Tesla Solar Roofs Are Very Expensive And Their Warranty Is Far From Infinite

In October last year, Tesla announced they were making tiles with built-in solar cells that would allow a roof to generate electricity without the need for solar panels.  Installations of these solar roofs will start in the United States in June and you can go to Tesla’s Australian site and slap down a $1,310 deposit to reserve one.  Tesla says they will be available here in 2018 and, given their record of meeting their own self-imposed deadlines, they should definitely arrive before the heat death of the universe.  Just so long as they don’t get cancelled like the DC Powerwall 2.

Tesla’s solar tiles generate electricity like solar panels but are indistinguishable from normal tiles, so it will look as though your roof isn’t doing a damn thing about global warming.  I don’t really see how that’s an advantage, but I’m sure it will appeal to people such as Coalition politicians (but not Malcolm), coal company CEOs, and those who simply think their roof would look better without solar panels.

Because Tesla over hyped the original Powerwall, has delayed installations of the Powerwall 2 and cancelled the DC version, and hugely exaggerated the the return a Powerwall 2 can give, they have developed quite a reputation for bullshit.  Connoisseurs of the finest bovine fecal material will be pleased to hear the tradition continues with their solar tiles.

Tesla’s CEO, Elon Musk, said he expected a Tesla solar roof to cost around the same or less than a regular roof.  Its actual cost is 4 times as much as a regular Australian tile roof and 2 to 3 times as much if the regular roof has a conventional rooftop solar system of similar capacity.

Elon Musk also said the solar tiles will have an “infinity” warranty for the life of the house or forever, but this only applies to the glass that the individual tiles are made from and not their ability to produce electricity or function as a roof.  Their actual warranty when it comes to providing power or preventing a down pour from becoming an in pour is 30 years.  A 30 year warranty for resisting weather is not exceptional.  In Australia Monier has provided a 50 year warranty for their tile roofs since 1997.

Americans build roofs very differently from Australians and their tiles are quite different from ours, but the Australian Tesla site makes no mention of how they’ll be installed in this country.  There is also no mention if they meet Australian standards, either as tiles¹ or as a solar system².  We also still have no information on how the solar tiles will be wired up or what kind of inverters they use.  We don’t even know if inverters are included in the price.

I would say I’m disappointed, but higher than promised prices and inadequate information is exactly what I’ve learned to expect from Tesla.  It’s fine to have dreams and aspirations that you can’t quite meet.  That’s not the problem.  It’s important to aim for the stars, even if you sometimes fall short and hit London.

But when you start taking people’s money you are no longer working in the field of dreams.  Any company that takes deposits without providing clear details on what the customer is buying, a firm delivery date, an estimate of the cost in this country, and whether it is permitted to actually be installed here, sets off my shoddy business practices alarm.  Tesla has me wondering if their habit of asking for deposits long before they can deliver is a sales tool to find people who are bad with money.

Elon Quotes On Cost

Elon Musk, Tesla’s CEO, said:

“The apples-to-apples comparison compared to a regular roof will be at least at, and we believe slightly below the cost of a regular roof, and the electricity is just a bonus.”

And he also said:

“Would you like a roof that looks better than a normal roof, last twice as long, cost less and by the way generates electricity?”

Elon Musk is clearly a very sloppy guy.  When he brings the reusable stages of his space rockets back to earth and lands them on a floating platform in the ocean, they can afford to be off by a good 3 or 4 meters in any direction and still be fine.  But then he goes and brings the same sloppiness into solar roof pricing and instead of coming in at the same or cheaper than normal roofs as promised, they are 4 times more expensive.

This is not rocket science, Elon!

Tesla Provides US Prices With Their Online Calculator

Tesla gives no information on how much their solar roof will cost in Australia.  But on their US site they have an online calculator I used to find the cost there.

I wanted to use a sunny American site to give the Tesla roof a fair chance and after a little research I said:

“Tesla, you can shove your solar tiles in Uranus.  Specifically, Uranus Terrace, San Francisco.”

I chose San Francisco because solar output there is almost identical to Brisbane and I chose Uranus Terrace because uranus is ancient Greek for “sky” and so it seemed an appropriate site for a solar roof, while also having the added benefit of sounding like “your anus”.

The online calculator then wanted me to enter “home square footage”³.  I decided to make the home reasonably large and entered 200 square meters (2,153 square feet) with a single floor⁴.

The calculator then spat out the solar roof would cost $69,700 US.  Using today’s exchange rate of 75 Australian cents to the US dollar, adding 10% GST, and then subtracting $6,338 as an estimate for the value of STCs⁵ gave a price of $95,889 Australian.  That’s about the cost of a Tesla S electric sports car.  There are towns in Australia where you can buy a house for that much.

Tesla Roofs Will Have Solar And Non-Solar Tiles

The calculator said the total area of the roof would be 245 square meters.  The extra 45 meters is added to account for the tilt of the roof and the eaves.  This is more than I expected, but I assume it is typical for American roofs.  Solar tiles would cover 50% of this area while the rest would be identical looking non-solar tiles.  This means 122.5 square meters would be devoted to producing solar electricity.  If solar panels with 18% efficiency were used this would be a huge 22 kilowatt solar system.  But because solar tiles are far less efficient than normal solar panels its real capacity will be much less.

An Estimate Of The Solar Roof’s PV Capacity

Tesla could have easily told us the efficiency of their solar tiles, but they didn’t.  However, it is possible to work it out as their calculator said the Uranus solar roof would generate $99,900 US in energy savings over 30 years and by looking up the San Francisco residential electricity price they based that on and after accounting for the 2% inflation Tesla included in the result, it is possible to estimate it produces around 13,000 kilowatt-hours a year which is roughly the output of a 9 kilowatt solar system.

Tesla Solar Tile Efficiency Is Low

A 9 kilowatt array that takes up 122.5 square meters has a very low efficiency of 7.3%.  But if 50% of a roof is solar tiles, then a lot of those tiles aren’t going to be facing in the best direction.  Allowing for this means Tesla solar tiles are around 8% efficient.  This is less than half the efficiency of the average new solar panel installed in Australia.  A rooftop system with 9 kilowatts of 18% efficient panels will only take up 50 square meters.  So if you want to generate as much electricity as possible from a limited amount of roof space you do not want to use Tesla solar tiles.

Cost Of Tesla Solar Roof Versus Normal Tile And Solar

At around $96,000 Australian the Tesla solar roof is not cheap.  Metal roofs here are around $85 a square meter while a typical tile roof is about $100 per square meter laid⁶.  Using the online calculator’s figure of 245 square meters of total roof space, a normal tile roof would cost around $24,500.  That’s one-fourth the cost of the Tesla roof.

A 9 kilowatt rooftop solar system with good quality components might cost $12,000.  So a new tile roof plus a rooftop solar system with the same output as the Tesla solar roof would come to $36,500.  That’s much less than half the cost of the Tesla Solar Roof.

Changing the size of the roof in the online calculator makes little difference to the comparison.

The Cost Of Capital Makes Things Worse

The Tesla roof in Uranus costs around $60,000 more than a normal roof plus a conventional rooftop solar system.  If that extra money is borrowed then interest will have to be paid on it.  If it isn’t borrowed then it represents money that can’t be invested elsewhere to make more money.  This makes the economics of the Tesla solar roof even worse than they already seem.

The Tesla Roof Warranty Is Not Infinite

You may have heard Tesla solar roofs have an infinite warranty.  If you thought that sounded too good to be true it indicates your anti-con artist defenses are strong, because it is too good to be true.  While the glass tiles themselves have a warranty for the lifetime of the house, which technically could be forever⁷, their performance warranty for providing electricity is for 30 years and their warranty for actually functioning as a roof and not letting rain and possums pour through the ceiling is 30 years.  While that isn’t bad, it’s not impressive.  Monier has been offering 50 years warranty for tile roofs since last century.  They also install solar tiles but they’re not indistinguishable from normal tiles like Tesla’s.

Tesla Solar Tiles Aren’t Made For Australian Roofs

American tiles are not the same as Australian ones and if you look at photos or videos of American roofs under construction you’ll see they do things very differently.  In Australia, while there may be a reflective aluminium foil layer under the tiles, usually there is nothing.  But in America they build a roof underneath the roof.  It’s like their roofs have underpants while ours go commando.

In order to get Tesla’s American style tiles to stay on, an Australian roof may need a lot of work done on it.  This may significantly increase the cost in this country.  The Australian Tesla site is happy to take your money, but makes no mention of this.

We Know Very Little About Tesla Solar Tiles

Tesla says the performance warranty of their solar tiles is 30 years, but they don’t tell us what performance that actually covers.  We also don’t know if they have a separate product warranty.  We don’t know how the tiles are wired together or what sort of inverters are used.  We don’t even know if the cost of inverters is included in the price of the solar roof.  We don’t know what kind of maintenance may be required or how much that may cost.  And we don’t even know if they can be installed in Australia.

Either Tesla knows these things and has decided not to supply this basic information to the people they are taking money from or they don’t know the answers and so are nowhere near ready to be taking people’s money.

Either possibility is bad.

Tesla Solar Roofs Will Often Be Completely Unnecessary

Because Tesla solar roofs are so incredibly expensive the only reason to buy one is if you really like the look of a roof without solar panels.  And you’d have to not just like it, you’d have to love it.  With Tesla solar tiles in Uranus you’d have to love it with $60,000 dollars worth of passion.  But the expense may be completely unnecessary because normal rooftop solar often isn’t visible.

In the United States plenty of places get significant snow.  As a result their roofs are steeper than ours so it slides off.  This makes their roofs more visible than ours.  But in Australia people often can’t see your roof or can’t see large parts of it.

I paid to put to put a solar system on my parent’s roof and despite spending plenty of time there I’ve never actually seen it.  For all I know there are no panels and the installers simply spliced into the neighbor’s power line and put in a timer so it only steals electricity during the day.

This means a conventional solar system can often be installed while leaving the roof with exactly the same appearance it had before.  Even if the only place normal solar panels can be placed without being seen is facing south, where they will only produce around 75% of north facing panels, it would still be far cheaper than to pay for a Tesla solar roof.

So before you slap your deposit money down, please first check if installing a normal rooftop solar system will make any visual difference to your home at all.

Tesla Solar Tiles Are Not For The Environmentally Minded

If you like saving money then Tesla tiles aren’t for you and if you are concerned about appearances they will often be unnecessary.  But if your main focus is on protecting the environment then Tesla tiles definitely aren’t for you.

One of the best things households can do to protect the environment is install as large a rooftop solar system as they reasonably can.  The much higher efficiency of normal solar panels means you will be able to produce far more electricity from a limited amount of roof space with them than Tesla solar tiles.  But an even more important environmental consideration is the expense.

For the cost of a Tesla solar roof you could pay for a brand new normal roof and roughly 6 times as much solar capacity as the Tesla roof provides.  While this is unlikely to all fit on your own roof, the money saved could be used to put solar on roofs of relatives or charities.  The money saved could also be used to invest in energy efficiency.  You could even buy an electric car, charge it with solar power from conventional panels, and reduce your environmental impact that way.  (I’ve heard there is an American company that makes some good ones.)

A Commentary On Vanity

I want you to think of a close friend of yours.  In your mind’s eye I want you to picture his or her face, hear the sound or his or her laugh, and visualize his or her mustache.  I want you to think about the good times you’ve had together, the evil times, and the neutral times.  Now after doing all that, I want you to ask yourself, have you at any point ever given a damn about what their roof looks like?  Do you even know what it looks like?  Because unless you have a habit of flinging pizzas on it there is a good chance you have never given it a thought.

Now I want you to imagine a complete stranger.  Like my brother.  No one is more completely strange than him.  Do you give a damn what his roof looks like?  The answer to that is probably no.

Because we evolved under conditions where survival depended upon whether or not Fred was thinking of clubbing us or Wilma was thinking of cooking us to feed Pebbles, we have a strong predisposition to worry a lot about what other people think, even on matters that are inconsequential, such as what our roof looks like.

But when you actually collect evidence, such as asking people if they care what your roof looks like, you’ll soon start to see that no one gives much of a damn.

Sure, if you did install a Tesla solar roof your friends would probably tell you it looks great, but that’s because they don’t want you to think badly of them.  The chances of them actually caring about your roof are close to zero.

If you want to buy a Tesla solar roof because you like the way it looks, please go right ahead.  But don’t make the mistake of thinking anyone else really cares what your roof looks like.  Because they don’t.  Not in Australia.

If you don’t believe me, then check out what our Prime Minister’s roof looks like:

Note this is not the home of a typical, low rent, Prime Minister who is only paid as much as the President of the United States.  This is the home of a genuine multi-millionaire.  In fact, his millions are so multi he was able to contribute a couple of them towards becoming Prime Minister.

If a humble Australian multi-millionaire can reach the highest office in the land with tiles that look like that, then clearly no one here gives a pint of bat piss what your roof looks like.