Tesla’s new Solar Roof costs less than a new roof plus solar panels • Hacker News Board

Re: Tesla’s new Solar Roof costs less than a new roof plus solar panels

#191

Post by lscotte » Sat, Oct 26, 2019, 3:55 PM UTC

dx87 wrote: post #12

I wonder where they're getting their average price from, because I've never heard of a new roof and solar panel installation being that expensive. EDIT: They're comparing it to concrete roof tiles, which a quick search say that they last for ~50 years, twice as long as the warranty for the Tesla solar roof. https://www.tesla.com/solarroof/design

Definitely, the solar price in that article is twice what I paid for my 9.4KW system. I wouldn't have gotten Tesla anyway, even if it was cheaper. This is not the sort of place I'm willing to be an early adopter - once they have proven they have decades of experience, like SMA and others, then maybe. Until then, no way.

Re: Tesla’s new Solar Roof costs less than a new roof plus solar panels

#192

Post by new_realist » Sat, Oct 26, 2019, 3:59 PM UTC

reustle wrote: post #184

macspoofing wrote: post #172

Earlier quoted context omitted.

> If too many people build solar, the utility can't build new infrastructure and charge everyone for it. Right. Because solar does not play well with existing infrastructure but solar needs the grid to be even close to viable. It needs it because it is a diffuse intermittent power source, where the peak power generation does not actually match peak power use. Solar overproduction cannot be saved for later either, mea…

I may be misunderstanding but it seems like most of your comment completely ignores batteries?

Batteries double the cost of solar for a 24 hour storage cycle. If you want to store energy for 48 hours, the cost doubles again. 96 hours? Doubles again. Want to store a mere 10% of US electrical generation from summer to use in winter? Literally 52 trillion (yes, trillion) dollars if you use batteries. A bit expensive, even if you spread the cost over 25 years. Pumped hydro, CAES and hydrogen stored in salt caverns are much cheaper at that scale.

Re: Tesla’s new Solar Roof costs less than a new roof plus solar panels

#193

Post by cowsandmilk » Sat, Oct 26, 2019, 4:03 PM UTC

IshKebab wrote: post #190

dx87 wrote: post #12

I wonder where they're getting their average price from, because I've never heard of a new roof and solar panel installation being that expensive. EDIT: They're comparing it to concrete roof tiles, which a quick search say that they last for ~50 years, twice as long as the warranty for the Tesla solar roof. https://www.tesla.com/solarroof/design

Warranty is different from how long something will last.

So, should we expect the Tesla roof, which has historically had so many issues that they’ve done very few installations, to suddenly be able to last 50 years?

Re: Tesla’s new Solar Roof costs less than a new roof plus solar panels

#194

Post by serpix » Sat, Oct 26, 2019, 4:04 PM UTC

t34543 wrote: post #21

aphextron wrote: post #11

Earlier quoted context omitted.

> Cheaper than traditional roof plus solar. I find that really hard to believe. A new roof runs between 5-10k, and a 3kw solar system can be had for ~5k + labor. Even if they are including a power wall in that price it's still pretty steep. Edit: It looks like they are actually quoting a 10kw system with 3 power walls (~40kwH storage) included, which at that point sounds about right at $40k. Still far beyond the reac…

Roofs in my area are 20k for 1200 sq ft. Asphalt shingles. I would love to live in an area where it’s 5-10k.

I paid 30000 euros for roofing for a house a little bigger than that. I would have danced naked on the streets for 20k.

Re: Tesla’s new Solar Roof costs less than a new roof plus solar panels

#195

Post by Retric » Sat, Oct 26, 2019, 4:05 PM UTC

new_realist wrote: post #192

reustle wrote: post #184

Earlier quoted context omitted.

I may be misunderstanding but it seems like most of your comment completely ignores batteries?

Batteries double the cost of solar for a 24 hour storage cycle. If you want to store energy for 48 hours, the cost doubles again. 96 hours? Doubles again. Want to store a mere 10% of US electrical generation from summer to use in winter? Literally 52 trillion (yes, trillion) dollars if you use batteries. A bit expensive, even if you spread the cost over 25 years. Pumped hydro, CAES and hydrogen stored in salt caverns…

Only if you’re failing to build enough solar. There is zero reason to ramp up storage rather than reduce the need for it. Over production is cheaper than any other option and reduces the need for longer term storage as daily solar output never drops to zero.

Solar is cheap enough it’s still cost competitive if you assume significant power production is wasted. Further, battery systems are designed to avoid full discharge, design for 99.5% of the time and you have spare capacity for the last 0.5%.

Re: Tesla’s new Solar Roof costs less than a new roof plus solar panels

#196

Post by legohead » Sat, Oct 26, 2019, 4:06 PM UTC

Quequau wrote: post #91

I have a friend in America who has a fairly large PV set up on part of his property. Listening to the all the obstacles he's had to overcome and all the surprising limitations he's saddled with, I can't help but suspect that the power company in his area that he's selling the power to would rather that these sorts of installations simply not exist. Coupling that with the fact that off-peak pricing isn't the norm in a…

Where does he live? Some states are surprisingly anti-progressive. California actually has measures to help people install solar (since 1979!). Things like HOAs can't deny your installation based on aesthetics, and anything under 10KW is allowed with very little oversight.

Re: Tesla’s new Solar Roof costs less than a new roof plus solar panels

#197

Post by jacquesm » Sat, Oct 26, 2019, 4:10 PM UTC

macspoofing wrote: post #172

mepiethree wrote: post #148

Earlier quoted context omitted.

The profit model for utility companies is to build new power plants, power lines, and substations, and charge their rate payers for that build ("rate base" it). Then they get a cut of their expense as profit. If too many people build solar, the utility can't build new infrastructure and charge everyone for it. And, they now have to manage balancing solar production with electricity usage, which means hiring new analy…

> If too many people build solar, the utility can't build new infrastructure and charge everyone for it. Right. Because solar does not play well with existing infrastructure but solar needs the grid to be even close to viable. It needs it because it is a diffuse intermittent power source, where the peak power generation does not actually match peak power use. Solar overproduction cannot be saved for later either, mea…

The only fossil fuel generators that ramp up and down quickly are the ones burning natural gas powering turbines. The rest is rather sluggish. And Nuclear is terrible at this too, especially at load shedding, which can cause a plant to be shut down after which it will take up to 72 hours to power back up.

Re: Tesla’s new Solar Roof costs less than a new roof plus solar panels

#198

Post by cowsandmilk » Sat, Oct 26, 2019, 4:11 PM UTC

tgtweak wrote: post #89

wil421 wrote: post #6

> Tesla’s Solar Roof website now includes a pricing estimator, which lists $42,500 as the total price for the average 2,000 square-foot home, with 10kW solar panels. It also lists $33,950 as the price after an $8,550 federal tax incentive. You can also enter your address and get an updated estimate that takes into account local costs and incentives, and add on any Powerwalls (with three as the default for a 2,000 squ…

You could reshingle a roof for $3.50/sqft and it's not unheard of to get traditional solar installed at $1.50/W, ~$15,000 for a 10kw system. $7000 + $15,000 Then you apply the federal credit after that. This is for a grid-tie system, I don't think Tesla is pricing theirs with a powerwall here. Edit: apparently they're pricing it with 2 powerwalls, still cheaper by a sizeable margin however.

> Edit: apparently they're pricing it with 2 powerwalls, still cheaper by a sizeable margin however.

Their price comparison doesn’t include the powerwalls from what I can tell...

Re: Tesla’s new Solar Roof costs less than a new roof plus solar panels

#199

Post by mrep » Sat, Oct 26, 2019, 4:11 PM UTC

macspoofing wrote: post #172

mepiethree wrote: post #148

Earlier quoted context omitted.

The profit model for utility companies is to build new power plants, power lines, and substations, and charge their rate payers for that build ("rate base" it). Then they get a cut of their expense as profit. If too many people build solar, the utility can't build new infrastructure and charge everyone for it. And, they now have to manage balancing solar production with electricity usage, which means hiring new analy…

> If too many people build solar, the utility can't build new infrastructure and charge everyone for it. Right. Because solar does not play well with existing infrastructure but solar needs the grid to be even close to viable. It needs it because it is a diffuse intermittent power source, where the peak power generation does not actually match peak power use. Solar overproduction cannot be saved for later either, mea…

Or you use batteries which is in the default option. From the article "You can also enter your address and get an updated estimate that takes into account local costs and incentives, and add on any Powerwalls (with three as the default for a 2,000 square-foot roof)"

Re: Tesla’s new Solar Roof costs less than a new roof plus solar panels

#200

Post by SlowRobotAhead » Sat, Oct 26, 2019, 4:11 PM UTC

jandrese wrote: post #142

rco8786 wrote: post #26

Earlier quoted context omitted.

> new roof runs between 5-10k, That is incredibly cheap if so. That would be a roof on a small barn around here.

If you shop around it's abundantly clear that the price of a new roof varies wildly. Some of it is materials. The guy offering 50 year warranty GAF super-premium install who spots loads of potential problems up front and factors them into the cost is going to run much higher. The guy who is just going to hire some rando non-english speaking guys from the 7-11 and toss on the cheapest possible materials without concer…

> The guy who is just going to hire some rando non-english speaking guys from the 7-11 and toss on the cheapest possible materials without concern about the underlying structure is going to be like a 1/4 of that price.

You’ve met my guy Serge! He’s actually quite good and I’ve used him on two different houses. He probably has twice the experience of the super premium guy in town.

It’s mostly nailing rocky tar sheets to wood, the guy who has done it a billion times (literally?) sometimes might be the better choice over the guy who bought into an exclusive contract with super premium company and went to their special school for the special product.