The solar roof is expensive, and probably only makes sense if a new roof is being installed - and even then it's likely going to take 20+ years to achieve break even.
For an existing roof, solar panels will likely cost less, though could take 10-20 years to break even, depending upon the cost of local electricity.
When evaluating break even, another factor to consider is the benefit of having backup power available with PowerWalls. If you're in an area with frequent power outages (California) or susceptible to hurricanes (Gulf/Atlantic coasts), the solar/PW combination could support extended off-grid operations, without relying on a noisy gas generator.
When projecting long-term cost/benefit, another factor to consider is the likely future increases in electricity costs. When our utility company indicated we could see a 30% increase in our electricity rates this year, that helped to justify going solar. Even though we were able to find a less expensive plan to renew for this year, the long term trend is clear - the cost of electricity is rising due to the shift to relatively more expensive renewable energy sources coupled with the increased grid costs (likely to expand the grid to reach the new renewable energy fields).
The solar roofs are somewhat like buying a Tesla S/3/X - there is a higher upfront cost, which is balanced out by lower longer term costs (maintenance, fuel cost savings).
If we were building a new house now, we'd strongly consider incorporating solar roof into the plans - along with other energy saving features (foam insulation, LED lighting, energy efficient pool pumps, ...).
You've quoted verbatim the mantra of the people that are selling the solarglass roof with power walls. But the math doesn't support ANY of it.
I do need a new roof due to hail damage. A new 130mph shingle roof for my home will cost about $10,000 (high estimate). The low estimate from Tesla(10.1kw system with three Powerwalls) was $63 grand.
So $53,000 difference. I use roughly $2k/yr Probably less. So it will take 21 yrs to "break even.... Not so fast. The powerwalls are guaranteed for 10 yrs. No one has an issue with that math? And the degradation of the system is 5% in the beginning and then "only" .5%/yr after that...none of that was figured into the equation.
And instead let's just put the $43,000 in a safe stock... 3% annual return.... How far out does that push the ROI when you consider the money spent would have been making money for a prolonged number of years? Did you subtract the main benefit of the powerwalls after 10 years? When does that benefit go away? It is going to go away before 20 years. And then need replacing. So your overly-simplified ROI needs to Recover the new Powerwalls.
And then there is the outages due to hurricanes. A huge benefit/consideration for many of us on the SE Coast.... the roof is only rated to 130mph. And that is the point at which it would blow away. Likely, long before that, hurricane-driven rainwater intrusion would takedown the system. I tried to get more information from my contact person at Tesla as to whether the roof was robust enough to handle water intrusion in regard to maintaining viability of the system. I asked for everything they had on the subject. All they quoted was the wind rating. Which isn't any better than the shingles I had blow off my roof twice in the last 10 years. So the electrical system is suspect in a storm. If it doesn't work then what? A huge reason to get the roof is to have quiet energy when there is a power outage. You know, Peace of Mind. And you'd have to just drink the Kool-aid, and ignore the issue. Or you could get a whole house propane generate wired in for less than $8,000. Or you could just leave for a week and go on vacation, just be sure and empty the fridge before you go.
So ALL the "peace of mind" value has not been substantiate or proven over time in regard to a hurricane along the Southeastern United States.
And there is the other area to consider. We hear it every day. renewable energy is on a technological-breakthrough missile. "Renewable energy is getting cheaper." And if that isn't enough, look at Tesla Solar Roofing itself.... They tout the dramatic price drop. Do you think that is going to stop anytime soon. Some of us are forward-thinking enough to look to the "Announcement" Big Ee is going to have within a month concerning the battery sector of Tesla. Anyone think that this won't involve powerwalls directly, and the whole renewable energy arena indirectly? So how quick will the whole Solar glass/powerwall system become a dinosaur, and "You really should replace that" is going to be all you can think of when you look at your home?
And lastly, they state that the roof looks beautiful.
"No, No it doesn't." In that case I should be allowed to tar my roof and be done with it. "Tar is beautiful." Riiiight.
I even investigated just getting the Solarglass roof and not the powerwalls. My Tesla contact told me that the solarglass roof would not run the house if there was a grid outage. I would need the powerwalls to complete that. Having electricity through the sunny part of the day would make the home livable. But nope....no "outage" benefit to a $40,000 solarglass roof during a power outage even if the sun is shining.
SO yeah, if you live where electricity is 3x what I pay for it then perhaps it makes sense.
I'm still going to get my Cyber Utility Vehicle (with the vault, not a bed..though I will put a bed in the vault more often than I put anything else in the vault it is a vault, not a bed.). Right now I am in it for the 2M model. I've never been one to go as fast as the car will go so what is the point of having that much speed).
I could buy the highest priced Cyber with all the bells and whistles for what I was quoted for the "Max Solar" system for my 980 sq ft home. think about that for a second.
I've run the numbers for the cyber, and they seem legit. I will charge the Cyber at night. And sleep in it if there is any power outage, especially a hurricane. So it will have a great benefit as "The Hurricane Bunker.... Bulletproof, Air-conditioned, large bed, TV...sounds better than a noisy motel room 300 miles from home. I can sit right outside the house and watch the storm blow through. Maybe make a cool youtube vid. I wonder what the wind-rating on the Cyber is? Probably at least over 200mph, maybe 3 times what the Solarglass roof is rated.And it is going to weigh a ton (or a couple of tons), So it ain't going to go anywhere....unless I tell it to.
