171–180 of 290 posts
Pet peeve: meaningless projections into the far future. The "battery prices keep tumbling" chart is a complete fiction. They took two data points and extrapolated a smooth e^-x function, which portrays a untruthful appearance of accuracy. Two points fit whatever curve you want to fit. Including this graph is worse than having nothing. Question: how would I complain to Bloomberg about this?
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…
The 30% tax credit for solar installations may well be adjusted. These kinds of things are not so absolute.
http://news.energysage.com/congress-extends-the-solar-tax-cr...
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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.
> 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…
Also, I grew up in the Northeast. Snow slides right off steel roofing. It sticks to shingles, especially if you have any ice build-up. Unless you have a relatively steep roof pitch, you have to get up on the roof in the winter and clear the snow off. With steel, you wait for a warmer day, and it slides on its own.
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I think this is exactly right. There is some fudging with the cost (this seems to be a common theme with Elon) by pre-including savings and rebates Etc, but the fact is this makes a solar roof something different than a set of panels across an existing roof. The durability question, and the weight per sq foot will be interesting. That said, the combination of the PowerWall and the roof might actually make it more ame…
Tar shingles are pretty damned heavy. If you've never experienced it, try picking some up at your hardware store, they have a bit of a weigh budget to work with. And then if you want some sympathy for your roofers, imagine slinging a box of those while standing on a diagonal surface 20 feet in the air in the afternoon sun. Yikes. I'd almost worry more about about the size of the panels making installation problematic…
Nowhere close to mining coal of course.
http://www.forbes.com/sites/jamesconca/2012/06/10/energys-de...
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…
You think this happens with modern panels? Even low estimates put the EROI at something more like 4, with other people figuring 15-20 (of course it depends on where they are installed. EROI is better in Phoenix than Seattle).
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…
I think this is exactly right. There is some fudging with the cost (this seems to be a common theme with Elon) by pre-including savings and rebates Etc, but the fact is this makes a solar roof something different than a set of panels across an existing roof. The durability question, and the weight per sq foot will be interesting. That said, the combination of the PowerWall and the roof might actually make it more ame…
I'm curious if anyone has stats on what percentage of houses have an unobstructed southern roof (for those in the Northern hemisphere)? My house has seasonally adjusted nanotechnology self-replicating shade "panels" that block considerable sunlight in the spring and summer months (MTBF: 100+ years). The big downside is cleaning up the unused panels in the autumn.
Does that mean I get a perfect peak output during the middle of the day? No. But my generation comes on earlier and off later than friends with perfectly aligned systems - which without a powerwall (sadly don't have one yet) that is a benefit expanding the amount of time that I am generating usable power and saving A$0.25c/kWh instead of earning $0.06/kWh for exporting it at peak generation. (fair that in this context we're looking at potentially having a power wall too, but never the less - you lose round-trip efficiency on batteries - about 10% - it's likely to end up fully charged anyway depending on your daytime usage and thus extending your generation time might still be good).
I have 3.5kW of panels (3kW inverter, the max I can get on a single phase supply) and hit about 2.75kW peak generation . I wouldn't mind adding another panel or two per string (on my particular inverter and due to having two parallel strings, it works out fine for the voltages.. but this can vary a lot depending on your system specifications)
But also - seriously, the aesthetics. My suburb (Baldivis, Western Australia) has one of the top solar penetrations in the entire country at 57% of all houses (you can see here, it's 5th on the list: http://reneweconomy.com.au/australias-top-solar-states-and-s...) -- and while they're not exactly drop dead UGLY - it sure would be prettier with roofs like this everywhere. Particularly here we have a lot of smaller houses in orientations which mean often they end up being street facing instead of not. So yeah. Not sure how much of a greenhouse effect your roof is going to end up with though, that will be interesting. (here, we have predominantly tile or tin roofing - this shingle like stuff is much less common here than other parts of the world from what I've gathered)
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Another side note: it always annoys me when people insinuate that Musk using government funds is a bad thing. The government is literally just US....it's our money and a collection of individuals from among us who we've appointed to handle the general administration of us and the space we take up. Why should American entrepreneurs, particularly ones doing such an outstanding job of moving technology in a positive dir…
The government is not literally just 'us.' It's a contentious idea: "government is just the word for the things we choose to do together" was oft-repeated by Rep. Barney Frank. He was repeating it because not everyone agrees. I think the primary problem of government funding is waste and the potential for corruption. Waste because the government is more immune to profit motive and thus can throw good money after bad…
Definitely contentious. A more correct formulation is "government is just the word for the things we are forced to do together"
Alright, fine, how long until Tesla launches satellite power systems?
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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.
It might be better to say that home PV and EV and battery storage go hand-in-hand (since that allows you to dump your surplus battery into your car at night), which appears to be Tesla's strategy. It would help if the battery storage were big enough to fully recharge an EV, but that's not strictly necessary unless you do a lot of driving. Solar panels on cars are another option. I used to think that was a bad idea, c…