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Post by edireland on Sept 16, 2013 18:28:07 GMT 9.5
Yes, but even at 700mph it is going to take a while to get several hundred miles (which is presumably the sort of journey length we are going for?). Passengers probably won't like not being able to move a muscle. (Since if they have they are holding say a 500mL bottle of coke in front of them when the acceleration commences it will become a ten kilogramme projectile dropping onto their chest, and that is before we include the arm holding them).
Laptops become 20kg weights smashing into your chest.
Its a nightmare.
And remember unless we want all the capsules to do exactly the same journey we need some pointwork to change routes. This pointwork has to confirm that the previous vehicle has cleared the junction, then it has to set the new route required by the next vehicle, and then it has to gain interlock to confirm the new route has been set. It has to have interlock prior to the next vehicle being unable to stop before the junction or you risk a vehicle slamming into a half set junction mechanism.
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Post by huon on Sept 17, 2013 11:12:38 GMT 9.5
Well, edireland, you are quite right that there are dangers associated with ET3 tube transport. Whether they are acceptable, I don't know. On the other hand, switching is not quite as you envision it. The track simply bifurcates, and the capsules automatically "switch" themselves, at speed, like a car at an exit.
Anyway, I've said my piece about tubes. So next I'll post about a less speculative vehicle.
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Post by huon on Sept 18, 2013 8:50:23 GMT 9.5
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Post by edireland on Sept 18, 2013 8:56:58 GMT 9.5
Flash charging buses is problematic if done on a large scale IMO thanks to grid stability issues.
I am much more of a fan of trolleybuses.
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Post by Roger Clifton on Sept 18, 2013 13:39:54 GMT 9.5
Buses are going electric, too. Here's one example of a bus that can be "flash-charged" The top-up-at-a-bus-stop scheme in Huon's link may actually be kinder to the grid than the trolley bus equivalent. At specially equipped bus stops, a supercapacitor of maybe 3 kWh is charged up over an interval shorter than the interval between bus arrivals. When the bus stops as normal, 6 MJ is dumped into its battery. Then, off it goes moving people until it gets to the next equipped bus stop to be topped up again. If the (re)charging time for the supercapacitor is 1000 seconds, the charging rate would only be 6 kW. If the charging time were programmable to be almost as long as the interval between this and the next bus, the load on the grid would be nearly continuous, unlike trolley buses that repeatedly stop then accelerate away. With less energy on board at any time, the bus presents less of a risk during an accident. Check out his link...
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Post by edireland on Sept 18, 2013 19:16:46 GMT 9.5
It may be less risk during an accident, but cutting down the amount of energy in the pack represents a risk of the bus becoming stranded in heavy traffic.
Especially, if for example, it has been fitted with air con (which is going to be increasingly expected on all buses I think in the future) and is stuck in traffic.
The auxiliaries could easily run the supercapacitor pack down requiring far larger packs than actually required to traverse the distance in ideal conditions, (and route diversions will require significant energy storage capacity that will have to be provided either by batteries or an auxiliary generator).
And I live next to a bus route where, for most of the day, the time between bus arrivals is closer to 10 seconds than a 1000. (Over sixty buses per hour for most of the day)
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Post by Ed Leaver on Sept 22, 2013 16:45:47 GMT 9.5
I tend to agree with edireland. If trolley-bus acceleration load surge were a problem (and it it isn't), one could as easily just connect a capacitor (or battery) directly across the power lines and be done with it. But I'm thinking modern trolley buses might incorporate a small on-board battery as well, against the likelihood some clown blocks their route to the point they have to detach from their power line in order to detour. Wouldn't need much -- just a few hundred meter range. But the battery bay might be made large enough that a bigger unit could be slotted in in an emergency, extensive road repairs, etc.
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Post by huon on Oct 1, 2013 12:08:48 GMT 9.5
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Post by Ed Leaver on Oct 2, 2013 9:06:16 GMT 9.5
Cool kit, huon. Thanks for the link. I still see proposals for street-sited rail trolleys in urban areas (Denver, Salt Lake City). I have to assume their proponents are just not familiar with trolley-buses. Cheaper, faster, and much more flexible. Rail is fine, provided one has dedicated right-of-way. Rail trolleys and motor cars have never well mixed.
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Post by edireland on Oct 2, 2013 11:03:53 GMT 9.5
Cool kit, huon. Thanks for the link. I still see proposals for street-sited rail trolleys in urban areas (Denver, Salt Lake City). I have to assume their proponents are just not familiar with trolley-buses. Cheaper, faster, and much more flexible. Rail is fine, provided one has dedicated right-of-way. Rail trolleys and motor cars have never well mixed. Indeed, you tend to end up with things like this (from the last few boat trains to serve the Weymouth Harbour port in the 80s):
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Post by huon on Oct 2, 2013 16:10:50 GMT 9.5
Thanks, Ed Leaver, for your deft summary of the advantages of trolleybuses.
And I had a very good laugh, edireland, watching the video. Rapid transit at its finest.
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peterc
Thermal Neutron
Posts: 30
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Post by peterc on Oct 3, 2013 2:12:23 GMT 9.5
..ah, trolley buses : I still remember Bournemouth's all those years ago (giving o'self away). One of the disadvantages is having all those overhead lines, which are just a little bit disfiguring for the city landscape.
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Post by huon on Oct 3, 2013 13:23:21 GMT 9.5
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Post by huon on Oct 7, 2013 13:59:17 GMT 9.5
In the race of solar cars through the Outback, the Dutch teams are particularly strong. Stanford and Michigan from the US are not too far back. And a couple of Australian teams are doing well, especially "eVe" from the University of New South Wales in the Cruiser Class. www.worldsolarchallenge.org/dashboard/mapIronically, in a few days, the cars will pass within 100 km of the Olympic Dam uranium mine, which could power millions of electric cars.
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Post by huon on Oct 10, 2013 11:47:05 GMT 9.5
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Post by huon on Nov 11, 2013 16:57:46 GMT 9.5
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Post by huon on Jan 31, 2014 16:51:56 GMT 9.5
Recently, a Tesla drove across the US using Superchargers, Nissan sold its 100,000th Leaf, and demand for the BMW i3 has appeared strong. These developments give fresh support to an article entitled, "Have Electric Cars Already Reached the Tipping Point? ABB Says Yes." "ABB bases that on the ever-declining cost of batteries, which it states is dropping by 20-30 percent per year. "The increasing affordability of batteries is one of the main drivers of cost-effective electric vehicles, and once EVs become cost effective--and price eventually reaches parity with internal combustion vehicles--that's when sales should really take off. "ABB quotes a comment by Volkswagen that predicts electric vehicles would be cheaper to make than internal combustion ones in just three years." www.greencarreports.com/news/1089310_have-electric-cars-already-reached-the-tipping-point-abb-says-yes
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Post by huon on Feb 25, 2014 16:28:00 GMT 9.5
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Post by Scott on Feb 28, 2014 17:47:37 GMT 9.5
I really like the idea of these buses. Overhead wires can be eliminated. Buses will no longer be confined to the tracks of those overhead wires. Of course, much of the cost will be transferred maintaining the vehicle powertrain and charging stations. Wonder how economical it is?
From the source:
" To not disturb the electricity network, the flash stations are connected to the 50 kVA and power is provided by 3 kWh supercaps."
Charging 3 kWh supercaps with 50 kW is probably more easily managed than a trolley bus power system.
Unlike internal combustion engines, electric powertrains consume precisely zero power when stopped (minus negligible amounts of power for the inverter controller, gate drive circuitry). Aggressive regenerative braking can also be implemented which can recapture some of the energy used when accelerating.
For the Nissan Leaf:
In heavy stop-and-go traffic, averaging just 6 mph with temps of 86 degrees and A/C on, range drops to 47 miles.
At 55 mph on the highway in 95 degree temps and A/C on, expect range to be 70 miles.
It is merely something which needs to be managed properly by having a somewhat larger battery or capacitor bank than otherwise.
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Post by Scott on Feb 28, 2014 18:31:36 GMT 9.5
Also regarding electric cars: green.autoblog.com/2013/05/08/next-gen-chevy-volt-could-be-10-000-cheaper/www.nytimes.com/2014/02/27/automobiles/tesla-plans-5-billion-battery-factory-for-mass-market-electric-car.htmlTesla GigafactoryThe excitement about the EV isn't that they are overall better than the internal combustion engine (ICE) vehicle at the moment. Generally, they are not. But it is the direction they are heading in. 15 years ago the GM EV1 had a ~500 kg battery pack that had 25-30 kWh of energy. ~1100 were built. Today we have the Model S. 600 kg battery and 85 kWH of energy. It's really the first EV that is overall better than an equivalent ICE vehicle, not despite being an EV but because it's an EV. Tesla want to make about 40,000 of them this year. Now there is talk of Tesla making a $35,000 sedan with > 300 km range and super charging. And a battery factory that can produce enough battery packs for 500,000 of them, per year, reducing battery costs by over 30% after the first year of production around 2020. They will also likely sell the batteries to other manufacturers for lower end vehicles.
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Post by huon on Mar 12, 2014 7:23:39 GMT 9.5
Good comments, Scott. We are currently in the middle of a clean-energy revolution, in which plug-in vehicles will play a large part. It's going to be a fun ride.
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Post by Roger Clifton on Mar 16, 2014 17:26:05 GMT 9.5
Slow vehicles tend to be energy-efficient. Roads used to be divided into a "fast lane" and a "slow lane". The slow lane was once dominated by horse-drawn vehicles.
In a more graceful future the slow lane might return to be dominated by non-highway electric vehicles – such as local runabouts, powered bicycles, tricycles, delivery vans, the mailman, the milk float, electric wheelchairs and of course, Segways.
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Post by huon on Mar 26, 2014 15:42:26 GMT 9.5
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Post by Roger Clifton on Mar 26, 2014 18:47:13 GMT 9.5
Slow short-distance vehicles in dedicated slow lanes, would provide something of an answer to the problem of accessing public transport from the suburban sprawl. "Park'N Ride" systems are ready made for them.
Huon, your vision of electric skateboards goes one better by providing a vehicle at the far end of one's journey on the public transport.
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Post by huon on Apr 7, 2014 16:51:32 GMT 9.5
Incidentally, an electric skateboard plus a carbon-fiber helmet is a pretty good representation, in miniature, of a BMW i3. "[The i3] is the first production application of a construction concept that's been kicking around for more than a decade, the so-called *skateboard platform*, in which the chassis is one self-contained unit and the passenger cell is another.... "BMW calls its skateboard the Drive Module, and fashions it almost entirely from aluminum.... Atop the Drive module sits the Life module, which is crafted primarily from carbon fiber." www.caranddriver.com/reviews/2014-bmw-i3-first-drive-review
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Post by Scott on Apr 11, 2014 22:06:06 GMT 9.5
Plenty of existing vehicles essentially use a "skateboard platform". Tesla Model S & Mercedes SLS AMG Electric Drive come to mind. Not sure if the Chevy Volt uses something similar. Electric Vehicles also offer a much wider set of packing options than ICE cars - one idea is a hub motor inside each wheel, unsprung, controlled independently depending on the conditions of the vehicle at any time (torque vectoring). Obviously this increases the number of sensors and power electronics required, but it's an interesting idea.
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Post by huon on May 2, 2014 15:55:32 GMT 9.5
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Post by huon on May 4, 2014 15:57:58 GMT 9.5
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Post by huon on May 16, 2014 16:36:48 GMT 9.5
This new battery, which uses carbon for both anode and cathode, looks promising: "Power Japan Plus says that its battery charges 20 time faster than lithium ion batteries; is rated for more than 3.000 cycles; and can slot directly into existing manufacturing processes, requiring no change to existing manufacturing lines." www.greencarcongress.com/2014/05/20140514-ryden.htmlOf course, we'll have to see whether it can deliver on those figures.
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Post by huon on May 16, 2014 16:37:47 GMT 9.5
This new battery, which uses carbon for both the anode and cathode, looks promising: "Power Japan Plus says that its battery charges 20 time faster than lithium ion batteries; is rated for more than 3.000 cycles; and can slot directly into existing manufacturing processes, requiring no change to existing manufacturing lines." www.greencarcongress.com/2014/05/20140514-ryden.htmlOf course, we'll have to see whether it can deliver on those figures. (Sorry, Moderator. The Forum host was having a few problems as I tried to post this. Please delete the extra copies, or leave them, as you wish.)
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