didn't become a multi-billionaire by giving things away.

I'm in a similar boat, but would break it out for you.

Tesla makes two kinds of matched tiles, one with PV, and one without PV. The $2k/square assumes that only 1/3 of the tiles contain PV...IOW that you don't put PV on the north side of the roof, an then only 70% of the sun facing side. If you have a BIG roof (ranch) and a small electric bill, your percentage will be much less than 33%, and the cost will be cheaper per square. If you figure 2kW per square with PV in it, 33% in your case would be ~25 kW capacity, and produce 30,000 kWh/yr, likely a good bit more than you need.

How much the real costs would work out, I don't know....but they do have an online calculator......

 

[sloeffle]

How much the real costs would work out, I don't know....but they do have an online calculator......

It looks like Tesla's web site uses Google Solar. Unfortunately Google Solar doesn't cover my house since I am not in a metropolitan area. Below is what I got back from their web site when I put my own numbers in:

$57,100 Value of energy
-$81,200 Cost of roof ---- my estimate wasn't too far off
-$7,000 Cost of Powerwall battery
+$17,200 Tax credit

$13,900 Net cost over 30 years

As you said though, a quarter of my roof would probably cover my yearly electric usage. I'd still be looking at 20k or so to install the solar shingles. Our roof is only a few years old so I think I have some time to think about it.

 

[EatenByLimestone]

Yeah, my payback would take a while too. I use around 170kwh per month.