Consumer Reports Runs The Numbers On Tesla’s Solar Roof

Tesla Model X and Solar Roof

MAY 24 2017 BY MARK KANE 40

Consumer Reports, which six months ago was skeptical about the viability of Tesla’s Solar Roof product, has once again “done the math” using newly announced pricing estimations.

Tesla Solar Roof

Tesla Solar Roof – Available To Order Now, Installed In The US This Summer (Textured Glass shown/available now)

According to CR, it’s not easy to weigh value of the offer, as company’s online calculator “relies upon some important assumptions and predictions that delve deep into the economy of residential solar power in the U.S.”

In its first analysis, CR said that costs need to be below $24.50 per square foot to match costs of conventional roofs (including the cost of Powerwall batteries, but excluding solar incentives or rebates). A 3,000-square-foot Solar Roof would then cost $73,500.

Tesla announced an estimated cost at $21.85 per square foot, which would be $65,550 for the same example house.

After using Tesla calculator for example homes in New York, Texas and California and a 30 years period, CR found out that in some cases Tesla offers a good savings opportunity, although in other cases, it doesn’t look so good.  (Check out CR’s breakdown for those regional examples here)

However, even if one’s first calculations seem tempting, CR advises to answer some questions before placing deposit.

“How will you cover the hefty upfront costs? If you finance the project, obviously it will cost more due to interest. Even with today’s historically low rates, that would add significantly to the cost over 30 years. Alternatively, if you pay the total cost at the time of installation, you’re likely pulling money from savings or investments that could potentially be earning value. “You need to look at that as an investment, relative to other investments,” says Sarkisian.

Also available now – Tesla Solar Roof in Smooth Glass

How long do you plan to own your home? Because Solar Roofs front-load the cost of electricity, the amount you stand to save or lose hinges heavily on how long you stay in your home. A typical owner of a single-family home will stay put for 13 years, according to the National Association of Homebuilders.

Using the example of our staffer’s home in New York, after paying $45,400 for the solar roof and Powerwall, he would save about $16,935 in electricity after 13 years. Even with that savings and $12,500 in federal tax credits, he’d still come out behind by $15,965 if he moved at this point. Some of that loss could be offset by potentially increased resale value, but it’s impossible to predict how much a Solar Roof will add to the value of a house.

How much sun does your house get? Got a lot of tall trees? A tall building next door? That can make a huge difference for the value of any solar array. You can plug in your address at Google’s Project Sunroof to see whether your roof is a good candidate for solar — whether from Tesla or some other manufacturer.

How old is your existing roof? Obviously, it doesn’t make a lot of sense to tear up a new conventional roof to replace it with a Solar Roof. But if it’s not new, you’ll want to factor the age of your current shingles or tiles into your decision, because if you’re going to need a new roof anyway, you may prefer to apply the cost toward a roof that also generates electricity.

Our staffer got two quotes for a traditional asphalt shingle roof with a 30-year warranty, and both came in around $6,800. When you deduct that from the price of a Solar Roof, it increases the savings over 30 years to $20,700 from $13,900.

How effective will these tiles be? It’s important to emphasize that most of these numbers are Tesla’s own estimates and that Consumer Reports has not tested Solar Roof and cannot verify its energy efficiency claims.”

Tesla’s solar calculator can be found here.

Check out the full report at Consumer Reports (via Teslarati)

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40 Comments on "Consumer Reports Runs The Numbers On Tesla’s Solar Roof"

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It is easy to predict how much money is saved over the 30 years, but it is not easy to see how much value that adds to the home? I’d say at the very least the amount of money saved over another 13 years assuming the buyer stays 13 years as well, plus having a roof with lifetime warranty should be worth something.

Another big advantage will be also that it is paired with one or multiple powerwalls and so by design does not have to go offline just because the grid goes offline. When we shopped in 2015 for solar, all the big companies said that wasnt possible in a grid-tied system, that when the power company feed goes down, even in the middle of the day you wont be able to use electricity from your solar system. So we settled for a system with two SMA inverters with an emergency outlet on them to at least be able to power some things in that case after detaching from the grid.

Tesla’s roof has a 30 year warranty, not lifetime, for the important stuff: weatherization and solar output.

And people’s priorities will vary, but for me the prospect of having power when the grid power goes down is of negligible value. I’ve lived in my house for 26 years and have never once lost power long enough to worry about the refrigerated goods. And I don’t even remember the last time I lost it for more than a half hour or so.

Losing power for extended periods of time seems to be on the rise where I live in Northern Virginia. I can’t remember the lights going out for more than 4 or 5 hours from 1983 until 1998. Then we lost power for 2 1/2 days, in 1999 if memory serves. Then the Derecho hit us in 2012 and power was out for 3 days. We have had a few other 12 to 16 hour outages. Even if you keep the fridge door shut, stuff starts to warm a bit in 24 hours or so, and getting a brick of dry ice is a crap shoot.
In this area, having an independent source of electricity is really useful. I have seen the amount of homes sporting a Generac generator boom over the past 5 years. So a PowerWall would fit into the picture pretty well.

The 30 year lifespan (or warranty, anyway) is an important point. There’s a bit of a shell game going on in the sales pitch: they use standing-seam metal and other premium roofs as their comp. OK, but standing-seam has essentially an unlimited lifetime, if I install it my house will supposedly never need another roof. Oh, but the Tesla tiles have an “infinite” warranty and will last just as long (maybe). Well, OK, let’s say that’s true — if the PV output has degraded after 30 years and you want to improve it, you have to tear off those “infinite lifetime” tiles and replace them, because it’s all integrated. On the other hand, the PV system clamped on top of your standing-seam roof? Unclamp, replace, paying only for the new PV, not for a new roof to go with. I still think the Tesla product looks pretty nice but it’s all going to come down to system price. If they undercut standing-seam + PV by enough, it may still be appealing even if the “infinite” lifetime is essentially bogus. But if a tearoff after 30 years is in the cards, it’s a bit hard to see why premium roof +… Read more »

a good real estate appraiser will not have a problem especially as more and more people go solar. In residential you do what is called a paired sales analysis. Find a sale of two homes, one with solar one without. The difference is you value. You can also look at the cost approach but not much weight is given as would be the utility bill savings capitalized over the depreciated period. It’s the net present value of a cash flow stream. This is the kind of stuff they should be teaching us in high school instead of brainwashing our children with their socialistic agenda who are not yet knowledgeable enough to challenge anyone on it.

I would place zero value on a lifetime warranty.

The average lifespan of companies is getting shorter (recent reports state average is now less than 20 yrs and even less for tech based companies).

Given the $$$ put up front, if it won’t pay back in 10-15 yrs, the economics are very risky.


I agree that the long-term viability of Tesla is in question.

The use of average tech company length is a useless metric to show that point. The startup culture in the valley encourages the launch many and fail fast approach which makes the average life meaningless for established companies.

Where I live, the harsh winters and sea coast winds play merry Hobb with asphalt shingles. As well, asphalt shingles are now toxic waste, so extra cost removal and disposal protocols now apply, boosting the cost of replacing after 10-15 years (maximum) A tough 50 year roofing material starts looking better and better as a new build option, especially as it looks great and provides electricity as well.

They aren’t considered toxic waste where I am at. You load em up in a trailer and haul them to the dump. $25.50 a ton.

If Tesla’s calculator really does handle the local utilities pricing policies correctly then that’s a big plus for it. However the payoffs are pretty far out there for me to justify it. even though I tend to stay put for longer than most. …but when one is 68 years old thinking about 30 year payoff times is pretty silly.

If you assume that solar grid electricity costs will decline over time, the roof may not come out so rosy. Tuscon just ordered solar plus storage at 4.5 c/kWh, which is an insane price.

To assume that because the electric company gets their energy cheaper the savings will be passed on to customers is complete nonsense. That never happens especially when they are public. You can count on increasing rates if not due to energy generation cost then due to inflation down the road.

Good correction with facts to a serial anti-tesla troll with nothing but FUD!

Their analysis is flawed regarding “how long you will stay in your home”. This ignores that the solar roof increases the value of the home related to that savings.

The next owner will save money, therefore making the house worth more all things equal. When they move, they will sell the house for more than they would have with a traditional roof. Sure, that value increase is somewhat subjective, not unlike a kitchen remodel:

“…the solar roof increases the value of the home related to that savings.”

Sadly, reports say that’s usually not the case. The next person to buy the house probably won’t be interested in a home solar installation, and someone who’s not interested certainly won’t pay more for the house to get one.

We can hope that this situation will change; that as more and more people adopt solar, it will become factored into the appraised value of the house, regardless of whether any individual buyer wants it or not. But with the current state of things, we can’t assume it will actually add anything.

The latest reports don’t agree with your assessment.

3.5% increase in sales price:

$20k increase in sales price:

$1 reduction in energy bills increases home value $20:

$5900 per kW (though I suspect this has come down since 2013 along with cost of solar install going down):

2011-2013 is not a “latest report”.

I agree with you that it’s like a kitchen remodel. It’s very subjective.

The next owner won’t pay for it. It’s like nav on a used car. It’s nice that it’s there, thanks for paying for it, but I’m not.

Yeah, because a used car gives you money back each month. Read to links posted by Anon…

sure he will pay a higher price for a house with solar cells. He probably can even get a higher mortgage due to lower energy costs.

IMO, solar will become more prevalent, but that will force utilities to change their pricing structure so they still receive enough revenue to cover their operating costs – which are primarily non-variable costs. That means demand charges will increase. Solar may make sense with today’s utility pricing structure, but once the kWh cost drops to nothing and the cost per kW increases to compensate, the benefit of residential solar disappears. Once someone comes out with a way to completely disconnect from the grid, I am in.

Sopfu said: “…force utilities to change their pricing structure so they still receive enough revenue to cover their operating costs – which are primarily non-variable costs. That means demand charges will increase.” That seems unlikely to me. There is a very real reason for demand charges; it’s hard for utilities to balance the second-by-second or minute-by-minute demand from the grid. Suddenly adding an unexpected demand is hard for the utility to deal with, and “fining” those who do so with demand charges is they way they discourage that. But as utilities install grid power backup systems (banks of battery packs, or whatever) — as they are starting to do — they will be better able to deal with short-term demand fluctuations. Such backup systems will allow them to save money, because they won’t so often have an emergency need for more power. With sufficient backup storage, they can also practice peak shaving on a daily basis, saving substantially more money. Now, that’s not to say that this will offset all the lost revenue from customers installing solar power. It may be that the utilities will be forced to raise the basic per-kWh rate — or that regulators will be forced… Read more »

I have none of this stuff, but look at it all the time. Maryland passed a battery-storage tax-credit this Spring (25%, up to $5,000). The battery side of incentives are just crossing state legislatures, and utility commissions. They can’t be in Consumer Reports modeling. Batteries make more sense, as the spread widens between retail KWh rates and where utilities are willing to buy (or net) watts back, not necessarily where watts cost most. This gap is growing. I think Arizona is one of the most abusive, with what were $.10-.13/KWh net metered rates, falling just above $.02/KWh. Nevada, in contrast, looks to be going the opposite way (deregulation/RPS).

There are too many variables in the roof analysis to go with a single approach, and not familiarize yourself with which ones have the most sensitive impact. Beware.

The Tesla roof will be a premium product for rich folks, just like the Model S and X. As it scales price will come down. It’s really that simple. Trying to force it to make financial sense right now is silly. If you’re rich, you want solar, and you don’t want your house to look like a moon base, you’ll want one of these and will pay the premium. (Full disclosure: my house looks like a moon base).

CR is still making the same payback mistake that everybody seems to be making. The Solar Roof is Solar Panels + Roof. Yet people keep doing math on it like it is just solar panels. The math over and over shows that the Solar Roof pays for the solar part of the Solar + Roof quite easily. Then it goes on to pay for the premium Roof part over time. But what is the payback on installing an asphalt roof? Never. Payback on installing a tile roof? Never. Payback on installing a premium metal roof? Never. These never generate any income. If you need to install these roofs new on your house, you only get a portion of what you spend back in increased home value. The rest of the cost is lost as just yet another maintenance expense that everybody has to spend on their homes. Everybody understands this with a non-solar roof, yet oddly forget this when it comes to installing a solar roof. The reality is that the Solar part of the Solar Roof not only generates enough electricity savings to pay back the Solar part of the product, it also eventually pays back the premium Roof… Read more »

The problem with your argument is that for a regular roof+panels the solar output covers the panels quite well too. Much better than this does, since the roof+panels costs less than this does.

Tesla’s claims that it pays back for the premium roof are bunk for the reasons stated many ways above. If you are looking to pay a lot for a nice-looking roof this is a great choice. It does not compete on cost with a roof plus solar panels though. Not even over 30 years or longer.

(⌐■_■) Trollnonymous

I’m not a huge fan of having peeps all over my roof.I prefer having a solar cover back patio.

You have no idea how much of a pain in the ass is to get them install something like that. Most solar companies i talket to did not want to mess with it and the ones that do charged way more to do it. That was my fist choice not the roof but ended up installing on the roof in the end.

I would love a solar car port.

I agree with James above…this is strictly a “wealthy man’s” play and not a “value play”. Heck, every time I look into solar here in North Texas I can never make the economics work. Electricity is fairly cheap here (I pay 5.9 c kwh now and can’t remember the last time I was paying more than about 8.5c). When I look at my roof layout, the cost vs. savings, concerns I’ll move and the fact that no one around here is likely to give you one red cent more for solar (indeed, for traditional systems it might be viewed as “ugly” and unappealing), well…the ROI stinks. On the whole “resale value” thing, solar is likely viewed like swimming pools are – it might make your house more or less desirable to certain buyers, but they rarely given you much more for the house than a home w/o one.

Are those electricity costs based on Generation or do they factor in distribution etc? My entire bill (except for a $4 customer fee – Atlantic City Electric) is a mess of per kWh fees and is split between “first xxx kWh” and remaining kWh are charged cheaper. If I average it out with simple $/kWh it comes out to about $0.185 per kWh.

Yeah, I don’t believe anyone gets changed only 6 cents for kwh averege anywhere in US…at that price solar is not looking great at all.

I would not count on that. I pay 6.8 peak and 5.5 off. Now I do pay a demand charge and a $15 base charge. Strangely – because I manage my demand, have 2 EVs, and had really good incentives, it still paid off for me. Paid about $6k net and save $800 ish a year. Moving about 4 years after installation and $2800 in resale seems pretty easy. No slam dunk but I do live in a rich, white, and reasonably liberal area. Only 1 Prius on the street of 50 and no Volts though. So people might pay 6.5 cents for sure. But then have fixed costs – but solar doesn’t help with fixed costs. Expect more utilities to gravitate to that structure. It actually makes economic business sense. Right now the utility needs about $50 per household in grid maintenance and debt on power plants cost. Then they need about $.05 a kwh for fuel. They can charge a lot per kwh and hope it all works out – and it always does. Or they can charge what matches their cost which will prepare them for larger solar penetration. In other words, they need $100 or so… Read more »

I pay a delivery charge (8.2 cents) and a generation charge (6.9) and both together are at around 15cents. What is your combined rate as it is hard for me to get how much you get charged. Most of us here we mention the combined rate.

I pay about 100$/month for electricity for a 2400sf home here in Calgary, Alberta. I’d take me about 60 years to get even with a solar roof…;) Moreover, the 100$ includes a voluntary mark-up to get 100% of my electricity sourced from wind-farms south of Calgary. There you go, cedar shingles for me:)

Not good for you. I have a $375 avg. monthly electric bill in a 1,789 SF home. We don’t have consistently strong enough wind speeds here in So. Florida for efficient wind power. People have small ones as supplemental. I’ve seen a couple of mid-sized darius’s but they were not spinning very fast. I’m using about 1,800 Kwh. Everything is electric here. During the summer the bill gets up to $425.00 a month.

Hear in Florida We use a lot of concrete roofing tiles, both barrel or s-tile and flat tiles that look like the tesla tile in addition to asphalt shingle. The asphalt shingles don’t hold up that well because of the sun and humidity. Some of our roofs can easily be $30,000 to $40,000 to mid to larger homes and even more. We’ve paying close to $0.12 Kw and we are getting a lot of pushback from the utilities against the alternatives. We’re not allowed to have 3rd party leasebacks where the company just charges you a monthly fee and they cover all the costs.

none or your business

It is shocking that consumer reports does not have an easy print button

Is it mandatory that you have to cover the entire roof with Solar tiles or just a part of it is enough.

All that a home needs is just 3-4 KWh for the household needs. If they want to charge their EV, then its a different thing.

They sell the tiles in two flavors — ones with PV integrated, and ones that are just tiles. Obviously the PV ones will be more expensive. If you click through to their sales page, they have a little slider to adjust the mix. I suppose you could elect to cover just part of your roof with Tesla tiles (whether the active PV or the “just tiles”) but why would you do that instead of buying conventional PV on conventional roof?

As for 3-4 kW (not kWh) being enough for household needs, it depends entirely on the house, the location, and your habits.