"Traditional shingles set a very very low bar."
And yet they can work pretty well....
owner builder here, my house was shingled 30 years ago. They are in good shape for that age, but I need a new roof in the next five years.
I built the house with the correct slope for max solar gain (8 in 12 pitch, interesting to work on!). Still deciding between a roof installation and a ground array (26 acres, not many trees, so I have my choice of locations -- also no money, so not something happening immediately). I looked at the solar roof when it was announced, and again yesterday. Still no technical details on the website.
Meanwhile, I've been refreshing my memory on the measurements. I have a very basic roof: about 36' x 22' facing south, and the same facing north. (there is also a two car garage, but I'll ignore that for now). So 8 square (100 sq ft) south, 8 square north. 1600 square foot of roofing materials total. I was looking at what I thought were good quality shingles, about $110 per square. Shingles equal $1760. As a DIY job, probably $2000 total (nails, etc)
Alternately, I could go with a metal roof. No estimates on that yet. I suspect very similar price.
For a roof sloped like mine, I figure a 30 year life expectancy for shingles is a fair figure. Maybe even 40 if I buy ultra premium shingles. At any rate, past my life expectancy. So the replacement in 2050 is not my problem.
I'm waiting to get the rest of the story on the Tesla solar roof. But if Elon is right and I can get one for $2000, it is a strong candidate. (my suspicion is that it is more of a taxpayer $$ to Musk move, aren't solar panels unlimited in the 30% tax write-off you can get? So instead of $6000 for 5000 watts of panels, you pay $15,000 for 5000 watts of shingles and then the government gives you 3X the money back?)
PS - I ran the numbers for a north facing roof thru PVWatts, there seems to be about a 40% hit for having solar facing north. I don't know how that plays out, Tesla shingles that are cheaper without the solar, just so the roof matches? Or solar shingles so cheap that you don't even care.