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NYC Subways Testing Flywheels
socolow writes "The New York Times (free registration required) has an article about the NYC subway system's use of flywheels to store the braking energy of trains approaching stations. Not only does this advance the development of flywheel energy storage, but it will help relieve a lot of the heat subways generate (always appreciated during the summer)."
While a worthy idea, there are simply to many frail/handicapped/uncoordinated people who would make a system like this a nightmare...
BBK
Why not just use regenerative braking.
Aren't they already electric?
It is probaly easier to implement (mechanically) and less additional weight on the subway.
Now if they just make the flywheel out of a superconductor, then not only will it store energy, but the train will be weightless!!!
Boeing, get on it!
Don't Bogart the fish sticks
sPh
Since the flywheels are just great big gyroscopes, what happens when the train makes a sharp turn?
A legparnasom tele van angolnaval.
Wired ran an article about the new flywheels a while ago.
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Unfortunately, it takes 45 minutes of winding for 4-5 seconds of run time.
Before the visit ended the other day, a final question had to be asked: What is the purpose of the floating ping-pong ball?
"Oh that?" Mr. Lobenstein smiled like a child. "That's just to amuse us. Sometimes we get bored."
I believe thats what they are doing, except they are using flywheel batteries to store the electricity generated during braking.
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I still think my hamster could spin a wheel faster than some dumb fly.
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regenerative braking, not sure what technologies are used by it.
they'd still have to slow to a crawl, unless you want to jump off a train going 35 mph...
Hmmm the heat has little to do with the electric motors, and much more to do with Air Conditioned Subway cars. The heat in the cars has to go somewhere so it (and some energy involved in moving it) goes out into the tunnels and the stations. Suposedly before A/C the cars were hot but the stations were cool(as one would expect for what is bassicaly a basement.)
I'd do something interesting, but my server can't handle a slashdotting.
I wouldn't mind that myself.
I wonder how much the NYT pays Michael to post their articles links here. I swear almost every article he posts is from the NYT page.
--Won't that be grand? Computers and the programs will start thinking and the people will stop. - Dr. Walter Gibbs
The modifications to the trains are actually significant to support this, but it's about how the braking systems work and how the motor controllers work on the trains. There are a class of motor controllers that are not really compatible with regenerative braking, and they are fairly commonly used since they are cheaper than the others. The conversion to regenerative braking may involve replacing a fair bit of gear on the rolling stock. They were considering this kind of thing in San Diego, which is where I picked up lots of this trivia.
Many rail systems and streetcar systems have regenerative braking, but frequently they don't store the energy. What they do is have one unit braking while another is accellerating, so the excess power is in effect transferred via the wire to the other vehicle. Think of cable car systems where the guy at the top of the hill counterbalances the one at the bottom. This is hard to make work though, the timing issues being what they are.
My $.02
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From the out_of_the_topic dept.
If you dont wanna register at NYTimes visit NYT Random Login Generator
But because NYTimes block based on referrers you got two chances 1 - Disable Javascript or a better one get Multizilla Toolbar for Mozilla
It has a nice option like "Dont send referrer" .
Choose it and boom you are in !
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Or, as Robert Schmitt, another transit electrical official, put it, excitedly: "They're sitting here, saying: `Give it to me! Give it to me! Give it to me!'
Ok, this guy needs to get laid. Now.
Where does the school board find them and why do they keep sending them to ME?
Now, if they could just do something about the smell. The Broadway-Fulton-Nassau station certainly gets rank in the summer.
Save the planet. Vote NO on flywheels.
-- Thou hast strayed far from the path of the Avatar.
and a million watts is a lot of power.
Let's hope those flywheels are enclosed in something pretty solid.
Storing that much energy is one thing. Accidentally releasing it is another. When I was a student at MIT there was a permanent display in a glass case in the hallway of the biology department showing a centrifuge rotor that exploded, just to remind everyone of what happens when something spins too fast.
Let's also hope there's something to muffle that 600 Hz whine (which is close to the peak of human hearing sensitivity).
And I thought the wheels on Boston's Green Line screeching when going around sharp turns was bad...
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Related to this is the Parry People Mover which has been developed by a small company in Wales. This is designed as a light urban tansit system using flywheel to run the "people movers". The flywheels in these lightweight cars are recharged by either onboard LPG internal combustion engines or by electric motors fed from recharging points at stations.
They have been trialed on the Welsh Highland Railway and on the island of Mauritius omngst several other schemes - a quick Google search will turn up a lot more information about some of the trials.
While not a total success it is good to see innovation in this area.
Sailing over the event horizon
Right here A very good article (with illustrations) that tells how flywheels work and store energy. Pretty neat stuff.
What about the homeless people who rely on the subway heat vents in the winter?
thelocust[dot]org
I personally love the idea of using flywheels to store energy in this manner -- it seems very elegant to simply transfer the energy into rotational motion, rather than simply losing it all as heat.
There's one safety concern I have that I haven't yet seen addressed, though I've probably just missed it. If a flywheel is spinning at several tens of thousands of RPM (such as the 36,000 RPM flywheel mentioned in the story), what happens if the flywheel's physical supports are damaged or destroyed?
Basically, let's say a truck crashes into the building storing a spinning flywheel. The flywheel's housing is hit and breaks, putting the flywheel into physical contact with other materials. What happens? I have visions of a thousand-kilo ceramic disc either spinning off like the Tazmanian Devil, leaving a disc-shaped cartoon hole in whatever it encounters, or shattering upon impact and spraying shards of material at hundreds of meters per second in sundry directions.
The problem is, I don't know if this is actually true or not. Can anyone with an actual knowledge of such things answer? Thanks.
"Destroy science and religion. Science would re-emerge exactly the same; but not religion." - Penn Jillette, paraphrased
Of course, I don't recommend loop the loops, and the CrossRoads of Danger(TM) would have to go.
The cool cardboard desert backgrounds and grandstands could stay, though. And the orange plastic track would make an excellent subway defense weapon!
"Mom, he's beating me with the track again!" "Well, hit him back, I'm busy!"
sPh
A good break down of Power vs. Energy located here . Not here.
If we don't fight for ourselves no one will.
I love the NYC Subway system. It smells bad at times, but its an engineering marvel. So many people, tunnels, electrical, mechanical systems. a good website is http://www.nycsubway.org
http://github.com/gbook/nidb
Yes, and what do you do when you get to the end of the moving sidewalk; get thrown off the platform at 20 MPH?
That what was all this school was for... to teach us how to solve our own problems. -- janeowit
Effectively this is like a big capacitor. I surmise a chemical battery would have issues with constant discharge/recharge. Whereas a flywheel couldn't care less.
:D
The flywheels could not go in the train because the bumpy ride would continuously siphon off power, and you know power siphoned off would be in the form of heat. Not to mention that each battery weighs as a small volkswagen
Their solution to the voltage loss in the 3rd rail is a half-assed one. They claim the distance between the trains would cause too much loss in the line if they tried to transmit power back across it. Yet they are still transmiting power across it anyway?!? They must plan on the average distange between a train and the battery station to be smaller than between a train and another train, though the article strangely failed to say.
I really didnt enjoy 1/2 the article being fluff about the lack of glory in being a transit engineer...
It's been done.
They'll put your eye out.
I understand the concept of harvesting braking to push a flywheel to greater speeds, therefore storing the energy, but I have a couple of questions:
Aren't flywheels tremendously heavy? Wouldn't the additional weight cause longer stopping distances, especially under emergency braking?
I do understand that the braking would be assisted by the flywheel itself (spinning it up), but you never get anything for free (See The First Law of Thermodynamics.). When spinning up the wheels, you'd have heat loss, and loss again when they are spun down. Secondly, again, because of the 1st Law, wouldn't the heat generated by all of those flywheels spinning up and down exactly equal the heat savings? Moreover, thinking of emergency braking - What is the top speed of the flywheels? How strong do the gears need to be to spin up the flywheel to top speed very quickly? And at what tremendous gear ratio?
Don't think that I'm against it, cause I'm not. I think the electricity savings alone make it worth the effort and expense, but I'm not convinced that the trains would be as safe as the existing ones, and that there would be any heat savings. That said, CA needs to convert the BART next....
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The article says that the chief electricians were able to get a ping-pong ball to levitate!
Has anyone told Boeing yet?
A: None. The Universe spins the bulb, and the Zen master merely stays out of the way.
Try to do people a favor and this is the thanks one gets around here. ;)
...to the conservation bomb.
Flywheel UPS information is here.
If we don't fight for ourselves no one will.
Both require some physical agility, and are rarely seen today.
I think he's saying NYT, because NYT is the registration required website which has the highest likelyhood of being on /.?
http://web.mit.edu/charliew/www/centrifuge.html
How about we all simply agree that we all know that NYT requires registration, and stop putting "free registration, blah blah blah" in all the damned stories!
Sorry. Too much caffeine today.
Most of the warmth in the subways is caused by heat that has been absorbed by the roadbeds above radiating downward into the stations, to a lesser degree by the exhaust of the air conditioning on subway cars, and to a still smaller degree by steam tunnels that border some of the tunnels and run in parallel conduits. Not by braking trains.
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Heinlein's "The Roads Must Roll" (1940) predates Clarke's Against the Fall of Night (1953). You can read the Heinlein tale in The Past Through Tomorrow. It tells the story of what happens when the blue-collar workers who run and maintain the moving-sidewalk "roads" go on strike. (Hint: Mayhem.)
That would assume that a flywheel would be a better battery than fuel cells. At the power output level that you need for a UPS, the answer is probably no.
Well, maybe the next time the cops offer them a spot at the shelter, they won't turn it down. Police and social services go out every night and round up the homeless so they don't freeze to death. Some of the homeless prefer a subway grate to the shelters and if they're not obviously nuts, the police have to let them do it. 1/3 of the homeless population is mentally ill.
It's illegal to be homeless in New York City.
Don't believe me? Want to mod me down? Go ahead, just don't try to not have a job or a home or any money in NY, otherwise they'll throw you in jail.
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A very, very big battery. Or, to be more accurate, 10 of them, each weighing as much as a Volkswagen Bug and together able to store up to a million watts of power.
Are we to take this article seriously, or to believe anything it says? If they do not know the difference between power and energy, there is no telling what else in the article may be untrue.
Oh well, guess I deserve to be considered troll then. :)
Each flywheel gave steady 25 horespower and could double that for short kicks. Four would drive a car, but you could fit about 16 in an engine compartment (don't need engine, transmission, etc). That's 400 horsepower, and if you floor it you get 800 instantly! Also they would take you about 300 miles on a spin-up, which was accomplished by plugging the car into a wall socket, revving up the wheels with an electric motor - a charge would cost about 6 dollars of electricity.
Flywheels are better than batteries in a lot of ways. I'm glad to see they are finally being used for commercial applications. I haven't heard anything about the automobile flywheel guy since, but I'm sure his work won't be for nought. I'm equally sure car manufacturers and oil companies would stop him flat if he tried to market it though.
http://www.discover.com/search/index.html
You can search for it here with 'flywheel' as keyword - article name is 'Reinventing the Wheel'.
Stop the Slashdot Effect! Don't read the articles!
any /. story where the bulk of the information is on a NYT-hosted page is useless to me
Why can't you just post without reading the articles - like everyone else?
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Yes, and what do you do when you get to the end of the moving sidewalk; get thrown off the platform at 20 MPH?
I dunno, lay down some foam or somthing.
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Yeah, 'cause here in Califronia we're all huddled in the dark trying to cook food with power from the rationed 9-volt batteries that FEMA hands out once a month.
I saw this figure mentioned in the boeing article as well. I don't understand where it comes from.
If an object sitting on the ground were to no longer feel the earth's gravitational pull, I don't think that it will fly up into the air. At first, it would just hover up against the ground. It would continue moving at ~1050mph (the tangential velocity of an object on the earth's surface) in the direction it was moving when the gravity stoped. It's like if you were to stand on the edge of a fast moving merry-go-round, and slip off. In the first few instants, you would have almost no speed relative to the ride, but you would continue going the same speed that you were before, in the same direction. If you were to continue flying away for some time, the greatest speed relative to the center of the ride would be the origional tangential speed. In the case of the earth, that's ~1050 mph.
Don't Bogart the fish sticks
I was thinking about this the other day, when signing up for some similar site: I thought the WTC used to have their own ZIP code(s). I was too lazy to look them up to use them, but I wonder if they would have worked.
Out of morbid couriosity, has anybody researched using fast flywheels as weapons?
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I seem to recall reading many years ago about testing on a bus that had a flywheel for regenerative breaking (in Scandinavia IIRC). The main problem with it was the gyroscope effect - trying to turn left or right creates a force at ninety degrees (ie up or down) and this proved too much for the suspension to deal with. Guess it's less of an issue with a subway train...?
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Yes, and what do you do when you get to the end of the moving sidewalk; get thrown off the platform at 20 MPH?
Move onto a 15mph one
Amusingly enough, there is a subway in Cincinnati. Well, about three or four stations worth, anyway. They started construction on it in the 70s, ran out of money, and never completed it.
More details here.
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so they have to figure out a way to close off the stations ventilation during the winter. there is not going back :)
I think people all over the country are being hit with blackouts due to the unseasonably hot and humid weather. Here in SE Michigan we have been routinely having 90%+ humidity levels on 90+ F days. People run their A/Cs non-stop and power consumption is extremely high overall. So far I think we have run into 10 or more blackouts over the last 2 to 3 months. I sweat like a fking pig out in the weather during the day (classes , plus I install and service A/Cs heh) so I crank my A/C down to 65 or 70 during the day depending on how I feel, and 65 or below during the night. Feels like winter when I wake up, but damn I sleep good!
They use DC for the same reasons that elevators use DC..smooth braking and acceleration.... Also, DC is necessary because as part of the power distribution there are 'breaks' in the third rail...and the rail actually uses the car to complete the break. An AC system would have to maintain phase scycronization for this to work.
Carbon fibers, but that will change with nanotubes within 10 years.
Berto
What about the homeless people who rely on the subway heat vents in the winter?
They actually hang out near the steam vents so it's not really a problem. I live near a co-generation plant so there are a few extra citizens on cold winter days around here.
... and I'm thinking about all these drunk people never going home, and some Guinness world records being set for party length and alcohol consumption.
They need to have this.
I'm not sure which of the noises you are talking about but I agree with you!
It's kinda like a forced upgrade
The new trains like those that operate on the 6 line actually drown out a lot of the track noise and have less jumpy/noisy ractions to track imperfections, right? However, whatever it is, their new turbine-like humming is very noisy, though it sounds more like something between 440+ and 512- Hz (near the key of B). The train ride is more comfortable, but I have found it hard to talk to girls because the noise drowns out their voices. The loud whine starts up as soon as the train accelerates and I have not heard it inside or outside the older trains (A, B and D, older 4 models, etc)
I hope someone notices the whine before the state spends millions replacing the trains that didn't have that 'feature.'
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