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No One Saw Tesla’s Solar Roof Coming

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Re: No One Saw Tesla’s Solar Roof Coming

#191

Post by tux1968 »

redcap wrote: post #184
philipkglass wrote: post #153

Earlier quoted context omitted.

1) Anthropogenic CO2 emission rates in 1990 were greater than natural sinks could offset. 2) Under any reasonable set of assumptions, rooftop solar PV has significantly lower emissions per kWh than the cleanest fossil sources. In 2014 the IPCC estimated a median value of 41 gCO2-e/kWh for rooftop PV generation vs. 490 for combined cycle natural gas generation. 3) Perhaps some of the CO2 avoidance will be squandered e…

2) Does that include the carbon cost of manufacturing, distributing and installing the tiles?

You have to manufacture, distribute, and install tar shingles too. Is there some reason to think these costs would be higher for solar tech?

Re: No One Saw Tesla’s Solar Roof Coming

#192

Post by philipkglass »

josinalvo wrote: post #185
brownbat wrote: post #174

Earlier quoted context omitted.

Solar, surprisingly enough, has a higher death per kilowatt rate than nuclear, primarily because roofing work is so dangerous. Nowhere close to mining coal of course. http://www.forbes.com/sites/jamesconca/2012/06/10/energys-de...

I've heard these numbers from Forbes come from a very pro-nuclear estimate. Does anyone more knowledgeable care to comment? What other estimates are there? How are they calculated?

I would like to see the original inputs that went into the calculation myself. I've searched quite a bit without being able to locate them. As far as I can tell, it's calculated by dividing the (very low) number of acute fatalities from civilian nuclear accidents by the (very high) number of terawatt hours generated by civilian nuclear power plants. If I'm correct that would kind-of be cheating because they're not counting "mundane" fatal accidents (forklift crushing, arc flash, falls from high places, etc.) that also happen on nuclear sites. The spirit of the comparison that fossil combustion is far more dangerous to human health than nuclear power is correct, but the exact number given for nuclear may be a bit too low.

Additionally, I'd like to see fatality numbers for solar overall, not just rooftop solar. In the US at least more solar capacity is installed at ground-mount plants than on rooftops. The rooftop number itself could probably use an update; increasing module efficiency, if nothing else, is going to reduce the number of rooftop trips required for a given capacity, hence the number of accidents per terawatt hour.

Re: No One Saw Tesla’s Solar Roof Coming

#193

Post by danieltillett »

lathiat wrote: post #181
anexprogrammer wrote: post #168

Earlier quoted context omitted.

> roofs are replaced by the majority of insured homeowners every 10 years or less Well I was going to be astonished, but Google and Wikipedia seem to tell me US roofs are a consumable and usually asphalt! Most UK roofs are tile, slate if older, and asphalt shingles reserved for sheds, garden structures etc. Tile lifespan should be 60+ years. As much as I like the improved aesthetics I don't see the tiles making much…

that's bananas, in Australia replacing a roof is really uncommon. much like the poster above in the UK it's usually either corrugated "tin" (actual metal varies) or Terracotta/concrete tiles. We don't really have any of the "shingle" type stuff. The "Tuscan" glass tile from the Tesla event is the closest looks to the most common tiles here.

You normally don't replace a tile roof unless you get hit by a big hail storm. If these glass tiles hold up to hail better than tile then they would be good fit here.

Corrugated iron rusts out, but it has a pretty long lifespan.

The bigger issue is in many areas you are restricted in what roof material you can use - lots of locations limit you to tiles only.

Re: No One Saw Tesla’s Solar Roof Coming

#194

Post by plaguuuuuu »

lutorm wrote: post #7
sremani wrote: post #2

Roof top solar is critical for electrification of transportation since more demands would be placed on grid. SolarPV and EV go hand in hand. This product addresses many of the objections about aesthetics of Solar. TSLA has solid vision, hopefully they execute it and execute it well.

Home PV and EV doesn't go hand in hand for everyone that uses their EV to commute to work, though. I guess that represents a significant fraction of the vehicle park.

Not a huge amount of people commute >150mi

Re: No One Saw Tesla’s Solar Roof Coming

#195

Post by redcap »

tux1968 wrote: post #191
redcap wrote: post #184

Earlier quoted context omitted.

2) Does that include the carbon cost of manufacturing, distributing and installing the tiles?

You have to manufacture, distribute, and install tar shingles too. Is there some reason to think these costs would be higher for solar tech?

I presume there's a difference in manufacturing between these tiles and normal tiles.

I also presume there's CO2 costs involved in manufacturing solar cells that aren't present in normal shingles.

Re: No One Saw Tesla’s Solar Roof Coming

#196

Post by cdelb »

Graphon1 wrote: post #169
slfnflctd wrote: post #45

Earlier quoted context omitted.

Roof replacement is quite a dirty business, in more than one sense of the term, and there are regions where whole roofs are replaced by the majority of insured homeowners every 10 years or less. Any dent that can be made in this problem is a good thing, and this looks to be quite a large dent indeed.

> there are regions where whole roofs are replaced by the majority of insured homeowners every 10 years or less. cite?

In coastal regions of the PNW it is not uncommon to see moss and algae growth start within 3 years of a roof being installed. Replacement can be necessary within 10 years if the problem isn't dealt with.

source - owned a roof cleaning company.

Re: No One Saw Tesla’s Solar Roof Coming

#197

Post by WalterBright »

Retric wrote: post #164
adriancooney wrote: post #152

Earlier quoted context omitted.

Its a dodgy business though converting your entire roof to this technology (in its first iteration too). What if a tile breaks? Whats the lifetime on each tile?

Thick glass tends to be fairly resilient so anything that's going to damage these would likely destroy normal tiles anyway. Depending on how modular these things are they should be able to deal with breaks without significant problem just run in parallel like the good Christmas lights which still work when one goes out.

I had a ceramic roof once. Walking on the roof would break the tiles. It made it hard to do maintenance on anything up there.

My preference these days would be for a metal roof.

Re: No One Saw Tesla’s Solar Roof Coming

#198

Post by matt_kantor »

wtvanhest wrote: post #170
wojcech wrote: post #38

I'm sure i'm not the only one who feels like this is possibly the iphone moment of Solarcity/Tesla: an old-ish idea, made sexy and tasty to consumers, together with technology reaching a tipping point(and also Musk again finding a way to maximally exploit government subsidies for clean tech.) The tesla car itself could count as well, but felt less "design driven" imo. If this fails, everyone will call it obviously du…

I guess what confuses me is that most people with enough money to drive a Tesla keep it in a garage. I guess most offices probably don't have parking garages in suburbia, but I was surprised to hit control F "garage" on these comments and not see a single mention... There are lots of upsides for future research and gained efficiency in the future though. Especially as electric moves toward big trucks down the road. (…

Your comment is what confuses me. Can you explain how keeping a Tesla car in a garage is related to the parent comment about Elon's product design/marketing/business strategies?

Re: No One Saw Tesla’s Solar Roof Coming

#199

Post by jernfrost »

tajen wrote: post #146
philipkglass wrote: post #22

I had serious misgivings when Tesla/SolarCity announced a switch of focus to building-integrated PV. Historically, BIPV is where a PV technology goes to die after it's failed to compete against incumbent module designs. But these have far better aesthetics than previous BIPV efforts. They look better individually and they aren't clumped in one odd shiny patch on the roof like past BIPV. Search for images of solar shi…

But is it carbon-neutral now? Let's remind the whole picture here: We want to come back to global greenhouse gases emissions on 1990, because they were balanced by nature's absorption. It often happens that the cost of building solar panels, transporting them to the location, disposing them before their estimated time-to-live and getting rid of all their chemicals emit more carbon than we save by using electricity fr…

As far as I know consumer electricity usage has been on a downward trend for a long time.

Computers, TVs, washing machines etc are increasingly using less power. I think there are limits to how much we can waste. E.g. when food prices drops to half we don't buy twice as much food.

Re: No One Saw Tesla’s Solar Roof Coming

#200

Post by patrickg_zill »

majewsky wrote: post #142
patrickg_zill wrote: post #115

Asphalt shingles need to be replaced, depending on climate and other factors that cause them to degrade, every 10(?) to 20 years. Thus at least 5% of the total roofing market in existing residential houses, is a potential customer each year.

Assuming that everyone uses asphalt shingles, which is definitely not the case. For example, the German Wikipedia article for asphalt shingles describes them as "a typical GDR roofing". Germans tend to prefer clay/ceramic tiles on their homes, which can easily last 50 years and more.

The asphalt shingles are very popular in the USA, which is what I assumed their first market would be, since contractors apparently have to be trained in their installation.
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