Hacker News new | past | comments | ask | show | jobs | submit login
Solar Roof (tesla.com)
690 points by runesoerensen on May 10, 2017 | hide | past | web | favorite | 438 comments

Yikes. I just signed a contract for a new roof here last month, it's going to cost about $12k. Just did the estimate for the Tesla Solar roof... $80,300, so $87k if I want the battery too. I can barely afford the $12 right now, the $80 is just so far over it's not even close, even with how much I save over the years in electricity.

That being said, I love these things, so hoping it gets cheaper in the coming years.

I don't really see the selling point, or value here.

Tesla's calculator estimates $40,500 for a roof that generates half our power needs, and should provide $20,400 worth of energy over 30-years.

Add in a PowerWall and federal tax credit, and I'm still losing $15,400 over 30-years.

If I put that same $40,000 in an index fund that got the stock market's historical 7% average, and waited 30 years, I'd have $308,000.

To put it in another perspective, the last estimates I got for a solar system that covered 100% of our average power needs came in at $32,000 installed, before the same $11K tax credit that Tesla includes in their calculations.

So, I could pay under $20,000 for a "traditional" solar system that covered 100% of our energy bills, or $40,000 for a Tesla solar roof that covered 50% of our energy bills.

That's quite literally half the value, at twice the price.

If I put in a traditional solar system tomorrow, it would pay for itself in year 9. If I put in a Tesla solar roof tomorrow, I'd still be out $15K at year 30.

>If I put that same $40,000 in an index fund that got the stock market's historical 7% average, and waited 30 years, I'd have $308,000.

Are you doing the math all in present dollars? Because the return is 7% after inflation but >10% before. So you'd have >500.000 in 2047 dollars. In this case it's important to do that adjustment because you're doing an investment upfront for payoffs over 30 years so the value of money adjustment is extremely important. It should only make your case stronger though if you haven't done that yet.

The case can be made even stronger if the consumer's efficiency gap is taken into account.

For example from "Market failures and barriers as a basis for clean energy policies by Marilyn A. Brown" we read:

"Meier and Whittier (1983) studied a case in which consumers were given a choice in stores throughout the United States of two refrigerators that were identical in all respects except two: energy efficiency and price. The energy-efficient model (which saved 410 kilowatt hours per year, more than 25% of energy usage) cost $60 more than the standard model. The energy-efficient model was highly cost-effective in almost all locations of the country. In most regions, it provided an annual return on investment of about 50%. In spite of these favorable economics, which were easily observed by the purchaser, more than half of all purchasers chose the inefficient model. The higher purchase price of the efficient model was presumably the principal barrier to its purchase."

An annual ROI of 50% is left on the table because people have to pay something upfront for benefits later!

Tesla's pricing strategy here is quite blunt. They hope people don't care about the costs, only the looks and the sustainability.

Disclaimer: I don't know how sustainable the manufacturing process of this solution is.

I would assume (hopefully) that the following is true: my guess is that Tesla is currently executing a similar plan to produce solar products in the same format they produced the cars - expensive, high end up front. Roll your moderate price, high end products with the income, rinse and repeat.

I think if this is the case, they certainly don't want to hint at it incase they lose consumers who will sit back and wait for the cheaper option they ironically wouldn't arrive.

looks and clique value. never underestimate pretentiousness. you can use this to get people to do good things

If you expect either 7% real returns or 10% nominal returns from the stock markets over the next few decades, you're gonna have a bad time - mostly because real interest rates in the 21st century are much lower than in the second half of the 20th.

Current expert thinking is that there is a 4% equity risk premium over cash interest rates. Current cash rates are 1% nominal or -1% real. If you are an optimist like the Fed, cash rates will rise to 3% over the long term - which gets you to 7% nominal/5% real at best.

I wasn't making a prediction on future returns just commenting on the historical returns used. For this case 5-7% should be more than enough as a comparison to the Tesla investment anyway. I'm curious about those risk premium estimates though. Any pointers or sources on where to read more about them?

Energy prices, and thus savings, are certain to increase over that 30 years too. Quite likely at a rate exceeding inflation.

Energy prices have been mostly flat relative to inflation for 40 years, and there's a reasonably good chance that they will start dropping appreciably (at least during peak daylight hours) as solar continues to make major inroads.

That's true in a lot of places but not really in California, where there's a lot of customers for solar. I don't need to go into the reasons why. It's California.

Why so? California's climate is pretty optimal for solar generation and there's a lot of desert waiting to be covered in solar panels.

Solar is not going to have a similar impact on (say) Ireland in the next 30 years.

More solar will likely result in higher grid energy prices, since people will buy a lot less energy while the grid costs the same to maintain.

Solar can also reduce grid costs, by e.g. shaving the yearly peak power demand, which is usually a summer afternoon so it's not clear cut.

Probably the bigger impact is bad incentives for the people building the grid, who are often able to do what they like and get a guaranteed percentage return on top, which pushes them to spend more than they need to. This has been particularly pronounced in Australia I believe.

Usually when there is additional competition (grid owners generate and supply electricity), markets respond by dropping prices.

This might also be why utility companies have been furiously lobbying against rooftop solar subsidies and Barclays have downgraded US utility bonds.

Solar leases use the 2% inflation rate too as a way to make them look more attractive (as does the solar roof calculator) but in reality electricity hasn't been getting more expensive at that rate.

People made similar pronouncements about gasoline a decade ago. $4/g gas is a distant memory.

Increasing renewable energy sources and an abundance of fossil fuels is going to increase energy prices at a rate higher than inflation? I don't think so.

Not clear on the historic evidence, and especially not clear when you consider people swapping cap ex for op ex.

A 7% yield is an overly optimistic number.

Thats the historical average.

Though the market is expensive now resulting in a lower expected return going forward.

Not really. VTSMX has delivered that over 20 years.

You're not deducting income tax on the dividends.

Or they're putting it in a tax-advantaged account.

> Tesla's calculator estimates $40,500 for a roof that generates half our power needs, and should provide $20,400 worth of energy over 30-years.

This depends quite strongly on where you are. Your numbers are very close to the ones I get if I use my correct address, which is in the Puget Sound area of Washington State.

If I keep everything the same except the address, changing that to one in Merced, California, then it says I'd get $75000 worth of energy over 30 years.

PS: it looks like they try to use the address for more than just finding the location in order to estimate how much sun is available. I tried an address that I had lived at in Pasadena, California, and it did not ask me for the house size and number of floors. Instead, it did the calculation using about 6000 sq ft, which is about the size of the apartment building that is at that address. For my Seattle-area and Merced addresses, it did ask me for the house information.

They are using Google's Project Sunroof[1] to do the modeling. The tool uses satellite images of your roof to create the estimates, and accounts for orientation, shading from trees, etc...

[1] https://www.google.com/get/sunroof

That's amazing. Just seriously amazing.

Funny enough, it was someone's side project at Google.

So was Maps, originally. This is why there's so many fans of the 20% project concept.

Sorry to be a pedant but Maps is not a 20% project, it was an acquisition of a company called Where 2 Technologies. Google Earth was also an acquisition (Keyhole).

GMail however is a 20% project. :)

A distributed file sharing system (later known as the Internet) was Tim Behrners Lee's side project at CERN for a while too :)

He was only allowed to take his 20% project to 100% after his manager wrote up a justification XD

> later known as the Internet

My turn to be pedantic, I guess, but 80 and 443 are only two of many available ports. The internet is much bigger than just the web, even if lots of people never bother to look beyond their browser.

Pedantry is fine by me when accurate and done in the spirit of learning more nuance about a subject :)

An important clarification

If you ever get to go to Geneva, swing by the CERN exhibit. There's the original fileserver, complete with 'This machine is a server. DO NOT POWER DOWN!!' scrawled on tape stuck over the power button. There's also his paper describing the WWW with the feedback of his manager written across the top: "vague but interesting...".

It's kind of comforting to know that my academic and computing experiences thus far are shared both across the globe and across decades.

Haha "vague but interesting".

Isn't it amazing how big of a disconnect there is between "people who are capable of identifying/executing on big ideas" (aka Tim and his manager)....

and "the projects that businesses/agencies want their employees to do"

Especially when, in hindsight, it's anything but vague.

To be pedantic, he wrote "Vague, but exciting". See http://info.cern.ch/Proposal.html for more info.

I'll totally use this when making my next house purchase.

What makes you think that? I'm a little skeptical because Sunroof doesn't cover my address, but I have no problem getting an estimate.

They have a link to sunroof below their estimate. Not sure what happens if you aren't covered by sunroof, but their are a ton of solar estimation tools out there that will give you a rough idea of your potential just based on lat/lon.

Random number generator, I guess. :)

Your electricity is probably a lot cheaper in Washington also and I'm assuming they have local rate information to factor in. Electricity is very expensive in California especially if you use PG&E since they use a tiered rate structure that goes from .12 - .50 cents. And very little of your usage is actually in that 12 cent tier for most people. In states like that I would imagine your solar roof could potentially pay for itself.

Seems off. Seattle gets 1/3rd the sunlight of California.

Isn't the selling point aesthetics? It's very clearly not for everybody, not yet, anyways.

In Colorado it's against the laws for HOAs to ban solar systems, there are some tricks though because they can require certain roofs that you can't really put solar on. Certain tiles and 'presidential' grade roofing which typically cost more than normal shingles as it is. If you live in one of those types of places and want an energy system, then this is what you want. Honestly, I've not heard a lot of complaints about the aesthetics of a conventional solar system, in fact I think some people like it because it's really obvious looking; but if you have the funds and really value the look, then there is an option for you.

It's probably not that different from the market for a Model S vs a Honda Accord. The S is 3+x the cost of the Accord, has fewer fueling stations, can't be serviced nearly as easily, probably is less 'practical' in a handful of other ways but there are still people that buy and drive Model S Tesla cars.

Don't forget the tesla $40,500 includes a roof AND solar. To for a fair comparison you have to include the cost of roof and solar for the next year. Your mentioned other system for $20k that handles 100% of your need doesn't include the roof.

> includes a roof AND solar

...and the cost to remove your current perfectly good roof! I think I smell a bargain!

> Add in a PowerWall and federal tax credit, and I'm still losing $15,400 over 30-years.

Which you probably sink into a second layer of asphalt shingles 15-20 years in (at least up here in upstate NY where there's plenty of rain/snow). Hopefully it's not a tear-off, as that'll cost more.

It's always tearoff. A lay over is saving 2k and shortening the life of brand new roof. Always a bad idea. Unless maybe selling the house soon to a naive buyer.

Wait what, their estimated payback time is 60 YEARS?

This is terrible. They've gotta be just trying to snipe rich early-adopter-for-the-status types.

And whats wrong with that? A bunch of rich early-adopter-for-the-status types will get a Telsa roof, Telsa will get better at developing the technology and the price will come down, meanwhile more people are moving to renewable energy sources to power their homes which is good for the environment. Whats the downside here?

Through the tax credits, we're all paying for someone else's pet project.

Since Tesla's products are expensive, it would be a regressive tax even if we all bought enough solar panels for our needs.

The point of the tax credit is to encourage innovation.

Yes, solar roofs are a bad investment NOW, but they might be a good idea in 20 years, once all these businesses have done this research on them.

If solar roof companies are to get an indirect tax credit then:

1) It should be in exchange for preferred stock/bonds in the company; and/or

2) the tax credit should favour lower prices, not higher

> They've gotta be just trying to snipe rich early-adopter-for-the-status types.

Tesla? The company that brought you the Roadster first, then the Model S and X, and only later the Model 3? I'm shocked. ;)

yeah i know aren't these the exact people that should pay for these kinds of things? I think it's a great model. Can't wait for the model 3 version!

All the rich people that bought the expensive Teslas have used up almost all of the tax credits so the majority of model 3 buyers will be SOL

I'm thinking it's early adopters and new buildings. The Tesla roof on a newly built home may make more sense than a retrofit.

Right, noone is acknowledging SolarCity's pre-existing relationships with homebuilders. http://www.solarcity.com/commercial/homebuilders

It's going to be cheaper (marginally) to build something in at design than after.

In 30 years how many times will you have to redo your roof I think one of Tesla solar roofs points was that many houses in the US have to reshingle. Although I still don't think it might be worth it for you.

Shingle warranties are often 20-30 years.

Not in CO. Lots of hail damage, roofs get replaced on average around 10y mark. Also, insurance, older roof == higher premium.

Lots of houses over 100 years old out there. No reason to think a lot of houses today won't still be standing in 100 years.

roofs != houses

Houses need roofs that last. Why put a new roof on every 15-20 years if you can put one on that lasts the lifetime of the house?

> Houses need roofs that last. Why put a new roof on every 15-20 years if you can put one on that lasts the lifetime of the house?

Please don't seriously suggest Tesla's solar roof will last the lifetime of a house to people.

The real warranty is 30 years for power and weatherization.

Its misleading marketing speak (at best).


> Weatherization means that there will be no water leaks or other weather intrusions during the 30 year warranty period that result from our installation.

It will almost certainly require replacing and/or serious repair long before the "lifetime of the house" is up.

Because unless you go with a metal roof that's a pipe dream.

I live in a house built in the early 1900's with the original slate tile roof still on it and it's in decent shape.

I live in a neighborhood full of slate tile roofs and tile replacement is a fairly routine occurrence. Are you positive that no tiles have been replaced in the past 100+ years?

> put that same $40,000 in an index fund that got the stock market's historical 7% average, and waited 30 years, I'd have $308,000.

stock market isn't a very safe investment (that is, risk is much higher than putting in a bank), you can't make a comparison against buying some equipment, which is zero risk. A closer comparison is putting the $40,000 in a bank that guarentees interest (or treasury bonds, which is also pretty much risk free like a bank) - you'd get $99,457, which is $59,457 over your initial investment.

> you can't make a comparison against buying some equipment, which is zero risk.

Equipment isn't zero risk. It could fail and need replacement, or need dramatic repairs. Or the price of electricity could drop dramatically and your investment won't be saving you as much in electricity bills...

There is always risk. Maybe the price of electricity changes, or the laws change, so you can't recover costs? (Look at what happened in Nevada.)

Maybe Tesla goes out of business or drops support for this product? Maybe they aren't as durable as planned? Also, a roof is part of a house which is a very illiquid investment, and there are a lot of other factors affecting the price of a house.

But, presumably people aren't buying this just as an investment. If you're going to put a lot of money into a house anyway, maybe a fancy roof isn't so bad.

Well investing in solar panels isn't either, 30 years is a lot of time for such (currently not very efficient) technology. Price of the electricity could go down significantly as current renewable or nuclear generators get improved over time, or perhaps someone will finally figure out how to do the fusion efficiently?

I live on top of a hill where we routinely get 50mph+ winds. Explain to me how roofing tiles carry zero risk.

I don't think you understand how index funds work...

Wouldnt increasing the tag price of your home by 15k to absorb the loss when you sell compensate? Also, in 30 years, 15k will be worth less than 15k today.

That only works if it is worth $15k to the buyer.

Plus you have to be in the market to sell in the next few years (plus accounting for depreciation and the like... roofs only last so long).

This new roof has always been pitched as a product competing with new premium roofs. It doesn't sound like that's the kind of roof you're buying.

Every thread about Tesla cars has a subthread about how irrelevant they are because they cost too much for some car buyers. Now we can look forward to every thread about Tesla roofs having a subthread about the initial product not being price-competitive for low-end roof buyers.

You got a $12K quote for tile? How long is the warranty? Remember that the 80K quote includes solar, so you'd have to add a standard solar install of the same KW capacity to your initial quote to really compare apples to apples. You'll probably still pay a premium to go with Tesla, but the no-profile solar integration and lifetime warranty really look attractive. Some people are probably willing to pay for it, similar to people willing to pay a premium for the cars.

No, I just want a new roof. I wasn't planning on installing Solar. Solar was supposed to be a perk of buying the roof from Tesla...and all of this was supposed to cost as much as a roof alone.

Not sure why you got downvoted. But the point is that if you weren't planning on solar in the first place, the long-term economics of a Tesla roof look even better. Your 30-year net cost is $12K + maintenance on the standard roof you got quoted on. Tesla is saying their 30-year net cost is -$50K or -$100K or whatever, to be paid to you in what is essentially credits against your electricity bill.

In either case, you can finance the costs. Given how Solar City usually operates, I imagine they'll roll the costs in a lease or power purchase agreement where you send them a check each month for an amount less than your current electricity bill.

I'm not saying it's the best deal around. You could come away with an even better net total by re-roofing and putting on traditional solar panels. But then you've got an uglier roof, if you care about that sort of thing -- and there are definitely people who do.

Cite? Tesla (at the product launch) actually said it was about as much as buying a new, premium roof + electricity.

Exactly...cost was supposed to be a new premium roof (just the roof, no solar panels) and they are about 3 times more expensive than "just the roof".

Unless they meant a "new roof" as in when you build a house from scratch and you don't have rafters or anything. If you have an existing roof you are redoing every 20 years or so, then this is definitely not the cost of a "new roof".

So, which "new roof" are we talking about here?

> cost was supposed to be a new premium roof (just the roof, no solar panels)

That makes very little sense. You're making an apples to oranges comparison here. It would be absolutely impossible to pull that off. It's literally the premium roof + solar and you want it to be the same price as premium roof (thus, you want the solar hardware to cost nothing.

Only one of these generates electricity, thus saving you money and that must be included in the cost calculation in order to determine the actual cost.

> It would be absolutely impossible to pull that off

And yet it was promised by Musk. Literally "a solar roof will actually cost less than a normal roof before you even take the value of electricity into account".

Don't attack your parent poster for Musk's lies.

Sorry, where'd you get a quote for, say, a "Spanish" tile roof that inexpensive? And yeah, he did say (in the launch video) that the electricity was a part of the computation.

It's not really a lifetime warranty though. If you click through to the Tesla purchasing page, there is (only) a 30 years Power Warranty and Weatherization Warranty... which in my mind renders calling it a lifetime warranty sort of silly, as the purpose of the shingles (power generation) is not covered by the lifetime portion of the warranty. 30 years still seems like a significant warranty for a product like this though.

The odds that Tesla will be around and willing to honor their warranty 25 years from now are also nowhere near 100%. Also, if you read the fine print, you will notice that the warranty will not cover the most frequent cause of roof problems - leaks in the seams.

The same can be said for your local fly-by-night roofer, but it sounds like you can buy two roofs for the price of a SolarRoof.

Also, another thing to be concerned about is whether or not you're going to be stuck in the middle of a pass-the-blame around football match between Tesla, and their subcontractors. (I guarantee you that the people installing your roof will not be Tesla employees.) In roofs, installation mistakes can cost you dearly - they are the primary cause of roof problems.

You can insure against roof damage too, it is a pretty standard part of house insurance.

You can readily buy a 30 year shingle roof. Calling it a lifetime warranty when it is no better than a common, good quality shingle roof is absurd. Metal roofs have even longer warranties.

50 year asphalt roofs are all over.

It's totally fair to just balk at the price.

Someone that doesn't install solar can sell the home without worrying about recovering that cost.

Considering how long Tesla has been in existence and how financially leveraged Tesla is I would take discount warranty value (lifetime of house or infinity whatever comes first).

Can't project finances much more than 10 years max. At the moment cost of capital is low but that may well change in that time-frame. Things have to make sense in a decade or so also considering that this new technology that is obsoleted by incremental innovation.

It's definitely the lifetime of Tesla and not your house, roof, or owner.

Yeah there's a pretty legitimate possibility of Tesla/SolarCity collapsing if their stock had a long bad run, don't think your warranty is worth much at the back of the line in bankruptcy court.

12k for asphalt shingles, or slate / terracotta / etc? They're going to be targetting people who are looking for slate or terracotta aka more expensive than asphalt shingles like most of us have. Prices likely will come down with more volume. We can hope at least!

I am not sure there are a lot of folks who will spend 70k on a roof. Even if it reduces or eliminates their electricity costs.

For this to succeed it is going to have to cost the home owner at least what a shingled roof would cost with the additional cost of the power-wall and the infrastructure that is required to to set that up. I can understand paying a slight premium but 70k?

You would be better off using a high performance insulation like spray foam, 3 pane windows, and even installing a Geo Thermal System (around 20-25k) instead of this solar roof.

Where I live $80k is a significant portion of the cost of most houses. The price will be a significant barrier to entry for houses outside of hot real estate markets.

Yeah, my brother just bought a pretty large house for $100k, but I guess people in rural North Carolina aren't the target buyer of solar roofs anyway.

I wonder on what price home would a $80k roof make sense? >$800k?

That sounds about right to me.

A roof that exceeds 10% of the purchase price is likely to push the house outside of the price range of buyers in the target market.

I know a friend of mine (who has a solar system, not quite the same) but basically got almost nothing for it. The aesthetics of a "Solar Roof" is better but I don't see it raising the value of the house by more than 10%.

I used their calculator using the estimates when I had my roof done last time, and it is just not economically feasible.

$60k roof vs. $6k roof.

Net of $12k savings over 30 years.

$60k over 30 years (adjusting for inflation in conservative investments) is easily going to hit $180k.

I have a $2M house, and I've been bitching and moaning for a year that a new roof cost us $20k.

I dunno, I'm in the Dallas/Ft Worth area, and we have abundant sunshine and I think the price is still going to be a barrier.

But like others have said... there are plenty with a lot more money than I have which will jump at this. I'm ok with that. The more wealthy folks that install these and take their load off the grid, the better.

It depends on your roof orientation and your location so ROI has a huge range.

For example if you don't have a southern facing roof then this is going to be a terrible investment. However, this is also a home improvement which means a low interest loan which has many tax advantages, remember you pay your electric bill with after tax money but you pay interest on a home loan with pre tax money. Further electricity costs increase with inflation, so your out of pocket investment may be tiny while the value of electricity generated is increasing.

South facing roofs aren't essential to solar. East-West layouts can spread the energy production out through the day and work out better overall depending on various factors such as how much you make from selling excess to the grid.

These are tiles that sit flush with your roof, east west roofs act like zero tilt panels which provide less power everywhere in the US and thus lower efficiency. Granted if it's cheap enough that's not a deal breaker, but it's always going to impact ROI.

Yeah, I balked at first, but it looks like mine (~1400 sqft 2 story house), would cost $30k, and there's a lifetime warranty on the roof. I might consider it in the long term future, but would definitely want to give it a few years and see how things pan out first. This is one of those things that I wouldn't want to be an early adopter for.

Did you take into account the 30% federal tax credit on that 30k?

EDIT: That's sort of the kicker. A regular roof does not get a 30% federal tax credit (plus possible state incentives), nor does it produce power for 30+ years, nor does it have a lifetime warranty. If you can obtain low cost financing, you almost always come out ahead.

> EDIT: That's sort of the kicker. A regular roof does not get a 30% federal tax credit (plus possible state incentives), nor does it produce power for 30+ years, nor does it have a lifetime warranty. If you can obtain low cost financing, you almost always come out ahead.

Maximizing retirement savings is still likely more cost effective than this roof for most people and I doubt many people in the US are putting away $24k/year.

The only way I'd see this is as viable is below inflation interest and people showing they can sell the houses for the full value of the Tesla roof.

> Did you take into account the 30% federal tax credit on that 30k?

If I understand the tax credit correctly, it's only available if you're paying that much in taxes otherwise. For a $60k roof, you have to already be paying $18k in taxes to take full advantage of the credit. That's an important detail for some.

The tax credit can be carried forward multiple years until your tax liability has exhausted the credit balance.

There is a button on the calculator to change your settings.

It sized my roof at more than 2x the square footage of my house.

It also estimated my monthly electric bill at 4x what I pay on a monthly basis.

Changing those numbers put them to something closer to a new roof; and is definitely competitive with putting on a new roof and then paying for a solar panel installation.

The $80k roof is especially scary if you live in an area with any type of natural disaster risk.

The area I live in just had a huge hail storm. Most roofs in our neighborhood will require repairs. That's a bummer with asphalt shingles, but it would be a lot worse with an $80k roof.

Most people won't think about those risks, but over the time period you need to consider for a roof, it's a big risk in most places.

Elon posted a huge hail cannonball hitting a roof tile: https://www.instagram.com/p/BT7HVS3AZ4q/. It looks pretty resilient.

Tesla claims their shingles are a lot more resilient than standard roofing material...

They say the glass is warrantied for the lifetime of the house, but it will be interesting to see what exclusions are in that warranty.

According to the ordering website where it says "30 years", I'd say the exclusion of t > 30 is rather extensive...

How on earth did you hit 80k? Using the calculator, the roof for a two-story 3000sqft home comes down to $50-60k, with a net gain of $5k. If your house is any larger than that, $80k is pocket change.

> Using the calculator, the roof for a two-story 3000sqft home comes down to $50-60k, with a net gain of $5k. If your house is any larger than that $80k is pocket change.

That's hardly pocket change in most of the country, where you can get a lot more sqft/$ (and potentially in a bigger, 1-story footprint) than on the west coast.

> two-story

Not everyone has a two story house. My parents live in a single story 2k square foot home and tesla estimates the cost to be $69k. I live in a 2 story house with more groundfloor space than 2nd story, and it estimates the cost at $60k

I own a two-story, 3000 sq.ft. house, budgeted to the usual percentage of total income. I assure you that $80k is not pocket change (because I didn't pay the down payment with pocket change, and even that wasn't $80k).

Doesn't the Tesla roof last substantially longer? Like maybe 2-3 times as long as asphalt ?

From the description:

        Solar Roof is the most durable roof available 
        and the glass itself will come with a warranty 
        for the lifetime of your house, or infinity,
        whichever comes first.

> Solar Roof is the most durable roof available and the glass itself will come with a warranty for the lifetime of your house, or infinity, whichever comes first....

... Or 30 years. You know, whichever comes first.

Also typicallt the whole roof wouldn't have solarpanels. Only the side in the sun. And the dummy shingles will presumably be alot cheaper.

~$42 versus ~$11 per square foot (solar vs dummy tiles) per the Ars article. So depending on the amount of solar coverage you want, can get, need, you can manipulate the price a bit.

Take into account the fact that Model 3 + battery pack + roof will cost 80k-100k in 10 years. In France electricity cost almost double and fuel is 50% more expensive.

It's all flash and no substance. Elon Musk is a great salesman and marketer. I'll give him that. But just like their cars, this roof is for the wealthy people who want to look cool and earn some liberal points. It makes no financial sense for the vast majority of people.

> That being said, I love these things, so hoping it gets cheaper in the coming years.

Yep. Perhaps in the future.

> But just like their cars, this roof is for the wealthy people who want to look cool and earn some liberal points.

What does political affiliation have to do with this? People being excited about new and innovative technologies like electric cars, space travel, and solar roofs is great news for people reading a site like Hacker News - I don't think it would be out of line to suggest most new technology is marketed towards those with the disposable income to purchase it.

There is no need to make this into a "stupid liberals just trying to score points" issue.

> What does political affiliation have to do with this?

Well liberals love to pretend they are environmentally "conscious" while conservatives are "drill baby drill"? Right? Maybe I should have written fake california liberals.

> People being excited about new and innovative technologies like electric cars, space travel, and solar roofs is great news for people reading a site like Hacker News

I love innovative stuff. Solar roof isn't innovative.

> There is no need to make this into a "stupid liberals just trying to score points" issue.

I wasn't trying to score points. I was just being honest and offering my opinion. I'm fairly liberal myself...

Huh, I don't know much about roof costs, but which bar was incorrect in their price chart for you: the asphalt or the solar tiles?

From their chart, the solar tiles (installed) should only be about twice as much as asphalt.

That's a very misleading chart.

(1) The solar tiles aren't actually on the chart. If they were, they'd have to extend the scale more than twice as wide as what's shown, out to past $40 per square foot based on their calculator.

(2) The bar that is on the chart is for their "non-solar" tiles, plain glass squares. That's the one that's twice as long as the bar for asphalt tiles.

The solar glass tiles are actually more like 10x the cost of asphalt shingles, including installation.

While doing the calculations I read "Cost of Powerball ticket" instead of "Cost of Powerwall battery"... laughed loud as it would be useful to help pay it off.

Not sure why all the negative energy.

They are going after the portion of the market that would replace their roof with a high end material, and are interested in solar.

If you are a home owner in this situation, you could consider investing into your home. The roof will pay dividends over the next 30 years, and is attractive and durable.

I think it will do extremely well. Perhaps the best opportunity is in new construction. Imagine having 50k more baked into your mortgage, but having your roof lower your ongoing energy costs! Great potential in that market, could also optimize the roof designs for power generation.

yeah there is little economic incentive for anyone outside of California will to retrofit these onto an existing house. Take Texas for example a large house in Dallas is $500k I used the provided calculator on the Tesla site and the roof install will cost $211k! that is not justifiable on a house this expensive.

Right. Outside of dense, expensive cities, the %of house value goes up since houses cost less AND the roof sizes also go up.

Is that to replace 100% of the energy usage with solar? It lets you dial back the electricity generation and with it, the cost.

> negative energy


I have always been a huge fan of a quick transition to sustainable energy sources. There is just one little thing I don't understand.

Why they expect people to make electricity at their homes? You can buy a little piece of land in a dessert, put solar panels there and distribute the electricity to other places. And you don't have to climb on any roof during the installation or the maintenance.

It is not profitable today in a free market to bake your own bread or to plant your own vegetables. Because if it is done in a large scale by professionals, it can be made much cheaper while keeping the good quality. So I don't understand, how the home-made electricity could economically compete with the professional energy farms of the future.

Not an expert here but a couple things come to mind.

From an environmental perspective, it is better to use surface area which is already built up than pristine natural desert land. The house itself already imposes an ecological cost. A solar roof adds around zero to that cost.

I've heard the stat thrown about that 50% of energy generated is lost to transmission. If that's true then there's efficiency to generation at home.

It probably doesn't figure into anyone's decision but decentralized generation leads to a more resilient "grid". As it stands we are potentially vulnerable to warfare/terrorism attacks on the grid.

Tesla the consumer brand is about being smarter than your neighbor. Wow you have a car which is electric yet more performant than my car? Wow you have solar panels and the aesthetic is better than mine? Wow you're completely off the grid? So much material for dinner parties. In short there is a good value of cool factor for amount of work. And there are people who break the market logic and bake their own bread, plant their own vegetables.

You're right that power from a solar farm will be an option somebody but for many people it's not an option yet. This is something you can do in the near term.

> I've heard the stat thrown about that 50% of energy generated is lost to transmission. If that's true then there's efficiency to generation at home.

It's more like 5%. The larger numbers you're thinking of might be including generation losses. Coal plants are around 33% efficient in terms of converting the fuel's energy into electricity. Natural gas is better, but still under 50%.



Decentralized solar generation helps the grid in some ways but hurts it in others, specifically the need for sundown peak generation. See for example the "duck curve" problem that CAISO is facing: https://www.caiso.com/Documents/FlexibleResourcesHelpRenewab...

Only if you don't have batteries at home. Tesla promotes buying the roof with a battery pack which would allow you to use evening energy by battery and charge overnight (good for the grid) for the morning peak.

It's the right question to ask.

Home electricity costs around $0.15/kWh, while power plants sell electricity to the grid for around $0.03/kWh. The difference pays for installing and maintaining the grid and local distribution wires to your home. Depending where you are (I live in a forest, where a tree falls on the power lines a few times a year and they have to send out guys in a bucket truck to fix it) it's expensive.

Because of net metering, home solar panels effectively get paid the home rate. It's kind of unfair. If you have enough solar panels to zero out your home bill, you're getting something valuable (reliable nighttime power) that cost money (to install and maintain the wires) for nothing. But that's the system we have.

Sometime before we hit 100% solar power, the system will have to change.

My electric costs are 0.035 USD/kWh here in Europe (Czech Republic).

Wth is wrong with the USA? It seems like you're getting screwed over everything. 10x electricity, 100x healthcare and education - is US market really just a bunch of colluding monopolies?

I couldn't quite believe your numbers, and couldn't find any confirmation for them: http://ec.europa.eu/eurostat/statistics-explained/images/4/4...


Hm, that seems unusually high, really wonder where these stats come from. Is every eurostat statistic distorted like that?

Here's a chart of energy prices on a Prague energy exchange, currently it's about 30 EUR/MWh = 0.032 USD/kWh. I pay a bit more than that (incl. distribution) with a good tarif (low cost broker), but even conservative people I know who don't renegotiate energy prices get about 0.06 USD/kWh incl. all distribution fees.

That said, electric distribution network in our country is probably underinvested. Is the premium you're paying in US based on distribution network cost?


Still seems low for retail. In Europe, the UK has very low costs with ~12-13€c/kwh, high cost countries such as Germany are more around 25-30c/kwh (taxes and renewable energy charge).

Electric rates in the US vary widely. The $0.15/kWh rate sounds like California prices, which are notoriously high compared to other parts. Less urbanized states have lower rates, except Alaska and Hawaii.


There's a really great 99% Invisible episode (podcast) going over all the economics & history of net metering for those interested!


Speak for yourself. My home electricity costs right around $0.30/kWh. If you can't get a net metering contract, it's already about cost-effective to just go off-grid.

The economic calculation for one of these roofs probably looks very different depending on where you live.

Not necessarily - my home was built in 2013, with a metal roof and 5kW PV system. But because it's so efficient, I end up not just zeroing out my bill, but giving power to the grid for free (since I don't actually get paid for the power I generate, I just get credits). I have evened the odds out now to some degree with a plug-in hybrid, but I will have to see if in practice charging it will soak up some or all of the surplus I was losing...

If you live uphill from work, then that car just might help to balance the load. Early in the morning, you leave with a minimal charge, and roll down to work on regenerative brakes while topping up the batteries. After work, you spend that charge and the minimum fuel necessary to get home. You charge your vehicle in the late afternoon, not long after peak sun. Your home power controller is configured to allocate 80% of the car's battery for household usage, overnight.

If you live downhill from work, however, then the only way to use that to your advantage would be to work an evening / night shift.

When home solar installations send excess power to the grid, they also do it in the middle of the day, when wholesale electricity prices are at their highest.

For now. When 10% of people have panels, that won't be true anymore.

So cheaper prices at the time of most usage (and previously highest cost to generate or consume) which is yet another positive externality of solar power.

You build a solar farm out in the desert it is up to you to maintain it and the supporting infrastructure (transmission lines).

Put a solar roof on a home and it is the homeowner's responsibility to maintain it.

There's also the values of geographic distribution:

* on site transmission cost is $0 for power used

* the effect of a man-made or natural disaster in one location is contained: throwing a breaker for maintenance at the Arizona border doesn't shutdown power across an entire region: https://en.wikipedia.org/wiki/2011_Southwest_blackout.

Many states have generous subsidies that only apply to residential/domestic energy production that don't apply to utility/commercial production, specifically there are credits and rebates for the construction cost, and the feed-in tariff system - these really shift the economics completely.

I live in western WA and I had a view to get a solar installation a couple of years ago, because despite our climate and sunshine conditions - and already having the greenest (hydroelectric and wind, mostly) and cheapest electricity in the country ($0.11/kWh) - there was a generous feed-in tariff - which meant my planned $40,000 investment in a solar system would pay itself off after 10-15 years, however in late 2015 the state decided to put an end to that and if I had the system built now it would take 25+ years to pay for itself, at which point the system's warranty would be expiring and I'd need to shell out more money to replace it.

It's because local photovoltaics can save a lot of infrastructure and can require nearly no labor.

You don't buy cold air piped from across the city, you make it locally. Why?

You don't buy cold air piped from across the city, you make it locally. Why?

In Sweden it is quite common to pipe hot air (and to a lesser extent cold air) across the city rather than each house making it locally. Once of have the basic infrastructure in place it is a lot cheaper and more efficient.

> It's because local photovoltaics can save a lot of infrastructure and can require nearly no labor.

No, they don't. You still need almost the entire national power grid to supply your home with night-time electricity... That infrastructure won't be going anywhere.

An even worse outcome will be every home having local power storage infrastructure. Tens, or hundreds of thousands of dollars for a power wall, or a compressed air storage system is much more expensive then maintaining the grid.

Since we are discussing Tesla solar roofs, they suggest your installation comes with a PowerWall, thereby storing power during the day to use at night. I personally don't think we are there yet, but I think the goal is that you don't need the entire national power grid just for night electricity, just a big battery.

Batteries + roof PV, is far more expensive on a per-watt basis, then a power grid + utility-scale generation.

"Just buy a $15,000 PowerWall, which you will need to replace every 10 years" is, compared to grid electricity, incredibly wasteful.

There's a reason why customers and users overwhelmingly prefer centralization, even if its harmful for them in the long-term. It's cheaper, and people would prefer it to be someone elses' problem.

Have you done the math? If net metering didn't exist, my back-of-the-envelope calculations say it would probably break even in California. With net metering, sure, it's pointless.

My parents pay $1,200/year for electricity, in a fairly large house. Given the expected lifetime of a power wall, that will eat all the 'savings' of living off the grid.

There's also the matter that if, say, 40% of the population disconnects itself from the grid, that doesn't mean that the cost of maintaining that infrastructure will drop by 60%. Someone will have to pay for it.

Where are you getting $15,000 for the powerwall? It's $5,500 for 13.5kWh, which should be enough for nighttime loads in many houses (but may require some inconveniences, like not running the dryer at night).

You are right that it does not yet work out, it's $0.17/kWh for the powerwall (assuming you fully charge/discharge it each night) + cost for panels. Given that grid-disconnected users would want some buffer, an off-grid system probably works out to ~$0.40/kWh all in for battery-stored electricity

You could save a big chunk of this by some habit changes, most of the cost comes from the batteries, so scheduling energy intensive activities to run during the day reduces your cost for them to $0.10/kWh or so.

Honestly I am surprised how close these numbers are. I initially was sure the grid would survive in cities, but now I am not so sure. In 10 years these numbers will likely be half what they are now (batteries in particular will be way cheaper). It might all be enough to kill the grid in many places.

In many places in the country, night-time usage is a lot less than daytime usage.

Cold air cannot be transported over long distances. Electricity can.

Both can, with losses and infrastructure investment. The size of those are very different, and that's why you does currently create one locally and buy the other from far.

Photovoltaics can¹ change the other side of the equation² so that locally generating it would be better.

1 - But it's not certain by any means. The current biggest obstacle is battery storage and maintenance.

2 - losses and infrastructure costs vs. gains from scale.

Well there's a bunch of factors. Energy distribution is not free or perfectly efficient. You are also doubling the footprint of the house+solar and land (nor it's ecological impact) are free.

Additional solar power absorbs sunlight and produces electricity. One benefit is that the house under it is cooler and needs less air conditioning as a result.

Also balancing the energy infrastructure for a state/country with significant solar/wind sources adds significant new complexity for the power grid. It's definitely most efficient to keep your homes power use off the grid as much as possible.

Additionally at least in California peak power use is air conditioning related and follows a power use curve pretty similar to solar production. So the hottest days/times have the most power generation (there's some lag). This allows the state to minimize power production only for those worst case days in late summer, which is the most expensive (power, cost, and environmental impact) power plant.

Power plants can be quite efficient if utilized 100%, but the difference between minimum power and maximum power needs can create huge inefficiencies where solar can help.

I'd also argue that adding distributed power use makes the grid overall much more robust. Earthquakes, major storms, attacks against infrastructure, etc are all less of an issue if a decent fraction of houses produce most of the power you need.

Land is expensive? A desert solar farm's value is what the panels built on it can produce. The value of your home property is that you can live on it. Adding solar panels just increases the value of property you already own (assuming you're in a sunny enough location, etc. etc.).

My guess would be this: there are large transmission costs associated with utility scale solar, perhaps home generation can be competitive when including those.

A local power company in my town does this (New Zealand) You buy a 'solar panel' and they add it to their solar farm while giving you the equivalent discount. The best thing is that if you move house the discount follows you.

That's a much better option than what my utilities provider offers. I can pay extra, and they will purchase wind energy for me (or at least claim they will). It is a lot more compelling to purchase something tangible, even if the end effect is theoretically the same.

Both approaches make sense. Large utility solar installations are a great way to generate electricity, but there are transmission losses to consider and there just aren't enough large scale solar projects yet to supply all the power that's consumed.

Rooftop solar gives you a way to be less dependent on the local utility for something you need to live a modern lifestyle. If you live somewhere where electric rates are high or power outages are common or most of the electricity comes from burning coal, you can now work around that by generating electricity locally.

It's sort of like storing a file locally versus storing it "in the cloud". Both approaches will probably work, but you might choose one or the other based on some weighted combination of reliability concerns, privacy concerns, available bandwidth, and whether you want to share the file across multiple computers or multiple users.

> it can be made much cheaper while keeping the good quality

I'll spare you the anecdata, but the choice of bread and vegetables are specifically poor support structures on which to build your argument for centralization. They can (in some cases) be made more cheaply, but the quality suffers substantially.

Electricity, while lacking the strongly subjective "quality" dimensions of food, still suffers from long-range distribution. Transmission and stepping losses (as well as transit costs) are a large portion of why we don't have just one enormous generation center for the world. There's obviously a balance, but for the cost of land and the added loss of converting solar's DC to AC, local generation gets a little more advantage.

One reason I don't see mentioned here is the element of risk. Establishing a solar farm is an expensive operation, and likely carries a lot of risk - particularly as a first mover. Contrast that with a potential ROI for home owners.

If you stay in a hot area, you're also going to save money from lower AC bills, because the solar panels would absorb some of the heat that would otherwise enter your house.

A lot of the cost and inefficiency of electricity is the storage and transmission over long distances.

Decentralization of energy generation is a very nice thing to have.

Tesla acquired SolarCity in November in a deal worth $2.1 billion.

At the event, Musk said Tesla's roof would price competitively with normal roofs and could even cost less.

"It's looking quite promising that a solar roof will actually cost less than a normal roof before you even take the value of electricity into account," Musk said at the event. "So the basic proposition would be: Would you like a roof that looks better than a normal roof, lasts twice as long, costs less, and, by the way, generates electricity? It's like, why would you get anything else?"

I think he was specifically referring to slate and/or clay roofs, not asphalt shingle roofs.

Like most similar comparisons, it's essentially "our cheapest X will be the same as the most expensive of Y."

From all the comments I've read, it really sounds like it's going to make more sense outside of the US. Here in the UK the vast majority of roofs are either clay tiles or slates which are expected to last 50 or more years, but the US seems to largely fit cheaper asphalt shingles and replace them more often.

At the moment our slate roof is fine, but when it needs replacing I'll certainly look into the Tesla tiles. Hopefully we'll be able to hold off for long enough that they will have come down in price. I'm sceptical that they will be worth it, but if they make sense then we would definitely think about it.

But that does not make more sense. If they last 50 years, but your solar roof only has a 30 year warranty then you might look at a complete solar roof replacement, while your average roof would still be good another 20-30 years.

As a Canadian, our common perception of the UK is that it's always cloudy and rainy. If that's true, would it make sense to put solar tiles on a home if the ROI is negative or would take a few hundred years?

Most of these things require high production amounts which allow refinement and bulk orders.

The first Tesla Roadster's ended up being around $110K.

They're now doing Model 3's for $35K.

I expect the same with the roofs -- they will drop price drastically, but they need to get them out there first.

>They're now doing Model 3's for $35K.

What do you mean it isn't the point? They haven't even started production on the Model 3, let alone delivered one for $35k, which is very unlikely to happen. So it's yet to be seen what they'll deliver for 35k. And by the way, the second model(turned out to be the X) was also supposed to be cheaper than the first (Model S). It wasn't. Musk is already announcing the 4th model will be cheaper than the 3.

Meanwhile you can buy a Chevy Bolt today with 238 mile range, MSRP $37k before tax credits, ~$30k after.

The more upscale BMW i3 with 195 mile range can also be bought today, at ~$35k after tax credits.

If GM can build enough Bolts to keep up with demand (the waiting list here in Europe is apparently 12 months now), and with the other big players trying to catch up (Hyundai, Nissan, Ford all expected to have 200+ mile range models in 2018), Tesla has to hurry up and deliver on their target price, delivery dates and volume.

It's not the point. The point is they are doing something drastically cheaper than it was, because of mass production.

Even if it comes out to be 40K or 45K -- that's still way lower than it was when it started.

You can get nitpicky about the specifics, it's also completely expected that Musk is always late but always delivers, and usually for a little bit more than expected. This is his MO.

They haven't delivered a Model 3 yet.

That's not the point. Sales from their previous, more expensive models allowed them to ramp up production capacity for the Model 3.

Sure it's the point. If they don't actually hit a $35,000 price then it is a bit much to credit them for bringing the price down to $35,000.

35K is also the base MSRP which almost never happens in a car sale.

Not even close. Enormous borrowing and investment raising allowed them to ramp up production capacity.

strange how they didnt do that right out of the gate... maybe nobody would lend and invest in a company with no history of building a car, let alone one that was deemed impossible? now lets put on our after the fact analysis hat, where cause and effect are blurred and previous uncertainties are already resolved and we can conclude whatever what we set out to conclude. and thats how we get from "this car cant be built" to "i could have done it".

> At the event, Musk said Tesla's roof would price competitively with normal roofs and could even cost less.

I think we may need to start applying a "multiplier" to any costs or delivery dates that Elon mentions. I love him to death but he does have quite a history of underestimating these things.

At the roof launch event, Elon was very clear that it priced competitively with high-end roofs. And that appears to be what the actual price competes with.

He may have also been implicitly including an offset for the energy cost. A bit disingenuous, but they've done that before.

I'm 21, thus I have no idea what roofs normally cost. I assume they're very very heavily below ~80k? For a "regular" house, what would a roof cost? 4k? 10k? 500?

I can give a quote on the sort of roof materials this competes with.

I had to have the tile roof on my 1923 house replaced due to a massive hail storm (in roughly 2006). The house's footprint is about 1000 square feet, so not entirely sure of the actual roof area (probably about 1200 sq/ft), but the bill for removal of the old roof, some repairs to the sheathing, and replacement with new tiles was about $55,000 - materials (Ludowici tiles) and labor.

The solar roof quote for our roof from the Telsa website was about $48,000. So, in my case it would have been competitive.

My new tile roof has a 75 year warranty, btw.

My roof is 1600 sq ft. It had a metal roof on it, which is considered more expensive than asphalt. It was 40 years old, which is the how long metal roofs are expected to last. I replaced it myself for around $2000. Most of the cost was $1600 for the metal roof. Then there was $400 in special nails and trim parts and sealer. It would have cost a little more if it wasn't metal before since I'd have to have added the spacers. Metal and asphalt replacement are sort of DIY possible, but asphalt is dirty heavy work. Metal is less dirty and dangerous, just remember to wear leather gloves. Also probably don't attempt if one's roof has more than a couple gables etc. It's better if you've done it before in any case. To have someone else replace the roof would have cost at least twice as much. Could be three times as much in some parts of the country.

If I were to have switched to slate or terra cotta or glass solar tiles I'd have to tear down the roof and rebuild it because normal houses in the US are not designed to hold that sort of weight, it requires a stronger roof structure, and sometimes stronger walls to hold the heavier roof. Possibly the rest of the structure would have to be reinforced as well. Doing this correctly requires a consultation with a licensed structural engineer. That sort of roof rebuild would cost from $20,000 - $50,000 depending on the scope needed according to the engineer, and that's before adding the roofing materials.

+1 for adding in the cost to support the extra weight.

Many homes, even ones they're building now, are not designed to support anything more than a few layers of standard asphalt shingles.

BTW, it's ridiculous that we're talking "down" to asphalt shingles now because of this. Some of those come with 50+-year warranties now...

It varies pretty widely based on the material - asphalt shingles are the cheapest of the cheap, and that's what most people would be comparing this to. Tile/slate are much more expensive.

Tesla's initial product is actually intended to compete against premium roofs, not low-end. There are lots of places where you're not even allowed to install a low-end roof due to homeowner association rules.

We just got an estimate for our house (~2400 sq ft single story home) and the estimates were from 10k - 13k.

Add in the various types of metal roofs and the price can double for a similar sized house.

I had my (very boxy and boring) 1800 sq ft house reroofed with 30 year asphalt shingles for ~$7k, including tearing off both previous layers of shingles.

I looked at getting a metal roof, and standing seam was going to cost about $16k.

Edited to add: The cost of living is cheap where I am.

>I looked at getting a metal roof, and standing seam was going to cost about $16k.

Same. There seems to be a subset of HackerNews who thinks that most homeowners can pay $50k for a roof and $35k for a car. It's cool high-end stuff, but certainly is not mainstream.

$35k for a car is absolutely mainstream - in fact that's just about the average price for one...


That's the average for a new car. Most people don't buy new cars.

True, but from the car manufacturer's point of view, all of their customers buy new cars, so comparing what is low-range or high-range to other new cars makes sense.

The used-car market in the US shifts three times as many cars as the new-car market.

For a new car. Lots of people buy used.

A 2000 sq ft tile roof would cost about $20k in a large city. The same roof with asphalt shingles would cost about $8000. The warranty difference from 10 to 30 years, the slope and shape of the roof, and local disposal and labor differences will all affect the price.

In modeling whether this makes sense, I looked at my annual electricity bill, which comes in at about $1,800/year. That's not enough savings opportunity to justify a ~$70,000 roof+batteries.

However, when I add 2 electric cars, the savings nearly triple [0]. Instead of buying gasoline, I'll be paying for electricity.

At $5,400/year, spending $70,000 starts to make some sense.

On the other hand, if I put up ugly panels and still use the Tesla batteries, aren't I going to save a lot more?

[0] 24,000 miles/year, 225 miles @ $10 per charge, vs. 25 mpg @$3/gal

EDIT: Corrected KWh charge... $10 is cost for one charge.

What's your goal though? If it's just to save money then it makes more sense to drive a beater gasoline car.

If the goal is to help the environment, it's probably still better to buy a beater gas car and buy carbon credits with the difference. Also there are tons of other things you can do like downsizing, eating less meat, biking to work, etc.

Tesla's entire offering is trickle-down environmentalism.

In your calculation, $10/kWh is a bit high... the national average is $0.12/kWh

Corrected (thanks for being kind...)

Keep in mind, a battery array isn't something patented by Tesla, you could easily (safety in mind!) create a "powerwall" yourself; or use someone else's.

I think Elon got ripped off on his last shingle roof. The bar chart is nice but off by at least 150%. I've had many roofing subcontractors as clients past and present in Northern California. Based on an average of 870 roofs in 2016 for Single Family Residential homes in the bay area, Asphalt shingle roofs are $3.12 per square foot for materials and labor. The highest was $5.75 psf and the lowest $2.35 psf. Note that the SF bay area is considered one of the most expensive in roofing market. Also note that Solar City has a poor reputation in the industry for hard selling larger than needed residential solar systems.

The roof launch event was very clear that this is a product that competes against premium roofs. Asphalt shingle roofs aren't premium roofs. As an example, for high-end housing developments, many of them do not allow asphalt shingle roofs.

If that's not your thing, great. Then this isn't the product for you.

The article specifically cites a source talking about asphalt shingle roofs: "The price was calculated for a roof where 35 percent of the tiles are solar (solar tiles cost more per square foot than non-solar tiles), in order to generate $53,500 worth of electricity, which according to Consumer Reports would make a solar roof more affordable than an asphalt shingle roof."

Yet they'll allow those shitty* cedar roofs that look like crap in 20 years...

*Shitty in how they look, not how they perform.

I can drive through a 600k+ neighborhood (5x-6x higher than the average house in my metro) and see this terrible looking shingle. I honestly feel bad for Mr. Jones who can't afford a new cedar (or fake cedar) roof because the option of a nice asphalt isn't allowed in his HOA.


For a counterweight let me present this interview[0] with the CEO of "the largest privately held solar contracting company in America", near the end of which he says several disparaging things about Tesla's roof, including,

> When I saw the demo he did at Universal Studios... What I saw was a piece of glass that looked like it had a cell in it. The challenges he’s going to have is, how are you going to wire it? Every one of those shingles has to be wired.

> Roofs have valleys and they have hips and they have pipes. … How are you going to work around that? How are you going to cut that glass? Are you going to cut right through the cell?

The latter question is perhaps answered by the posted article, "Solar Roof uses two types of tiles—solar and non-solar." So Petersen's question is moot, the glass/solar tiles don't have to be cut to fit in a hip or around a flue, that will be done to the non-solar tiles that look the same.

The question of wiring is open: imagine the grid of wires that have to underly that roof, and getting them all put down without a break or a short, by big guys with nail guns (if you've ever watched roofers at work -- it isn't a precision operation).

Then Petersen goes on to say,

> So I would say for the record ... it’ll be cost-prohibitive. ... For $55,000 I can give you a brand-new roof that will last forever — 50 years — and I can give you all the solar you can handle. ... (Musk’s) product is going to be north of $100,000.

The graph in the posted article does not directly address total up-front installed cost, but rather tries to combine cost with some anticipated lifetime energy return -- a procedure with a LOT of variables and assumptions. I would like to see real numbers for a Tesla roof, $/sq.yd installed.

[0] http://www.mercurynews.com/2017/05/04/from-summer-job-to-sol...

You can use their calculator to edit any of the assumptions, and the math is fairly transparent.

The question of installation is a straightforward challenge that's easily testable, presumably they have a solution that works or they wouldn't announce yet. It's pretty obvious to see if it's going to work or not: just send a team out to put on a test roof and see how much work it is.

[0] https://www.tesla.com/solarroof

OK I just put my address into the calculator and I think the thing's bogus. Without asking anything about my house size or my solar exposure, based solely on my address, it gives me a hard figure ($53,100) for the roof cost and a 30-year energy income of $76,100.

I call bullshit. First, I do not believe they actually know the size of my house or the orientation of the (numerous) roof pitches to the sun. Spoiler: it's only 1300 sq feet and the longest roof ridge is oriented NW-SE, far from optimal for exposure.

Then there are the three very large oak trees that shadow it from three sides.

Then there is the fact that my utility is a local one, not PG&E, and I doubt they took the different rate structure into account. And if they did, how the F do they know what Palo Alto utilities will charging in 10, 20 or 30 years?

They don't know. The whole calculator is a bogus fantasy toy.

That's actually exactly the data they're getting from Google's project Sunroof. I'm not sure how correct that data is, but I haven't seen many complaints.

I'm so absolutely excited for solar power. Tesla's Solar Roof, their PowerWall batteries, electric cars. It's all just painting such a bright future. Certainly Tesla has no monopoly on it, but they've made it sexy and are pushing the bleeding edge forward. Props to them.

We recently signed a contract to do an installation on our house (with a local contractor, not SolarCity). It can't happen soon enough! We'll have enough panels and batteries to be 100% off-grid throughout the entire year, plus get a good chunk of change back from the Net Metering every year. Pay off is only 8 years!

That installation is enough to cover our normal electric usage. Longer term I want to replace our gas appliances with electric and replace the car with a Tesla. Then we can double our solar installation to keep pace and BAM we will be 100% clean energy and off-grid. All while saving a bucket of money.

The thought of running off grid in the middle of a Southern California suburb? People might think me crazy, but guess what? At least we're doing our small part to save the planet, and saving money doing it. So who's the crazy one?

Going off grid means you need a lot more batteries, which need materials and energy to make.

Switching from gas to electricity for heating is a bad idea if there's still coal power stations in use, if you're not selling your excess power to the grid, they're going to turn on that coal power plant again.

Sharing power is a much better idea than trying to store it in batteries, unless those batteries are in a car

> Switching from gas to electricity for heating is a bad idea if there's still coal power stations in use

You misunderstand. Our solar installation will be expanded to cover the appliances. We'll be 100% off-grid.

> Going off grid means you need a lot more batteries

We only need 3 PowerWalls to cover all our needs (~1 for our needs now, 3 for when we have electric appliances and a car). That's not "a lot more".

> Sharing power is a much better idea than trying to store it in batteries, unless those batteries are in a car

Huh? Why would sharing power be a better idea? Solar panels generate the majority of their power in ~4 hour window. Energy storage is _mandatory_.

Sharing power via net metering is better (for the environment) because there's no conversion loss from charging a battery.

Perhaps I'm not understanding the argument. My interpretation is that y'all want me to dump all my excess power during the day into the grid, to power other homes that don't have panels, instead of charging a battery. And that's somehow better for environment.

But ... when night falls, and I'm not generating any more power, where am I supposed to get power? Do I just live without power every night? And everyone else does too? Cause the only alternative is to burn fossil fuels to power everyone's homes during the night. Fossil fuels being perhaps the most inefficient solar batteries available to us.

And yes, fossil fuels _are_ batteries. Solar batteries in fact. It's just that they have an unimaginably terrible conversion loss, not to mention they're highly destructive to the environment, and take millions of years to charge. If they ever do recharge, which is unlikely, since our planet is not likely to revisit the eras that gave rise to significant quantities of them again.

I think I'll stick with lithium cells with their "conversion loss" of 80%, that take up a small portion of a wall in my house, and last for decades.

My points are: 1. To go completely off grid, compared to 80% off, takes many more batteries, and is therefore inefficient.

2. Using those batteries a lot every night wears them out more.

3. There are many alternatives to fossil fuels at night, wind, tidal, solar salt heating, nuclear, biofuels. Whether it's better to share or store would depend on many factors.

a) What power sources are used on your grid b) What the demand is at each point in the day c) The transmission efficiency vs the battery conversion efficiency d) The resource cost of the batteries

Until the power companies start devaluing your power because there's a surplus of solar on your street and they don't need it.

There are still a lot of places where the cost/efficiency of natural gas makes more sense.

Water heaters, stoves/ranges, etc.

>All while saving a bucket of money

I'd double check my math, because economic law says that's unlikely.

We're paying ~$19.5k for solar panels + installation. After the tax credit, that's $13,650 in cost. We spend ~$960/yr on electricity right now. The solar installation will cover all those needs, plus pay us $711/yr. So we're saving $1,671/yr. Pay off is thus ~8 years. The panels are good for 25 years. That's $28k in savings by the time the warranty runs out. They'll probably last longer.

The batteries are a different matter. I believe net meter makes them irrelevant, so the equation stays the same for most "sane" people. For me, I want to be off-grid, so I'm happy to pay a premium for batteries. That said, SGIP makes them roughly free if we get lucky. We'll see what happens.

That's much cheaper, than this article. Where is this?


I understand where these people who are saying it sucks and it's too expensive are coming from. It is more expensive than normal solar panels.

BUT! How many wealthy people have beautiful houses that don't have solar panels? Why do you think that is?

Tesla has this cool factor that didn't exist for environmentally friendly things before. How many super rich people drove electric cars or hybrids before? Now Teslas are one of the cool things to have.

They are absolutely targeting a different segment of the population, but I think overall it's a very positive thing and it'll probably work.

I'm super excited about all of the great stuff happening in solar recently, but whenever I read about the economics of home solar, I'm also always reminded of how stacked the deck is for wealthy people vs. poor folks. There's a very large federal tax credit for solar investment. That's great...but, people who can't afford their own home get no such credit, and there's no way for them to get such a credit. That's a super common trait for lot of incentives; they go to people who need them least. And, the people who are getting these incentives, are also using a lot more power (bigger houses, more power), and so even with solar, their huge houses may still be contributing more to emissions than the poor folks who aren't getting any tax breaks living in apartments or rental properties.

I don't really have any answers on this, I just think it doesn't get talked about enough.

Maybe it would help to think of the credit as benefiting the solar industry more than wealthy people. It's a long road for new tech to reach economies of scale. If society has an interest in reaching that inflection point than the subsidy could be money well spent. Poor people will benefit when the price of the roof falls further; it may never have reached that point without early subsidy.

Perhaps it would be more equitable if Tesla received the subsidy directly. But that places the government in the business of choosing winners without the market signals of who would actually succeed if given the subsidy. Politically that's such a minefield. And no one ever lost votes for promoting a tax cut.

How about a tax credit for lower power consumption, instead of subsidizing any one path for achieving it?

This is tautological; the reason poor people don't get a lot of tax breaks is because they don't pay a lot of taxes. The government does spend a lot of money helping poor people, but not via tax credits.

It's not a tautology because tax credits aren't the only possibility for providing incentives.

Imagine you worked for $10/hour, and somehow got put in charge of designing the incentives. Do you think they would look like this? I don't.

The tautology is in only looking at the subset of spending that's done through incentives, and then complaining that it disproportionately goes to people buying expensive stuff. That's what incentive means in this context: incentive to buy expensive stuff.

Anyway, you're coming at this all wrong. If I was in charge of designing this program, my mandate would not be to help poor people or rich people, it would be to increase solar power. How do you increase solar power? By paying for part of it. Who benefits? Whoever's buying it. Who pays to install solar power? Not poor people.

Or here's another way to look at it: What's the whole point of having a solar power incentive? To get more solar power. Now suppose we changed the law governing solar power incentives to exclude rich people (or tall people, or right-handed people, or any group of people). What would happen? Less solar power.

That might be a desirable outcome, if you are more opposed to rich people getting tax breaks than you are to fossil fuels. But in that case, why not just raise taxes on rich people, and leave the solar incentive out of this?

I'm speaking of incentivizing reducing power usage in the general case, not merely tax credits. The current solution is "let's give wealthy people more money to play with" (to questionable benefit to the general welfare). I should be clear I'm not saying I oppose tax credits for reducing usage; I'm just saying that poor people aren't getting the same kinds of benefits for using less power, even though they are using less power than the wealthy folks getting kickbacks.

And, again, I don't have ideal answers. But, I think there's a problem with the government consistently serving wealthy folks, even when those folks are living in much larger houses and consuming far more resources. Should a person with a 4000 sq ft house, consuming 5x the power of a lower income family in an 800 sq ft apartment, really be getting paid off to reduce their consumption?

If we're serious about the problem of climate change, energy independence, etc., we have to start looking at the actual numbers. If five low-income families are consuming the same resources as one wealthy family...what needs to change to bring the 5x family's consumption down? Solar incentives are one of the options; but, again, they serve only the wealthy (and, as far as I know, most solar installations do not replace the entire household usage, and only reduce it by 30-50%). That outsized power consumer is costing everyone more in terms of what it will cost to respond to climate change.

The question is why are the wealthy being rewarded when they're still consuming more than their poorer neighbors (well, probably not actually neighbors...the poor folks are on the other side of town due to zoning laws).

And, on another "class war" theme, the poorest people are the ones being hit hardest and soonest by the effects of climate change. The multiple "100 year record-setting flood" events in Austin destroyed poor southeastern neighborhoods twice in the past five years. Those were the lowest cost neighborhoods, and decisions were made by the Army Corps of Engineers to protect more expensive homes, and ignore the risks to the poorer neighborhoods. Lousiana, Florida, the Carolinas, have all had major weather events in the past several years (not all can be proven to be the result of climate change, but the severity and frequency seems clearly on an upward trend) and the impact has been predominantly borne by the poor.

OK...I went off on a bit of tear there. My point is that I feel a certain discomfort at how readily environmental causes are used to strengthen the position of those who are already wealthy and already relatively safe from environmental destruction, while the folks most likely to be impacted are invisible.

I applaud you for trying to think through this stuff, but minus all the ranting it sounds like what you're basically saying is that there are a bunch of ways we could be (but aren't) spending government money to reduce energy use while also helping poor people. How confident are you of this? Can you name a couple? For example, are you aware that most states already offer subsidies for buying more efficient appliances, and for installing attic and wall insulation, and for sealing heating ducts? (no citation, but I used to work at a non-profit that administers such programs) Characterizing the current policy as "let's give wealthy people more money to play with" is inaccurate, unless you think the people filling out the form to get a $50 rebate on attic insulation are doing so on a yacht.

I readily admit I am not a policy wonk (though I follow environmental issues more closely than most).

I am aware of green home initiatives at various levels of government (I've owned a home in the past, and have taken advantage of some of those). Again, I'm not opposed to the subsidies and tax credits that incentivize power reduction.

> Characterizing the current policy as "let's give wealthy people more money to play with" is inaccurate, unless you think the people filling out the form to get a $50 rebate on attic insulation are doing so on a yacht.

We're not talking about a $50 rebate. This is a tax credit worth several thousand dollars, for an upgrade that increases the value of a home by a notable amount, for a home that will probably still consume more power than a poor family's apartment.

My concerns about this are:

1. We are past the point of inevitable crisis in terms of climate change; we really can't do enough at this point to stave off significant human health, ecological, and economic impact. Even if we, as a nation, started making significant changes today (which we are politically farther away from than we've been in decades), we'd still face serious problems.

2. There are households that consume multiples of what poor families consume...and they're being rewarded with heavily discounted amazing new home upgrades because of it, increasing their wealth and decreasing tax revenue. Yes, it has a positive environmental result, and it may be worth it, but are there ways we can reward lower power users, too. Many municipalities have tiered power prices; e.g. .11/kWh for the first 500, .12/kWh for the next 1000, etc. Maybe that needs to be more aggressive. Directly addressing usage can incentivize a wide variety of changes, and discourage McMansions (which are disastrous from a wide variety of angles). Egregious energy consumers are externalizing their environmental impact. (This is even more true on a commercial and industrial level but that's another discussion entirely.)

3. Poor folks often can't get any of the stuff you're talking about (e.g. subsidies for insulation), because they rent. So, they are at the mercy of their landlord for how efficient their home is (and that's a potential problem with tiered pricing; there obviously needs to be incentives for landlords to increase efficiency and disincentives for owning inefficient properties, too).

I think you're taking my talking about the issues as being Policy Pronouncements, and that those pronouncements can be simplified into "Take money from rich people and give it to poor people".

It isn't (and I tried to make that clear in each of my rants on the subject). I am not saying, "These subsidies should not exist, and we should give money to the poor." I am saying, "Poor people are getting fucked daily, often to improve the position of wealthy people and in the name of something inarguably good, like 'protecting the environment'; how about we start trying to figure out how to fix that?" Add up the thousands of tiny ways wealth inequality is enabled in the US, often in the name of good things (like making neighborhoods safer, improving the environment, reducing drug use, etc.), and we end up with the low churn of wealth, and increasing chasm between the classes, that we currently see.

I get where you're coming from, I just don't think it's very relevant to solar power or energy subsidies. The rich were getting richer and the poor were getting screwed a long time before solar power was invented; I don't see how these subsidies are any better or worse an example than anything else. It feels like your issue is more emotional than anything else (hence why you keep saying "rewarded", as if homeowners buying solar panels weren't spending their own money on something that benefits their community). As in, it feels distasteful to spend money on something that benefits the rich, when you're hyper-aware of the plight of the poor. That's understandable, but it's a terrible way to think about a policy like this, because we spend about $4B/year on solar subsidies, which is enough to make a noticeable difference in solar installations but nowhere near big enough to affect income inequality.

Believe me, I'm all in favor of "Take money from rich people and give it to poor people". Which we already do, in a variety of ways! I just think we ought to be able to talk about specific policies like "Should we spend money on getting more solar power?" separately from that. You think climate change is an urgent problem? I agree, which is why the objection you're raising here seems like quibbling. If an asteroid were hurtling towards the Earth, and someone proposed that we build a rocket to fly a ragtag group of oilrig workers led by Bruce Willis to blow it up and save the world, would you stand up in that meeting and say, "Yeah, I guess that would work, but I'm concerned that it might exacerbate income inequality"?

Registration is open for Startup School 2019. Classes start July 22nd.

Guidelines | FAQ | Support | API | Security | Lists | Bookmarklet | Legal | Apply to YC | Contact