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Battery Powered Tram Charges in 60 Seconds
Posted by
ScuttleMonkey
on Mon Oct 29, 2007 05:08 PM
from the streetcar-named-yokubou dept.
from the streetcar-named-yokubou dept.
SK writes to tell us that a new streetcar, powered by lithium battery, has been invented by the Railway Technical Research Institute in Kokubunji, Tokyo. The new transport is capable of speeds of 40 kph for 15 kilometers and can convert 70 percent of its deceleration energy into electricity which is then sent back to the battery which can recharge in under one minute.
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What's Wrong With Lithium Ion Batteries? 289 comments
An anonymous Coward writes "Lithium ion batteries short-circuit. They overheat. They burst into flames. The reasons behind the recent spate of problems with a technology invented by Sony more than a decade ago are complex and varied, making for one big engineering headache."
Submission: Tram runs on Lithium battery & charges in 60 s by Anonymous Coward
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Correct me if I'm wrong... (Score:5, Insightful)
Isn't this just solving a problem which doesn't really exist?
Re:Correct me if I'm wrong... (Score:5, Interesting)
Parent
Re: (Score:2, Interesting)
See, that's the problem with current thinking re the carbon problem. We're just throwing more technology at the problem, technology which is subsidized entirely by the present fossil fuel economy. The only real long term solution to the carbon footprint problem is to radically re-think how we live our lives. Do we need to travel to and from work everyday
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Of course it is quite clear he meant $1 billion per year in terms of the cost of electricity had it been produced by a power plant (which includes fuel, construction costs, transmission losses and so on).
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But until then, throwing money and technology by taxing carbon is probably the best way of dealing with CO2. CO2 is a waste and when consumers pay for the waste they generate (ie. business ge
Re:Correct me if I'm wrong... (Score:4, Funny)
Parent
Trams are the wrong solution (Score:5, Insightful)
Trams in particular have very short distances between stations, often only 500m or so. Great for getting on and off, it makes them very accessible unlike traditional rail which doesn't get used much because the stations are so far apart, but, because the distance is so short, they literally spend all of their time accelerating, decelerating and stopped.
Now, the most efficient way to run a vehicle is at a constant speed, acceleration is expensive in terms of energy, and the more mass you have, the more energy you expend. Trams almost never reach a constant speed and because they're basically rail, they're extremely heavy as well.
Essentially trams are a square peg beaten into a round hole. Hence the battery kludge to try to make them more efficient.
Parent
Re: (Score:3, Interesting)
Rail doesn't necessarily mean heavy. And trams are usually powered by low-voltage DC (relatively low: 600V as opposed to up to 25kV for a lot of trains) overhead lines, which makes pumping energy from regenerative braking back i
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But hey, that's the exact thing that this article is about! If this battery solution eliminates most (70%) of this overhead, then maybe it's not a completely different story anymore?
Re:Trams are the wrong solution (Score:5, Informative)
Currently being implemented by BAA at Heathrow Airport... The busiest international airport in the world.
http://www.telegraph.co.uk/news/main.jhtml?xml=/news/2005/10/20/npods20.xml [telegraph.co.uk]
HTH.
Parent
Always was this way. Batteries not included. (Score:5, Informative)
And it already works that way. And it has been working this way since brush-powered electric trains and buses were first built.
If you've got a speed-controllable electric motor hooked to an electric grid, you can do regenerative braking by setting the motor's desired speed to something lower than its current speed. The motor then DEcelerates the vehicle, acting as a generator and putting the vehicle's energy (less resistive, eddy-current, hysteresis, and excitation losses) back into the power supply.
If there are rotary converters (or suitably designed electronic converters) in the system (for instance: To turn line AC into DC or lower-frequency AC for the trains/buses), they do the same thing - pushing the energy back toward the main grid. If not, the energy is still usable by other vehicles on the system that happen to be consuming power, dropping the amount that needs to be pulled from the primary supply.
This is very convenient: In addition to the energy savings, the vehicle's mechanical brakes get much less use, and much less wear. They can be reserved for the last moments of a full stop, holding the vehicle motionless when stopped, and for emergencies. This drastically reduces the necessary maintenance.
What the super-fast-charge battery does is let you do the same thing - MAJOR regenerative braking - for a vehicle that's NOT continuously attached to a power grid. The current hybrids do some of this using more ordinary battery technology. But there are limits due to the batteries' slow charging, large losses, and weight. The fast charge means even a panic stop can be salvaged and a much lower weight of batteries is necessary for a given RATE of energy transfer.
Also: The fast charge implies that the batteries lose very little energy when storing it (otherwise they'd melt down or catch fire). This implies low internal resistance, which also means fast and efficient DIScharge when you want the energy back. So we finally have batteries that can perform as well as (or better than) a (still mostly impractical) flywheel/motor-generator system for "peaking" storage. (TFA's stated losses of about 30% per stop/start cycle look about right for a system where the losses are virtually all in the motor and controller. That would be about 84% efficiency on both start and stop cycles, which is right in the ballpark for a good motor.)
Size the batteries large enough to store the power of a vehicle coming down off about 8,500 feet of mountain freeway and making a full stop near sea level and you achieve the full potential of regenerative breaking: The engine then needs only to be big enough to fight friction - like under 20 horse - and can run at maximum efficiency when it runs at all. Size them maybe a tad larger to also run a couple long and hilly commute-and-shopping cycles on a line-powered charge without starting the engine - reserving the engine for long trips - and you also achieve a fully-functional "plug-in hybrid", a single vehicle adequate to completely replace a normal, non-hybrid, car in ALL service cycles and run off utility electricity (currently the equivalent of about $0.75/gallon gas) in all but cross-country trips.
The usual statement about such breakthroughs - that deployment is always 10 years away - seems to have been hurdled. This technology was at that stage a year or two back. But THIS announcement, of deployment in a vehicle (even though experimental) implies it's not just sitting in the lab, but getting some real-world production and testing. Once that's a production vehicle (if not sooner) the batteries will also be available to automobile designers...
Parent
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I suppose a bus that works in the same fashion could be even more beneficial since it would combine the route flexibility of a bus with the cheapness and cleanness of an electrically-powered vehicle
Best reply of the bunch (Score:3, Insightful)
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PS: The self-recharging tram is not in charge of Gundam.
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But a tram runs on rails which mean it always follows a known route rather precisely and can therefore be supplied with electricity directly... No batteries required.
Currently, many tram systems (for example, Melbourne, Berlin) do generate electricity when braking, giving back electricity to the tram network and helping to save some energy, if another tram happens to be accelerating or running at the time.
However, if a tram is on a regional route and far from any other trams, such as at a late hour, this energy is wasted.
Using flywheels and other mechanical devices has been tried but is dangerous and expensive.
This battery device would greatly increase the efficien
Sweet!! (Score:2, Funny)
A street car that runs on Sapporo! Can you drink out of the tank! Oooo sushi bar in the back of the car, drink out of the tank, party train!
Wait, it's 'in' not 'on'?!?
Dammit! I just bought plane tickets. Shit.
Obviously... (Score:5, Funny)
How much charge? (Score:4, Interesting)
It seems we now have the ideal battery (also called a "capacitor"), now let's concentrate on creating the superconducting cables and contacts.
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How good is this ? (Score:2)
According to the institute, it uses about 10 percent less power than existing streetcars.
Apparently, not very. Consider the initial cost of the battery (li-ion is not cheap, the tesla roadster [wikipedia.org] for example costs $100,000 most of which is for the battery pack, ~ $75,000 IIRC). Then consider the cost of disposing or recycling the batteries which will presumably need to be done several times in the life of the streetcar. I guess this is a start, but at 10% less power, I don't see this as much of an advantage.
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Some disadvantages which it seems no amount of modern tech could get around are (from the article):
* Weight, a bus which can carry 20 persons and has radius of 20 km, must carry a flywheel which weighs 3 t.
* The flywheel, which turns at 3000 revolutions per minute, requires special attachment and security--because the external speed of the disk is 900 km/h.
* Driving a gyrobus has the added complexity that
Streetcar (Score:5, Funny)
OMG so they could be (Score:2)
Do those batteries have a maximum charging rate? (Score:2, Insightful)
Old idea just new technology (Score:2)
What makes this new is improvements in motor control circuitry making regeneration a lot more practical for streetcar use and improvements in battery technology - the old battery cars typically used Edison cells.
Charge a lithium battery in one minute? (Score:3, Funny)
hopefully this time they will stay around (Score:5, Interesting)
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Why am I always the last to find out about these things? First it's a club meeting here I somehow did not know about but everyone else did, then something else there, and finally now I hear that 9 World Wars happened when I wasn't looking. I know I occasionally miss things, but this is just too much!
And more importantly, who won them?
Awesome Lithium Tech (Score:4, Interesting)
I am not a big fan of lithium ion tech. It seems very gimmicky to me; allowing manufacturers to claim that their laptop batteries last N hours when in fact that will only be true for less than 6 months, as the charge capacity of lithium ion batteries always rapidly deteriorate.
My Panasonic Y2 battery started at 6+ hours per charge, and is now, after not even three years, down to about 2.5 hours per charge.
So if the streetcar in question uses similar tech, then I would expect its range to diminish rapidly with recharges. Since it will be recharged much more frequently than any laptop would, can we even expect its battery to last a whole year before becoming basically worthless?
Interesting application (Score:3, Interesting)
Visit Seattle and ride the SLUT [nwsource.com]!
A lot of questions about the why (Score:4, Informative)
Almost all trains are electrical nowadays, where they get their power from is the big question. Diesels get it from carrying a diesel generator with them. Handy because you can be totally disconnected from the net, disadvantage, extra weight (not that much of a problem in cargo trains where the locomotive needs all the weight it can get) and you are limited by the amount of fuel you can carry. Plus you smell bad.
The brits get their power from a third rail. Very hard wearing BUT you got a live wire exposed where everyone can touch it. Bad for level crossings, meaning the train needs facilities to be able to cross a spot without third rail.
Most other trains including light rail system like in the article and trolly busses, use an overhead wire (busses need two since they can't use the rails as the second wire). The problem with this is that it is fairly expensive, can easily break and gets in the way at level crossings where it puts a height restriction on traffic using the crossing.
There are ways around this, for instance at a bridge in holland by zaandam the overhead wire just has a missing part. Since trains typically only got one pentograph the train better be at speed or it will find itself without power (it is only a few meters and trains are notknown for their short stopping distances so this happening is highly unlikely).
This tram would allow itself to run off the overhead wires where they can be installed, but continue normal operation where they can't. This would make planning a lot easier because you can then keep roads open for special transports and still have tram system. This is extremely handy as lifting the wires everytime something big needs to pass is a hassle.
Finally why trams and not busses.
Several reasons, the simplest is driving license. Buss requires a bigger more expensive license then a tram/metro. This is important because while their not all that many jobs for a tram/metro driver, trucking has plenty of competition.
Trains offer a lot more space, because they can be build differently. A buss of the same weight as a tram simply can carry fewer people. While I have seen segmented busses with three segments now, that can carry a lot of people, they are still of lesser capacity then trams and have lost a lot of the freedom of movement of small busses.
Basically trams can move more people then busses can, on less real estate. The prime example might be in holland, between Leidseplein and Koningsplein, where trams run in both directions but the tracks "merge" in the street and split again on the bridges. If you know the area, imagine implementing the same amount of transportation with busses. YIKES!
Busses have their use, on infrequent routes, or routes that are too complex for a tramline. But when you have to move lots of people at street level, trams make a lot of sense.
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Re:Awesome (Score:5, Insightful)
- 40kph is enough. That's approximately 25mph, which is just right for light-rail.
- 15km is not quite enough. Many light-rail systems have stops that are farther apart than that. Double that number and it's golden. (15km = approx. 9 mi. 18 mi. should be enough for 90% of light-rail systems.)
Recharging at each stop is not unfeasible if the wait is only 60 seconds.
Now for the real problems:
- What does it cost?
- What does it cost to maintain?
If either of those numbers is large, it won't work in the US until mass transit catches on with the masses it's named after. Gasoline will have to be $10/gallon before that will happen.
Parent
Re:Awesome (Score:4, Insightful)
Add a second battery? That would double the range, and since you can charge them in parallel it should still only take 60 seconds.
Parent
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It does not require power at either track level or overhead. For new systems this is a cost saving (at least as far as the infrastructure goes). It also is safer.
It may allow systems to be installed where the were not previously feasible.
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No, but I meant for a car-car... just that piece of data didn't make it into the post. Improving street cars will do little to reduce pollution. What is needed is improvements that will allow for electric car-cars to become practical, and that was my meaning.
Re:Awesome (Score:5, Insightful)
However, I agree with some the arguments you make, if you view things from a purely American point of view. You describe an implementation and a system where public transportation has failed. However, one flawed implementation does not mean that the entire idea is bad.
Public transportation works in Europe. Granted, there are geographical differences as well as cultural differences. If you spent enough time in the right European cities, you would probably see systems where public transportation is working.
Here is one case study... I spent a year in Poznan, Poland (pop 567,882). In that city, there are 20 trams (streetcar) lines and 57 bus lines. The trams run center-city and through the more dense areas, with buses making up the difference. While some own vehicles, the public transportation system has high ridership, to the point that during rush-hour one must be careful not to be crushed... People are not living by loud trains, but they are more comfortable with walking and riding bikes, and there are sidewalks (something quite rare in the USA). It may be 1-2 kilometers to the nearest tram stop, and that is perfectly fine by the city inhabitants. In fact, I would drive to the mall a few kilometers away, I would get heckled by my wife's friends -- who would drive if it was only a 30 minute walk? That said, I lived right next to the tram on the 6th floor of a high-rise, and hardly noticed the tram. It wasn't much, if at all, worse than the traffic of an average suburban street in the USA.
The area in discussion is fairly low income, relative to the prices for gasoline and for automobiles themselves. While the salaries were magnitudes lower than those in the USA, gas prices were around $6/gallon. So, if gasoline was lower, or if salaries were higher, would public transportation falter? Perhaps slightly, but one must also remember that the streets in this particular city couldn't handle that much traffic. In fact, this is already a situation occurring in Poznan, as more become capable of affording the cost of an automobile. The streets are becoming crowded at rush hour, and many drivers are choosing to return to public transportation as it is simply a much faster method of travel. Why wait in a traffic jam, watching the tram go past?
In other cities I've visited where the cost of travel was not as much a concern, such as Germany, I found cities where public transportation was not popular, but on the other hand, good city planning had eliminated the need. Walking from one side of the city to the other was no more than an hour, and much less by bicycle. They simply built a number of smaller cities with great urban planning, and in the 20th century linked them with high speed light rail. Thus, if you would rather take a train for 40 minutes, rather than walking for 40 minutes, you could do that as well.
Either way, I'm not sure I've ever met anyone in Europe that spent more than 40 minutes getting to work. I only knew a small handful of people that used a car for work travel, and they were in sales, freelance photography, and real estate. All cases were they were constantly 'on the go' where a car made more sense. (and even then, they would often use public transportation)
In the US, the combination of suburban sprawl and law have created an environment where companies have pulled themselves out of the downtown environments. This amongst other practices has have undoubtedly lead to much success, raising profits, and has helped make us a rich nation. However, these are also the things that, if you want to bring freedom into this, have stripped us of freedom, such as the freedom to walk down the street without the fear of being run over -- something that Ray Bradbury certainly predicted with 451/451' vision.
Finally, my point isn't that you're wrong that there are challenges, I admit that there are. In the USA, city planning is simply not pedestrian and public-transportation friendly. To ch
Parent
Re:Awesome (Score:5, Insightful)
And this is the best part for you Libertarian slashdotters: we don't pay any taxes for it as it has been privatised for 8-9 years now. We used to subsedise it heavily but it has been self sustaining for the past couple of years and is actually turning a modest profit recently. Beat that!
And guess who is defending the public transport system here...a self proclaimed petrolhead. I have 3 cars and I absolutely love'em. A track-biased M3 beemer for my track days (soon to be replaced by an R8), a Megane R26 F1 hot hatch for my general use, and a super-hungry comfy V8 Holden (with the Corvette engine) for when I just want to enjoy the sound of that huge engine. But for me, cars are for Sunday mornings and track days and especial occassions, public transport is much more easier, cheaper and more comfortable for daily commute. If a public transportation system is built correctly, it can be so comfortable (short wait time, Air Condition in all trams, quiet and peaceful where I can read the newspaper or listen to my podcasts, never overcrowded) that you would loath having to take out your car and deal with the morning and afternoon traffic, just to get to work.
Get over your stereotypical notions of what a public transport system is and how it works. The world has moved on.
Parent
Re: (Score:3, Interesting)
In most of the US I'd agree, although not for the reasons the parent stated...public transit works amazingly well with older once-industrial cities, with a high-density downtown and either small clustered neighborhoods or high-density suburbs surrounding. It doesn't work well in a city which is essentially all "suburban." Not surprisingly, public transit does quite where you have the largest concentration of "old" cities. It works in places like san