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

#201

Post by legohead » Sat, Oct 26, 2019, 4:12 PM UTC

bArray wrote: post #22

I think a major challenge that is yet to be addressed is the fact that solar panels lose their efficiency over time [1] [2]. Seems like you're looking at 80% of rated efficiency after 20 years - and I'm unsure this includes failures. In the UK a 50+ year old roof is very common - most people expect a house to outlast them without anything but minor repairs. If I were building a house I would want something where it's…

What about anything you said is a "major challenge"?

They lose efficiency, yes everyone knows this and can plan ahead. They can fail like anything else.

But they can be re-used and replaced. If you need to replace your roof, you just remove them and re-install on the new roof.

There's no magic to installing them, it's quite simple if you have any handyness. If not, just hire someone like anything else.

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

#202

Post by macspoofing » Sat, Oct 26, 2019, 4:13 PM UTC

mepiethree wrote: post #185

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…

> solar needs the grid to be even close to viable This was true 20 years ago and will be laughable 20 years from now. > The only power generators that can do that are ones that burn fossil fuels. Fossil fuel generators do NOT ramp up and down quickly. BTM and FTM battery storage solutions ramp up and down faster and are rapidly becoming cheaper and more environmentally friendly alternatives. > energy use in building…

>This was true 20 years ago and will be laughable 20 years from now.

Will the sun start shining at night in 20 years?

>Fossil fuel generators do NOT ramp up and down quickly.

Natural gas ramps as quickly as it can. But let's assume that's true, that's not a point against me, it's a point against solar because then it means that solar is completely unworkable.

>Every one of these supposed drawbacks of solar also apply to generating power with fossil fuel.

No. Because we know we can power an economy with fossil fuels, and do it in any weather, day or night.

>Fracking causes earthquakes in Oklahoma and wastelands in southeast New Mexico.

Yes. Natural gas isn't great.

>In my view, human addiction to electricity is bad in all forms, but fossil fuels are clearly worse.

Right. That's why we need to get off fossil fuels. But you can't do that with solar or wind.

Here's what works: Nuclear, Hydro, Geothermal - that's basically it and the latter two need particular geography to be viable.

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

#203

Post by macspoofing » Sat, Oct 26, 2019, 4:15 PM UTC

mrep wrote: post #199

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…

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)"

>Or you use batteries which is in the default option.

What batteries? Hate to break it to you, but there is no battery technology capable of storing enough energy to bridge solar intermittency gaps at even the scale of a city.

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

#204

Post by HeWhoLurksLate » Sat, Oct 26, 2019, 4:15 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…

> Who is going to hire some rando non-english speaking guys from the 7-11

You know you didn't have to put non-english speaking in there, right? Totally unnecessary and shows potential racial bias.

(I'm not perfect either, and it bugs me when I say stuff like that too.)

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

#205

Post by jacquesm » Sat, Oct 26, 2019, 4:16 PM UTC

Retric wrote: post #195

new_realist wrote: post #192

Earlier quoted context omitted.

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 disch…

> daily solar output never drops to zero

True, but it is also almost never 'rated power'. Typically a solar installation will deliver somewhere between 30 and 50% of rated power on average, depending on your latitude it might be even lower. The times when solar panels work at their best is during clear winter days and when they are capable of two axis adjustment. Because of the cost of such an installation the typical choice is to install more panels running at lower efficiency.

And you'd need to size your batteries for those worst case scenarios of obscured sub in which case your panels might only output between 5 and 10% of their nominal capacity.

For reference, my 1600W array is outputting 15.9 Watts right now, earlier, at the best time of the day it was making about 300W due to the sky being overcast. If I had to rely on battery power to make up the difference I would not be able to make it on solar alone.

A healthy mix uses both solar and windpower, hydro if you have access to it (it is by far the most stable of the three and capable of providing baseline power without any tricks).

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

#206

Post by nostrademons » Sat, Oct 26, 2019, 4:17 PM UTC

BlueTemplar wrote: post #138

abootstrapper wrote: post #108

Earlier quoted context omitted.

I agree we should put the breaks on urban sprawl, but the US is already spread out. I mean what’s more feasible: Have all current suburbanites sell their house, move downtown, and have their old property leveled OR get them driving an EV?

The first one, at least for the next decades. (We don't have enough resources for the second option - due to the required number of batteries. )

We don't have enough housing or mass transit for the first option, and building more batteries has proven significantly easier than building either more housing or more transit.

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

#207

Post by SlowRobotAhead » Sat, Oct 26, 2019, 4:17 PM UTC

rco8786 wrote: post #23

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…

Traditional roof PLUS solar panels

50 year premium traditional roof plus solar panels.

Headline is about as misleading as could be.

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

#208

Post by jacquesm » Sat, Oct 26, 2019, 4:18 PM UTC

pgl wrote: post #29

rjkennedy98 wrote: post #25

> It also lists $33,950 as the price after an $8,550 federal tax incentive. There is something absolutely astonishing about the fact that in America the way we have go about being eco-friendly is to give huge tax breaks to rich people to buy solar panels and electric vehicles. To think with all that money we could build better infrastructure and denser housing. Really boggles the mind.

Really? Isn't that how all successful technology starts off - highly priced, effectively experimental, but then becoming more and more available to the general public as the price goes down and production increases?

Solar is a solved problem. Anything that wants to displace regular panels has to do so by improving on them.

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

#209

Post by rory096 » Sat, Oct 26, 2019, 4:19 PM UTC

robocat wrote: post #181

rory096 wrote: post #62

Earlier quoted context omitted.

>Grid scale solar is significantly cheaper due to the economies of scale. Utility scale solar has met the same ardent opposition in land use decisionmaking fora as denser housing, including from 'environmental' organizations. Some examples from around here: https://fredericksburg.com/news/local/culpeper/culpeper-coun... http://lakegastongazette-observer.com/news/article_8f621d6e-... https://richmond.com/news/local/ce…

Summary of 5 links: 2 projects cancelled due to NIMBY, 1 project being appealed due to NIMBY, 1 project cancelled due to ecological concerns (unclear if just NIMBY), 1 irrelevant link. fredericksburg.com - application cancelled - "He, like other neighbors of the project and another larger one south of Stevensburg, have consistently expressed concerns about impact to their property values ... Orye said he didn’t think…

>www.pecva.org - looks like last link just shows planning details and doesn't show opposition.

They oppose utility-scale solar anywhere except existing industrial land, in favor of the "low hanging fruit" of rooftop solar.

>PEC is an advocate for solar energy, especially distributed solar power generation - small scale solar (usually rooftop) primarily designed to meet the immediate demands of the property in which it is located. In comparison, the size and nature of USS Facilities create challenges for any locality to protect important resources and the public health, safety, and welfare of the community. Virginia has thousands of acres of rooftops, parking lots, and landfills devoid of solar panels in areas of moderate to high energy demand, in addition to contaminated and/or underutilized industrial sites. It is PEC’s belief that we should be looking to these developed areas as the low hanging fruit of future solar sites.

>Utility-Scale Solar (USS) Facilities are industrial facilities and should not be allowed by-right on agriculturally zoned lands. Given their size and nature, they should be:

>● Subject to a Conditional or Special Use Permit in agriculturally zoned areas with maximum acreage allowed per project and possibly per the entire County; and/or

>● Limited to existing industrial zoned areas.

> ○ Agricultural land should not be spot zoned to create additional industrial zoned areas for USS Facilities.

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

#210

Post by dclusin » Sat, Oct 26, 2019, 4:20 PM UTC

mepiethree wrote: post #148

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…

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…

The utility companies also have to deal with excess capacity created by solar, typically by selling at a loss to other states. This shortfall is then made up by other customers, which as a demographic, tend to be poorer than solar panel owners.