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Post by anonposter on Jun 10, 2013 7:03:59 GMT 9.5
Putting solar panels on the roof of a car will do almost nothing to help (unless you want to leave your car outside for months at a time without starting it).
Remember that solar powered cars are stunts with exceptional aerodynamics, very light weight, limited room, basically no luxuries (or safety features other than a seat belt for that matter) and even then require a clear sky near the equator to be workable (am I the only one who has noticed that those big solar car races tend to be in deserts in the summer?) with most of them being unable to keep up with freeway traffic.
Now demand that four people fit in it comfortably, add air-conditioning, put some airbags in, give it crumple zones and some extra structural strength (practically every ad for new cars these days mentions five star safety) and see how useful it is (I'm assuming that people will be willing to give up the SUV look, if they're going to insist on it looking like it can go off-road things will be even worse).
And then if you need the car at night or on a cloudy day (or even just winter) you'll need some batteries making the car even heavier (especially if you insist on being able to drive a decent distance when the sun isn't shining or shining very strongly).
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Post by huon on Jun 17, 2013 8:16:34 GMT 9.5
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Post by edireland on Jun 17, 2013 9:34:37 GMT 9.5
And using it repeatedly will cook the battery in a couple of years.
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Post by huon on Jun 17, 2013 16:41:13 GMT 9.5
Here is what Tesla has to say about Supercharging the Model S battery: " How often can I Supercharge, is it bad for my battery?Supercharging does not alter the new vehicle warranty. Customers are free to use the network as much as they like." www.teslamotors.com/superchargerThe battery warranty is for 8 years and unlimited miles, so the company has some incentive to give accurate advice.
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Post by edireland on Jun 17, 2013 18:07:16 GMT 9.5
That just means they are willing to replace the battery when it gets cooked. It is effectively impossible to build a lithium ion battery that can survive that level of abuse on a regular basis and maintain anything near its full capacity for 8 years.
Tesla have a whole business model about buying replacement batteries in advance.
And thats before we consider the implications for the grid of intermittant several hundred kilowatt draws appearing and dissapearing at near random intervals in near random locations.
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Post by huon on Jun 18, 2013 16:59:55 GMT 9.5
It will be interesting to find out how much the Tesla batteries are degraded by fast charging. But because of the warranty, for owners it's rather a moot point. As for stress on the grid, many of the charging stations will be equipped with solar roofs and half-megawatthour batteries. That should help even out the load, and as Elon Musk points out, will also make the chargers robust (even in a "zombie apocalypse"). green.autoblog.com/2013/05/30/tesla-supercharger-network-goes-nationwide-gets-faster-w-video/
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Post by anonposter on Jun 18, 2013 17:41:16 GMT 9.5
It will be interesting to find out how much the Tesla batteries are degraded by fast charging. But because of the warranty, for owners it's rather a moot point. Provided Tesla stays in business.
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Post by edireland on Jun 19, 2013 3:08:00 GMT 9.5
It will be interesting to find out how much the Tesla batteries are degraded by fast charging. But because of the warranty, for owners it's rather a moot point. As for stress on the grid, many of the charging stations will be equipped with solar roofs and half-megawatthour batteries. That should help even out the load, and as Elon Musk points out, will also make the chargers robust (even in a "zombie apocalypse"). green.autoblog.com/2013/05/30/tesla-supercharger-network-goes-nationwide-gets-faster-w-video/ And means that it costs Elon Musk nothing to deploy this infrastruture, since its a giant subsidy farm.
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Post by huon on Jun 20, 2013 12:50:43 GMT 9.5
@anon A fair point. edireland According to the autoblog story, the cost of a Tesla charging station is US$150,000 without solar and US$300,000 with. Incidentally, on Thursday Tesla will demonstrate a battery swap for the Model S. And on Saturday, the Le Mans race will feature hybrids from Toyota competing with those from VW/Audi. Should be fun.
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Post by Roger Clifton on Jun 22, 2013 13:39:41 GMT 9.5
many of the charging stations will be equipped with ... half-megawatthour batteries. I imagine that the grid operator might require the charging stations to have such a battery to limit the ramp on and off the grid. Considering that vehicle fueling stations are distributed widely across the community, the idea that each of them should have a multi-MWh battery does seem to provide the "distributed storage" that the "distributed generation" of solar and wind suggests. Any spare capacity at each station, such as between rush-hours, might be profitably dedicated to playing the local energy market. They might even be able to supply reaction-balancing power for their locality too. It might just be the market niche that brings forward the development of sodium-sulphur batteries. Such batteries, unlike lead and vanadium, do not permanently contaminate their environment after a spill.
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Post by edireland on Jun 22, 2013 20:49:25 GMT 9.5
All of these stations are going to need high power grid taps at atleast the 33kV level, especially once electric cars become more common. I am not entirely sure a half megawatt hour battery is going to cut it, and additionally the battery is going to be expensive, even if they are sodium-sulfur units. (And Imagine what NIMBYs would say about a concrete pad covered in batteries that are full of molten sodium)
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Post by Roger Clifton on Jun 23, 2013 10:53:44 GMT 9.5
The public is already well adapted to the presence of giant tanks of gasoline at fuelling stations scattered throughout the suburbs. It may not be too difficult to persuade them that a tank of sodium is safer than a tank of gasoline. I imagine they may come to be more offended by the faint sulphurous wisps and may even breathe a sigh of relief that at least it isn't the smell of explosive gasoline.
For most of us, we are only familiar with the burning of sodium as a scary experiment from school. But sodium doesn't gasify, so it gives no flame, it can't create a fire storm and given the use of standard containment structures, doesn't cause explosions. On the other hand we are endlessly witness to gasoline explosions on the news and in movies, but don't let that worry us enough to question our natural born right to ride around on a tank of gasoline to burn in our car. After all, many of us would believe if told that Adam and Eve were sired in the back of a V8 in the parking lot at the Garden of Eden.
Once people have gotten used to an uneventful track record of sodium presence in the community, they may think it ho-hum that the local power station itself includes a sodium immersion tank.
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Post by huon on Jun 28, 2013 16:36:58 GMT 9.5
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Post by huon on Jul 22, 2013 16:33:52 GMT 9.5
The new BMW i3 electric car looks quite promising. As a review on Top Gear indicates: The i3 proves that for a car that ducks and drives around a city or cruises at dual-carriageway speeds, electricity can feel like a beautifully appropriate power source....
At first sampling then, this is a compelling electric car. It's not the first on the market, but BMW has put some original thinking into almost every part of its design and engineering. It drives sweetly, is distinctively designed, and has the reassuring range-extender option if you are anxious about running flat.www.topgear.com/uk/car-news/BMW-i3-first-drive-2013-09-10
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Post by edireland on Jul 23, 2013 6:51:51 GMT 9.5
Still far too expensive.
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Post by huon on Jul 24, 2013 7:27:15 GMT 9.5
Yes, edireland, the price of electric vehicles must continue to come down.
But on the other hand, at 35,000 euros in the EU and $35,000 in the US (after a $7,500 federal credit), the i3 is pretty cheap for a BMW. And for a ground-breaking, premium electric car, it's a bargain.
Then throw in, say, $10,000 in savings on gas over 10 years, and you have a car well under $30,000. At this point the i3 starts poaching in the territory of best-selling family sedans.
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Post by huon on Aug 5, 2013 16:47:04 GMT 9.5
The debut of the BMW electric i3 was a success: www.plugincars.com/bmw-i3.html(Scroll down for the most recent articles.) To my knowledge, there is no other production car on the planet which can get 5 miles per kWh. A technological triumph.
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Post by huon on Aug 13, 2013 17:10:46 GMT 9.5
What do you get when you cross a Tesla car with a SpaceX rocket? A hyperloop, able to speed riders electrically from San Francisco to Los Angeles (around 400 miles) in about 30 minutes. It's just on paper at the moment, but still very interesting: www.greencarcongress.com/2013/08/hyperloop-20130812.html
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Post by edireland on Aug 14, 2013 7:16:17 GMT 9.5
Oh god, not this thing again. Its rubbish.
The report is shot through with lies and mistatements and drastically understates the cost. He also overstates the energy cost of HSR by almost an order of magnitude. TGV Duplex would do the 400 miles in ~2hrs with an energy cost of 20kWh per seat. So about $1-2.
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Post by huon on Aug 20, 2013 15:33:04 GMT 9.5
MIT's Technology Review has a fairly balanced assessment of the Hyperloop: ..."What [Musk] did that I think makes sense is he picked the sweet spot, where he'e trying to get the benefits of a vacuum but not go all the way to a hard vacuum," Hansman says. But maintaining low pressures will still require substantial amounts of energy, and exactly how much will depend on things such as how well the system can be sealed, he says. mashable.com/2013/08/13/musk-hyperloop-doubts/Perhaps if someone ever builds this, Texas would be a better site. It's flat, the land is cheap, and people already like double-barreled shotguns.
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Post by huon on Aug 26, 2013 15:41:54 GMT 9.5
I was going to do one more post on the Hyperloop, but today I found something even more interesting: a proposal for maglev vehicles in an evacuated tube. "But with ET3 [Evacuated Tube Transport Technologies], Oster appears to have, with the possible exception of Musk, developed the most detailed plans for tackling those 'manifold and difficult' problems associated with evacuated tube technology. There are three keys to ET3: a narrow tube diameter, minimal capsule weight and high-temperature maglev technology...." mashable.com/2013/08/25/hyperloop-daryl-oster/
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Post by edireland on Aug 26, 2013 23:04:52 GMT 9.5
And it costs an absurd amoutn of money for absolutely no benefit over more traditional transport technologies.
Its one of those nonsensical pipe dreams that will never go anywhere.
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Post by huon on Aug 28, 2013 8:36:28 GMT 9.5
edireland-- You're overly pessimistic about tube travel. The payoff is speed faster than a jet with energy consumption below that of an electric high-speed train. It may not be ET3 that does it, but surely someone, sometime will be able to pair evacuated tubes with high-temp maglev. As for cost, the ET3 website has this to say (FAQ, "Would creating tubes large enough to allow passengers to walk around be an option?"): "The cost of ET3 us very sensitive to the tube diameter. If the capsules were made 'as big as a bus' it would increase the cost by a factor of about 30.... "The most important thing to get correct with ET3 is the capsule diameter. If the diameter is a little too small ET3 will not achieve sufficient utility to carry most cargo and passenger comfort would suffer. If a little too big, the cost prevents maximum use. Our considerable research into this topic of optimal size indicates that the optimal capsule diameter is 1.3m (51") and the corresponding tube diameter is 1.5m (60")." www.et3.com/faqThe capsules must also be very light. I'll bet BMW, using the i3's new carbon fiber technology, could produce a great capsule.
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Post by edireland on Aug 29, 2013 3:11:53 GMT 9.5
edireland-- You're overly pessimistic about tube travel. The payoff is speed faster than a jet with energy consumption below that of an electric high-speed train. It may not be ET3 that does it, but surely someone, sometime will be able to pair evacuated tubes with high-temp maglev. The problem with all these technologies is making them not horrendously fail-deadly and at the same time delivering anything close to the capacity that more traditional systems can reach. Conventional HSR can put 1300 seat trains down a line 18 times per hour (if you go for Japanese seating densities you can get that figure up to 1800 seats). Delivering 23400 (or higher) seats per hour with an alignment as wide as a two track High Speed rail one is a massive challenge. Hyperloop simply couldn't manage it. The seat costs of HSR will simply be so much lower than these more exotic alternatives that noone takes them up on them despite the speed advantage. As for cost, the ET3 website has this to say (FAQ, "Would creating tubes large enough to allow passengers to walk around be an option?"): "The cost of ET3 us very sensitive to the tube diameter. If the capsules were made 'as big as a bus' it would increase the cost by a factor of about 30.... "The most important thing to get correct with ET3 is the capsule diameter. If the diameter is a little too small ET3 will not achieve sufficient utility to carry most cargo and passenger comfort would suffer. If a little too big, the cost prevents maximum use. Our considerable research into this topic of optimal size indicates that the optimal capsule diameter is 1.3m (51") and the corresponding tube diameter is 1.5m (60")." www.et3.com/faqThe capsules must also be very light. I'll bet BMW, using the i3's new carbon fiber technology, could produce a great capsule. That is going to be rather uncomfortable for the passengers, and it causes problems for escaping in a pressurisation loss accident. You have to be able to either get people out of the vehicles very rapidly or very rapidly repressurise the entire tunnel, or both. We are talking seconds to sea level pressure or we end up with serious problems in an accident, assuming you can have an accident that doesn't involve catastrophic death of everyone really quickly. And then you have to engineer all the tubes to contain teh debris from one of these catastrophic accidents. Hear that? That is the sound of the price shattering the ceiling.
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Post by huon on Sept 3, 2013 8:07:25 GMT 9.5
Capacity for ET3 vs. high-speed rail is given as 172,000 vs. 29,300 persons/hour, respectively. www.et3.com/rail-vs-ett . Safety considerations are covered in the FAQ section. Again, I don't know whether this particular venture will succeed--certainly one wouldn't bet even money on it. But I do hope that they build a prototype, as they outline on the home page: www.et3.com/
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Post by edireland on Sept 3, 2013 22:20:02 GMT 9.5
It has capsules seperated by 0.125 seconds moving at several hundred miles per per hour. At 700mph supposed 0.05 second seperations are practical which translates 15.6m apart moving at ~310m/s. As the vehicles are 4m long that takes us to 11.6m actual spacing.
That means that in order to not get catastrophic chain reaction pile ups a capsule would have to be able to slam on the brakes at something approaching 440g to avoid a collision.
So you can see this is rather ridiculous. With the same safety principles I could run railway trains with 30 second headways, and since this claims the full theoretical capacity is available for us and not 75% of it like the HSR example.... that takes me to 156,000 people per hour at the very least.
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Post by huon on Sept 7, 2013 8:54:39 GMT 9.5
edireland-- Thanks for the thought-provoking comment. Here's my quick take on the safety of ET3 tube transport (@ 500 km/h and 172,000 persons/hour). Suppose the capsules were aggregated into small trains of 10 to 12 capsules. This would give 1 second spacing between trains, and permit deceleration of 20 g, which is tolerable. The first train up-track from the one experiencing trouble would have 1 second to slow, the second train 2 seconds and so on. This would form a time cushion against pile-ups.
To get additional safety, traffic could be lowered and/or the proportion of freight increased.
Having had a good perusal of these speculative tube systems, I think I'll return for now to kicking the tires of regular EVs.
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Post by huon on Sept 12, 2013 14:04:47 GMT 9.5
There is a positive feedback loop between clean energy tech and clean energy policy. The more clean tech, such as electric vehicles, people buy, the more support will grow for a CO2 price. (If one has an EV, who cares what gasoline costs?)
Expecting--and eventually getting-- higher fossil fuel prices, people will then buy even more clean tech. Every Tesla, BMW i3 and Nissan Leaf that rolls off the assembly line aids this virtuous cycle.
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Post by edireland on Sept 12, 2013 16:35:51 GMT 9.5
Even 20g is far too high for braking performance. That would require everyone to be restrained in a multi point harness and orientated to counteract sudden g-forces that could come from nowhere. It would mean any time would be absolutely lost since you would not be able to move a muscle. 1g at most.
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Post by huon on Sept 16, 2013 11:16:37 GMT 9.5
The ET3 tube transportation system, www.et3.com , might be safest with the seats facing to the rear. According to the Wikipedia article on g-force, section 3.2: "Early experiments showed that untrained humans were able to tolerate a range of accelerations depending on the time of exposure. This ranged from as much as 20 g for less than 10 seconds, to 10 g for one minute...." en.wikipedia.org/wiki/G-force . The capsules would be automatically controlled, so any brief immobility of passengers would not be a problem.
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