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Superconducting Power Cable in Detroit

michael posted more than 13 years ago | from the cold-and-smooth dept.

Technology 144

mgarraha writes: "According to a Washington Post article, this summer Detroit Edison will lay 1200 feet of superconducting power cable near their Frisbie substation, which serves 14,000 customers in downtown Detroit. The cable, made by American Superconductor and Pirelli, consists of silver-clad HTS ceramic ribbons woven around a pipe for liquid nitrogen." We've mentioned this particular project before. It's not room-temperature, but still interesting to see superconductors coming into large-scale, common use.

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Re:interesting..but.. (1)

Anonymous Coward | more than 13 years ago | (#209174)

But you can't keep it pressurized. Like all refrigeration systems, it works by compressing the refrigerant into a liquid (where it will give off heat, like at the back of your fridge) then releasing it into a low pressure area (known as an evaporator) where it will evaportate. The process of evaporation requires heat, and it will take it from its surroundings, therefore leaving its surroundings cooler. That's how refrigeration works, so keeping it pressurized doesn't do anything until you allow it to depressurize and evaporate.

The nitrogen aint the problem (1)

Anonymous Coward | more than 13 years ago | (#209175)

The expensive part is the pipe and the buried tunnel. For superconductors to solve our most major electrical distribution problems, they'll have to run for thousands of miles.

Unfortunately, you're not going to see these brittle ceramic superconductors dangling in the wind from cheap steel towers. That means huge expenses incurred creating an entirely new underground long-distance power infrastructure. The real question is, will that expense be recovered?

> 20 years of widespread superconductor use (1)

Anonymous Coward | more than 13 years ago | (#209176)

Superconducting Niobium alloys (of the traditional Liquid Helium temp variety so as to avoid quenching in high fields) have been in use for more than 20 years now. Do you know of a major North American metro area that does not have an MRI imaging facility? No? That means superconductors have been in widespread use in routine clinical NMR-MRI imaging for all sorts of medical conditions (heart patients, epileptics and brain imaging, etc.). None of the liquid nitro temp ceramic compounds has the magnetic quench resistance that the niobium alloys do. A typical MRI coil needs to maintain a uniform field of 1.5 Tesla across the body parts being imaged - including whole body NMR scanners.

It'll last about an hour... (5)

Tony Shepps (333) | more than 13 years ago | (#209178)

Once those Detroit sorts find out there's Nitro in the streets, they'll be tearing 'em up for the liquid nitro-burnin funny cars! SATURDAY! SATURDAY! SATURDAY!

Koff-koff-koff OH man it's been a while.

Liquid Nitrogen is reasonably safe (2)

maggard (5579) | more than 13 years ago | (#209181)

As noted numerous times what we breath is ~75% Nitrogen (unless you live in LA, Denver or Dallas then check today's stats.) It's pretty much inert in the conditions most of us are familier with and would be so in the environment around a cooled-cable break.

Indeed if one had to dump something in the atmosphere this would be most folks #1 choice followed by pure water.

The biggest danger would be freezing something important like a bodypart from extended immersion. However since liquid Nitrogen behaves like most liguids and doesn't do anything funny it's not hard to understand/predict & it does evaporate easily.

Re:interesting..but.. (2)

maggard (5579) | more than 13 years ago | (#209182)

It is already extracted from the air, at roughly US$0.10/Liter which covers the cost of the equipment & handling plus some profit.

Liquid Nitrogen is used in LOTS of processes and has a well established production infrasructure. Indeed if you were to call a local distributer you'd find they likely deliver to most of the research, manufacturing & medical facilities around you; those they don't likely have on-site production.

If liquid-Nitrogen cooling cables takes off you'll likely see sales of modular production facilities increase but I doubt the overall economics will change: This is pretty basic & well established stuff.

Re:interesting..but.. (2)

KlomDark (6370) | more than 13 years ago | (#209183)

I was just at the Beckman Institute at the University of Illinois at Urbana/Champaign and got to play with this unsealed tank of lN2 - you just tipped it (It was on this hinged mount) and liquid nitrogen poured out of it. Great fun.

I poured it all over my hand, and hit it with a banana - my hand shattered into several pieces. Just had to hold them in place until they thawed and everything was as good as new!

(I am so full of shit. You ever call anyone a 'this'? It means 'mixed up piece of shit' - same letters, just mixed up. *snork*)

Re:Eliminate power outages?? (2)

KyleCordes (10679) | more than 13 years ago | (#209186)

Switching those wires to superconductors would take care of the loss due to resistance in the wires, but it would not prevent the inductive transfer of power to other conductors (like the "capture coil" and florescent light you mention).

hm.... (2)

elmegil (12001) | more than 13 years ago | (#209187)

So, it sounds like a good idea, but what is the environmental impact of a break in that pipe with that liquid nitrogen in it? Ain't it going to go liquid to gas awful damn fast?

Re:It'll last about an hour... (2)

Surak (18578) | more than 13 years ago | (#209191)

That's so funny because it could be true!

And that would be Sunday! Sunday! Sunday! At the Pontiac Sil-verdome! dome! dome!

-- A dyed-in-the-wool Detroiter

Maybe you ought to think ...watch that knee! (1)

FatSean (18753) | more than 13 years ago | (#209192)

And perhaps read the article? The wire itself isn't made of poisonous material. And if the enclosing pipe breaks it'll release Nitrogen into the atmosphere. You know, the same atmosphere we breath...which is a bit over 75% Nitrogen.

Watch that knee!

Holy Crap! (2)

FatSean (18753) | more than 13 years ago | (#209193)

I hope all the engineers working on this project have thought of this! Quick, what's the number for their offices so I can warn them!

Re:interesting..but.. (1)

Wonko the Sane (25252) | more than 13 years ago | (#209194)

If the nitrogen is kept at the right pressure, then it doesn't even have to be kept cold


Yes, but this would be useless for superconducting applications. The whole point is for it to be cold, or else the superconductor won't work.

Re:interesting..but.. (1)

MrChips (29877) | more than 13 years ago | (#209195)

Liquid nitrogen is cheap!!. If the nitrogen is kept at the right pressure, then it doesn't even have to be kept cold. Pressurized lines are already in use for gas and steam. I'm sure that liquid nitrogen isn't much different.
Nitrogen, like hydrogen, helium, oxygen, methane, and lots of other gasses cannot exist as a liquid at room temperature under any pressure. I used to work in a lab where we used alot of lN2 and the number one rule was "never seal a container with lN2 in it". If a container ever did have to be closed, it was done so with some sort of stopper or cork that would easily pop off the moment the pressure rose. If you do seal in some of one of these liquids and let the temperature rise, the liquid will turn to gas and exert extreme pressure on the container. This is the reason why hydrogen and natural gas powered cars are not popular.

Also, superconductors that conduct at lN2 temperatures do so not because they are surrounded by lN2, but because they are at or below the boiling temperature of lN2 under standard pressure. Even if you could keep the lN2 liquid at a higher temperature by pressurizing it, the superconductor would still cease to superconduct the moment it's threshold temperature is reached. The good news is the superconductors produce no heat so all that's needed to keep the lN2 around is good insulation.

Finally, both gas and steam are gasses.

Re:interesting..but.. (1)

MrChips (29877) | more than 13 years ago | (#209196)

If anyone is interested, I just looked up the critical point for nitrogen at webelements.com [webelements.com] . It's 126.2K [or -146.9 C (-232.4 F)]. Regardless of the pressure, it is not possible to liquify nitrogen (or keep it liquid) above this temperature.

Re:interesting..but.. (2)

norton_I (64015) | more than 13 years ago | (#209203)

No, he is right. I don't know where you took your thermodynamics classes, but you were misled. All materials have a "critical point" above which there is no liquid state. To be more precise, there is no liquid-gas phase transition -- in fact what you get at high pressures is a mush that transforms smoothly from "mostly liquid like" to "mostly gas like", but there is never any 2 phase seperation.

For N2, the critical point is below room temperature.

I suspect that there was at the very least a pressure release valve somewhere on your ln2 tank.

Finally, I suppose they could use N2 based vapor cooling along the length of this pipe, but they would have to be screwed in the head to want to. You would have to build the whole system to withstand several thousands of psi with controlled bleed valves the whole way. It is much, much simpler to pump low temperature lN2 the whole way where your equipment only has to handle a small pressure over 1 atm.

Re:how safe is it? (2)

norton_I (64015) | more than 13 years ago | (#209204)

Well, like any electric line, the person who cut it is in a world of hurt. Presumably the lN2 system has some sort of safety shutoff the prevents it from pumping too much lN2 out of a rupture, but even so, there could be enough cold nitrogen gas in the area to suffocate someone nearby.

It sounds from the article like this isn't likely to be a problem in their location: They are doing this because it is so hard to dig there.

Re:RTSC (2)

norton_I (64015) | more than 13 years ago | (#209205)

The cool thing about MgB2 is that people are hoping they can "tweak" it to superconduct above the magic 77K (the cupric oxide semiconductors were also discovered with a Tc around 40K, and quickly improved), while still being easier to work with than ceramic superconductors and more importantly, it points to new areas of research that might improve our understanding of superconductors in general, possibly leading to mugh higher temperature supercondutors

Re:Liquid nitrogen? (5)

norton_I (64015) | more than 13 years ago | (#209206)

Actually, it should be substantially cheaper. High power underground lines, including these ones, are usually oil cooled. Oil cooling is pretty expensive, since you have to somewhere dissipage quite a bit of heat. Liquid nitrogen is cheaper than water, and the superconductor doesn't produce any heat.

People are also looking at using this kind of wire in high power electric motors and transformers for the same reason -- not efficiency, but size and cost.

Liquid Nitrogen spill? (1)

signe (64498) | more than 13 years ago | (#209207)

OK, maybe this is covered in other material, but it wasn't in the article. What happens if the cable breaks? I realize that once the liquid nitrogen gets out of the pipe, it will evaporate pretty quickly. But it's still a hazard, over and above the electrical current.

-Todd

---

Re:Eliminate power outages?? (1)

rtaylor (70602) | more than 13 years ago | (#209210)

It's lossy enough that California can't easily buy power from other states or countries which have the power. Ontario is going to bring back Bruce B nuclear power plant (more than enough to power a few small cities). Not because we need it now, but we may in another decade or so. I'm sure British Energy is willing to sell the power being generated to the south. Good luck getting it there though.

Re:interesting..but.. (2)

mduell (72367) | more than 13 years ago | (#209211)

Liquid N2 is very cheap (a gallon of LN2 is cheaper than a gallon of milk in most places). Also, if you keep it presurized, then you don't have to worry about keeping it cold since it can't expand.

Mark Duell

Re:Eliminate power outages?? (1)

diablovision (83618) | more than 13 years ago | (#209215)

Notice the words "carrying capacity" in what you just quoted? That means they can ramp up the amount of power carried by the lines which risking burning them UP!

Re:how safe is it? (1)

mr (88570) | more than 13 years ago | (#209218)

Ya, thats why its +60% of the air we breath is Nitrogen.

Re:interesting..but.. (1)

Darth Yoshi (91228) | more than 13 years ago | (#209220)

As others have pointed out, LN2 (liquid nitrogen) is very cheap, but that's not the issue. It merely has to be cheaper than doing it the conventional way.

Re:interesting..but.. (2)

jmv (93421) | more than 13 years ago | (#209221)

If the nitrogen is kept at the right pressure, then it doesn't even have to be kept cold.

Well, the whole point of having liquid nitrogen is to keep the supraconductor cold... There's no point in having liquid nitrogen at room temperature.

Re:hm.... (1)

emmons (94632) | more than 13 years ago | (#209222)

Uh... the atmosphere is 79% nitrogen already. I wouldn't be too worried about that.

The thing I would worry about is the cable catching fire at the point it breaks, but that's a safety issue rather than an environmental one.

----

Re:No. (1)

emmons (94632) | more than 13 years ago | (#209223)

Where are you from anyway? I'm assuming it's the US based on the sorry state of education there.

Hey, don't judge us all based on the comments of a few idiots..... oh wait, nevermind.

----

Environmental aspect? (2)

_Mustang (96904) | more than 13 years ago | (#209224)

From the American Superconductor site link I wasn't able to determine any details of the actual manufacturing process. It does indicate that the there are "oxide compounds" involved - but..!

I also couldn't find any indication of the life of this. How long until it begins to breakdown, and when it does what compounds will be released into the ground? And what does the manufacturing process put into the atmosphere in the way of by-product gases and other exhaust? If I understand correctly there is a stream of coolant (liquid nitrogen!) inside the pipe bundle - what happens if the pipe breaks? And of course - what are they going to do with all that cable that was ripped out..

Sounds like a neat idea, but not enough info for me to decide if they really thought this through..

liquid nitrogen and savings (5)

jharper (98953) | more than 13 years ago | (#209225)

Using liquid nitrogen, while expensive, will certainly save money. Our current power grid can lose twenty percent or more power in transit. Keeping a constant flow of liquid nitrogen is pittances compared to the enormous savings of a 25% increase in power distribution. That's a LOT of power. Granted, we won't reap the benefits of this until after much of the United States has better power cabling, but this is just a start. |JH|

RTSC (3)

cybercuzco (100904) | more than 13 years ago | (#209226)

The article also talks about magnesium diboride, a newly discovered metallic superconductor, but they make it out to be more than it atcually is. They say it conducts at twice the temperature of similar conductors, which is true, but it still conducts at a lower temperature than what theyre using in detroit. Yes its metallic, yes it superconducts at liquid nitrogen temperatures, but i dont think itll revolutinize things any more than the current crop of ceramic conductors. Give me a room temp superconductor and the world will be a different place, until then the revolution moves slowly.

Liquid nitrogen? (1)

Killio (102774) | more than 13 years ago | (#209227)

It sounds pretty expensive - will the extra efficiency be worth all the money spent on liquid nitrogen? Anybody have any stats about this?

Re:Environmental aspect? (1)

Nutt (106868) | more than 13 years ago | (#209228)

Wouldnt really matter anyway because we took the nitrogen from the atmosphere so it's not like we're putting anything bad back into it.

Re:Wow... we've seen this before. (1)

Temkin (112574) | more than 13 years ago | (#209229)

Yes... But this time there's more details. Think of it as "followup", which is sorely lacking in virtually all other "news" media.

Temkin

Re:interesting..but.. (1)

Kwelstr (114389) | more than 13 years ago | (#209230)

Of course, if you are a Chem E and you I am wrong, then please enlighten us!!

uh? Are you the grammar nazi or not? Second post with a second gramatical error.

Tsk tsk tsk

Woah, imagine the size of that magnetic field (2)

Kwelstr (114389) | more than 13 years ago | (#209231)

Heh, if you happen to have a steel plate in your head, better make sure you don't walk over that underground superconducting cable, else your head could get glued to the ground.

That will be funny. Also, imagine all the lose coins that this thingy will collect...

Re:interesting..but.. (1)

snarkh (118018) | more than 13 years ago | (#209232)

Cable gets cold and becomes a superconductor. Nitrogen is still piped around at room temperature or, more accurately, underground temperature. The only cold nitrogen was the stuff that was allowed to escape to become a gas.

Informative? Perhaps. Wrong? You bet!

The gas that escapes is actually hotter than the rest of the liquid, and takes energy away from it. Thus the liquid becomes colder. You have to apply energy to remove the vapor, so overall you lose energy. (Otherwise you would have a perpetuum mobile.)

How can a cable get cold from contact with liquid which is at room temperature? Think about it for a second.

Re:Environmental aspect? (1)

rcw-home (122017) | more than 13 years ago | (#209233)

Well, it's slightly more complicated than that. Once the nitrogen leaks out and the ceramic loses its superconductive properties, the megawatts (they said 14000 homes split over three cables) running through that cable will make it heat up faster than a light bulb filament, igniting the cable's insulation. It could possibly become hot enough to ignite aluminum and other light metals that may happen to be nearby.

It's a safety issue, not an environmental issue. I hope they include an automatic temperature shutdown feature.

Re:Environmental aspect? (1)

rcw-home (122017) | more than 13 years ago | (#209234)

Yes. Stuff could still catch fire in the meantime though.

Re:interesting..but.. (1)

ikeleib (125180) | more than 13 years ago | (#209236)

1. Liquid Nitrogen is cheaper than beer.

2. Because superconductors offer zero resistance, they also do not become hot. The only gain of heat (and need for more liquid nitrogen) come from losses to the air (conduction, radiation).

If it wasn't cheaper, they wouldn't do it.

what a joke (2)

small_dick (127697) | more than 13 years ago | (#209237)

I'm sorry, I doubt this project will ever pay for itself. for 1500 ft. they would have been far better off using another low loss system, like UHV or something.


Treatment, not tyranny. End the drug war and free our American POWs.

Re:liquid nitrogen and savings (1)

Milalwi (134223) | more than 13 years ago | (#209238)

First, this really is a neat thing. However...
Our current power grid can lose twenty percent or more power in transit.
Keeping a constant flow of liquid nitrogen is pittances compared to the enormous savings of a 25% increase in power distribution.

Where are you getting that number(25%)? In the studies I have done, modeling the transmission network down to the sub-transmission (roughly 34kV) I saw about 5% loss. I seriously doubt there's another 20% in the distribution network. Another 5%, maybe. After all, the distribution network is pretty much analogous to the "last mile" of data transmission. About 95% plus of the distance traveled along the electrical network is on the transmission(138kV and above, probably higher) system.

Re:interesting..but.. (2)

bellings (137948) | more than 13 years ago | (#209240)

Can you propose some mechanism where the nitrogen gas would "slurp up enough energy to cover it's (sic) latent heat of condensation" that didn't involve what we commonly think of as a temperature differential?

I didn't pay nearly enough attention in my PChem class, but I did pay some attention in the diff. eq., and I don't remember many situations where a cold material would transfer heat to a warm material. Can you elaborate on this?

Re:Liquid nitrogen? (2)

bellings (137948) | more than 13 years ago | (#209241)

Grammar Nazi, you really must stop drinking on Sunday nights. Barring that, you must teach yourself to post as an anonymous coward when you are drunk. I don't believe you've managed to nail a single homonym all evening, and it's really grating on my nerves.

Uhmm (1)

tcc (140386) | more than 13 years ago | (#209243)

" this summer Detroit Edison will lay 1200 feet of superconducting power cable near their Frisbie "

Uhmmm, I dunno about you, but that's gonna be one hell of a frisbie to throw.

Environmental impact of nitrogen (1)

elegant7x (142766) | more than 13 years ago | (#209244)

In my opinion, any one worrying about the environmental impact of releasing nitrogen gas should be shot in the head immediately.

Rate me [picture-rate.com] on picture-rate.com

you idiot. (1)

elegant7x (142766) | more than 13 years ago | (#209245)

Yes, I'm sure the city of Detroit hasn't done any estimation or analysis, and has no idea how much this will actually cost, unlike some random slashdot poster who must clearly be some kind of electrical infrastructure idiot savant.

Of course you must be right, what was I thinking. I mean, you have so much support to go a long with your opinion. Christ, how the hell did a fucking idiot like you get +2?

Rate me [picture-rate.com] on picture-rate.com

No. (1)

elegant7x (142766) | more than 13 years ago | (#209246)

The magnetic fields around an electrical conductor actually rotate around the core, rather then attract it; counterclockwise, if you were facing the current flow. A coil will produce a nice directed magnetic flow, though.

Also, coins do not contain ferromagnetic elements.

Where are you from anyway? I'm assuming it's the US based on the sorry state of education there.

Rate me [picture-rate.com] on picture-rate.com

OH... MY... GOD!! (1)

elegant7x (142766) | more than 13 years ago | (#209247)

According to the second law of thermodynamics the amount of energy needed to cool all that wire cannot, according to the law, be less than the energy saved by the reduction in resistance, because that would decrease entropy, which is impossible.

That isn't even remotely True. It wouldn't decrease entropy; it would just bring the rate of entropy creation down to zero (or near zero). Or are you saying everything has an equal amount of efficiency?

God, why are so many people so stupid!

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Re:No. (1)

elegant7x (142766) | more than 13 years ago | (#209248)

how so?

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No (2)

elegant7x (142766) | more than 13 years ago | (#209249)

Nitrogen gas is not a hazard unless it can displace all of the oxygen in the aria.

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Re:Environmental aspect? (1)

Ig0r (154739) | more than 13 years ago | (#209252)

Wouldn't the act of the wire melting/burning cause the cable to self destruct and stop conducting?

--

Re:Environmental aspect? (2)

Ig0r (154739) | more than 13 years ago | (#209253)

If the pipe breaks then the nitrogen will boil and release gas back into the atmosphere, which is over 70% nitrogen anyway.
It could easily be detected by loss of pressure in the section of broken pipe.

--

Re:new dangers... (3)

Ig0r (154739) | more than 13 years ago | (#209254)

You'd better think a little more slowly next time.
The pipes that carry the nitrogen and wire will be buried, and any escaping liquid would quickly evaporate.
Also, nitrogen isn't flammable. It's the major componant of our atmosphere.

--

Re:interesting..but.. (1)

child_of_mercy (168861) | more than 13 years ago | (#209256)

Doesn't have to have a constant flow.

Superconductors conduct heat as well as electricity near perfectly.

so the temperature will be evenly distributed

Re:hm.... (1)

child_of_mercy (168861) | more than 13 years ago | (#209257)

how dumb are u?

where do u think they get the Nitrogen from???

It's ubiquitous and harmless in air

Admittedly u'll asphyxiate if you're trapped over the stuff venting, but that close u'd be worried about the loose high-voltage cable.

interesting..but.. (1)

fjordboy (169716) | more than 13 years ago | (#209258)

I don't understand how they can have the constant flow of liquid nitrogen...won't this send the price of the whole operation up really high? does anyone have any information on how they plan on implementing the liquid nitrogen?

I think it is pretty cool that superconducting is actually gonna be used for something bigger than laboratory tests. :)

Re:Liquid nitrogen? (1)

Busiris (172301) | more than 13 years ago | (#209259)

This was due to DPL not DTE. DPL supplies power to all city owend property and city offices.

Dig Safe (1)

karandago (174156) | more than 13 years ago | (#209260)

Man there are problems involved with people digging and hitting power lines and water mains now, imagine the sheer terror caused by hitting a liquid nitrogen line.

I can see the newscast now Two men frozen to death while digging in their back yards, power to the city is out until the liquid nitrogen pipe can be fixed
I love the concept of superconductors, but I kind of wonder about the feasability of mag-lev and power lines and the like without high Tc Superconductors.

silly slashdotters, learn about refrigeration. (1)

chompz (180011) | more than 13 years ago | (#209261)

Ok, people, look at your refridgirator, air conditioner, or something please. How do they work? The "coolant" is cooled by being highly presurized (squeezing heat out) and then quickly depresurized, causing it to absorb a great deal of heat. Any student of thermodynamics would be able to tell you that. So, what they will do with the liquid nitrogen is exactly what they do in your air conditioner, except capable of cooling to levels which the freon or amonia (some ac's) would freeze solid. Why do you think this liquid nitrogen will ever exist at room temperature after it is initially cooled. Refrigerant/ac systems use internally cycled refrigerant, which always stays cold. Better performing AC's use a method observed in fish's gills increase O2 intake, running un-oxygenated and oxygenated blood in oposite directions through the gills. The same could be done with liquid nitrogen, running it both ways through a bi-layered pipe, or a pipe composed of woven tubes.

Re:interesting..but.. (2)

Alien54 (180860) | more than 13 years ago | (#209262)

according to the article, Liquid Nitrogen is about 10 cents a liter.

this looks like the first run for power transmission over superconducting lines. So even if this is break even otherwise, there is a bonus in the practical experience you would gain just in maintaining the thing. Little stupid things like "apply rubber hammer here" stuff.

so it is worth while just for that

Check out the Vinny the Vampire [eplugz.com] comic strip

Re:Liquid nitrogen? (1)

AaronStJ (182845) | more than 13 years ago | (#209263)

It sounds pretty expensive - will the extra efficiency be worth all the money spent on liquid nitrogen?

Well, if you'd RTFA, you'd know that is is. While they don't give actual stats, they do mention that liquid nitro is "cheaper than kool-aid."

Re:Woah, imagine the size of that magnetic field (1)

AaronStJ (182845) | more than 13 years ago | (#209264)

Since the cable is run in a straight line, not couled or anything, I imagine that the magnetic field it threw off would not be that major. Also, since the power lines must run both ways, coming and going (at least, I believe that's how it works to close the circuit), I'd think the magnetic fields would pretty much cancel each other out.

Re:what a joke (1)

AaronStJ (182845) | more than 13 years ago | (#209265)

I'm sorry, I doubt this project will ever pay for itself. for 1500 ft. they would have been far better off using another low loss system, like UHV or something.

I believe the idea of the installation is more of a proof of concept thing. If they can get superconductors to work for 1,500 ft., then the city is a lot more likey to sink money into a larger scale project, rather than an unproven technology.

Does it hover? (2)

doorbot.com (184378) | more than 13 years ago | (#209267)

While supercooling my overclocked toaster?

"It'll flash fry a buffalo in 30 seconds..."
"Aww, but I want it now!"

Re:It'll last about an hour... (1)

nekid_singularity (196486) | more than 13 years ago | (#209270)

I hate to be so god damn pedantic (actualy, I live for it), but the nitro they refer to is nitromethane, but I am sure you already knew that.

Eliminate power outages?? (1)

ZeLonewolf (197271) | more than 13 years ago | (#209271)

For 90 years, scientists have dreamed about the eye-popping potential of superconductors. Superconductivity could make copper wire obsolete, shrink the size of motors by four-fifths and increase the carrying capacity of power grids by orders of magnitude. Brownouts and rolling outages like those plaguing California could become a thing of the past.
Is our power grid THAT lossy? This seems to be a bit on the grandiose side...more efficient cabling will certainly help, but I doubt that world's energy needs will be met by a mere decrease in transmission losses.

Re:interesting..but.. (1)

ZeLonewolf (197271) | more than 13 years ago | (#209272)

Hmm, well, you're right on that: 10 cents per litre, according to the article...but I imagine that if this takes off, they might be able to find a way to extract it from the air, which is roughly 75% N.

Re:Liquid nitrogen? (2)

grammar nazi (197303) | more than 13 years ago | (#209273)

I know that 2 summers ago, there were many problems with rolling brownouts and whatnot, do to a screwed up grid in the Detroit area. This cable will be a welcome relief!

The grammar nazi happens to have a large amount of Stock in DTE Energy, hence anything that makes money for Edison, eventually lines the grammar nazi's pockets!!

Re:interesting..but.. (2)

grammar nazi (197303) | more than 13 years ago | (#209274)

Liquid nitrogen is cheap!!. If the nitrogen is kept at the right pressure, then it doesn't even have to be kept cold. Pressurized lines are already in use for gas and steam. I'm sure that liquid nitrogen isn't much different.

Of course, if you are a Chem E and you I am wrong, then please enlighten us!!

Re:interesting..but.. (2)

grammar nazi (197303) | more than 13 years ago | (#209275)

With all due respect MrChips, I've had one undergraduate course and one graduate course in Thermodynamics, and I've never heard of this. In addition, I've done much electron microscopy using liquid nitrogen from a large tank, that was completely sealed and at room temperature.

According to physics, the liquid will stay a liquid. It will exert a high pressure, but it will remain a liquid and it will remain at room temperature.

I'm sorry if this surprises you.

Keeping the superconductor below temperature has to do with vaporizing *some* of the Liquid N2, just enough to keep the cable cold. The room temperature liquid is kept separate from the superconductor until it is needed.

Re:interesting..but.. (2)

grammar nazi (197303) | more than 13 years ago | (#209276)

I stand corrected. Now I remember those diagrams with the pressure, temperature, and phase !!

Sorry. I guess a was a little to forward with my comments. I'll make sure I only post what I completely understand from now one.

Re:interesting..but.. (4)

grammar nazi (197303) | more than 13 years ago | (#209277)

Yes, but this would be useless for superconducting applications. The whole point is for it to be cold, or else the superconductor won't work.
Thermodynamics 101:

1. Pressure is released from room temperature Liquid nitrogen.

2. Liquid Nitrogen becomes gas.

... Wait, it can't become a gas unless it slurps up enough energy to cover it's latent heat of condensation. Enough energy get's absorbed to cause the surroundings to get cold (-195 Deg C. cold).

5. Cable gets cold and becomes a superconductor. Nitrogen is still piped around at room temperature or, more accurately, underground temperature. The only cold nitrogen was the stuff that was allowed to escape to become a gas.

Detroit Edison?? (1)

ilsa (197564) | more than 13 years ago | (#209278)

Perhaps the nice folks at DTE should work on actually providing reliable energy. Weeklong power outages are routine after any kind of storm. And they have the absolute chutzva to claim that burying cable wouldn't reduce outages, only make them more expensive to fix. So tell me, how does hail, wind, rain, ice, or tornadoes effect underground cables?

Re:interesting..but.. (1)

groomed (202061) | more than 13 years ago | (#209279)

get's absorbed

You, sir, are an utterly worthless grammar nazi.

how safe is it? (1)

Technodummy (204943) | more than 13 years ago | (#209281)

what happens if it's cut? anyone have any idea? just curious

Re:interesting..but.. (1)

smnolde (209197) | more than 13 years ago | (#209282)

I am a ChE, but I won't enlighten you too much. I didn't do too well in thermodynamics, but if you know anything about thermodynamics, you know that:

1. Energy can be changed from one form to another, but it cannot be created or destroyed. (You will always pay a price for convenience.)

2. [I]n all energy exchanges, if no energy enters or leaves the system, the potential energy of the state will always be less than that of the initial state. (You never get out of a system what you put in.)

And my mom's favorite:
3. All systems tend to favor the lowest state of energy or entropy. (No matter how much you work at cleaning your room, it will never be perfect.)

So there. All that is wished is that the energy saved costs more or equal to the cost of implementing this liquid nitrogen system.

Think of the economy ! (1)

Rosco P. Coltrane (209368) | more than 13 years ago | (#209283)

Wow, so they have this great long power line in a pipe surrounded by liquid nitrogen : how about building a giant linear sperm bank at the same time ? they could install a miniature conveyor belt in the cooling pipe to store the test tubes.

"A door is what a dog is perpetually the wrong side of" - Ogden Nask

Re:Entropy (1)

GMwrench (211439) | more than 13 years ago | (#209284)

You have got your thinking crooked. By your argument lower temp superconductors would have lower restance than high temp ones that is not true.

Consruvatation of energy has nothing to do with the energy to obtain or maintain superconducting. That is why room temp superconductors would be so good.

Nitrogen-related brownouts? (1)

Chazmati (214538) | more than 13 years ago | (#209285)

So I wonder (not having read the article, flame if you must) how often these 14,000 residents will have to deal with reduced power due to refrigerated nitrogen problems. What fraction of full power do you figure the unrefrigerated cables can carry? Complicated feats of engineering often precede complicated problems.

Re:No. (1)

funkbrain (217835) | more than 13 years ago | (#209286)

You're an idiot.

Re:interesting..but.. (1)

excesspwr (218183) | more than 13 years ago | (#209287)

Thermodynamics 101: 1. Pressure is released from room temperature Liquid nitrogen. 2. Liquid Nitrogen becomes gas. ... Wait, it can't become a gas unless it slurps up enough energy to cover it's latent heat of condensation. Enough energy get's absorbed to cause the surroundings to get cold (-195 Deg C. cold). 5. Cable gets cold and becomes a superconductor. Nitrogen is still piped around at room temperature or, more accurately, underground temperature. The only cold nitrogen was the stuff that was allowed to escape to become a gas.

It is too late and I am too drunk to moderate this as informative, but it is. So if the rest of you could do it for me...I'll owe you a karma point.

Re:liquid nitrogen and savings (3)

3-State Bit (225583) | more than 13 years ago | (#209289)

Using liquid nitrogen, while expensive, will certainly save money. Our current power grid can lose twenty percent or more power in transit. Keeping a constant flow of liquid nitrogen is pittances compared to the enormous savings of a 25% increase in power distribution. That's a LOT of power. Granted, we won't reap the benefits of this until after much of the United States has better power cabling, but this is just a start. |JH|
I wonder though. The article says 1200 feet...one would think the vast majority of your "twenty percent" (although it surprises me that it could really be so high) is either in the megawatt long-distance things (what you drive next to and oooh at), or else power loss in house wiring or in downstepping the current to it. Between the two, relatively little of the length of wire that's in our power grid is over distances of 1200 feet...and if you started doing ALL wiring with this system, it would get really expensive. The way to do the estimation right is to figure out:
  1. Over which "type" of wiring are we looking at the most significant power loss?
  2. How much of this is convertible to superconducting?
  3. What is the percent loss in power?
  4. What is the current cost of power?
  5. What is the current 'marginal' (ie. minus base overhead, looking at what "one more foot" would cost) cost/foot of carrying the power?
  6. What is the 'marginal' "superconducting" cost/foot of carrying the power?
  7. What is the base cost to setting up an area with superconducting?
  8. What is the running cost of superconducting? (In this case keeping a flow of liquid nitrogen).
Give me these data and I'll tell you whether it's worth it -- or even remotely feasible. If it's something like "damn-near break even" then it's probably a good sign -- this is first-generation stuff. From what I know about silver-clad HTS ceramic ribbons, though (ha!), I would guess that this is unreasonable expensive technology.
~

Re:interesting..but.. (1)

hillct (230132) | more than 13 years ago | (#209291)

think it is pretty cool...
Yah. Vary cool. Aprently just above minus 321 degrees Fahrenheit.


--

Re:interesting..but.. (1)

Oswald (235719) | more than 13 years ago | (#209292)

Just pray he doesn't try to become the number nazi instead.
1.
2.
uh..?
5.
We would be left trying to discern shades of worthlessness.

My question (and I think yours) (1)

AKAImBatman (238306) | more than 13 years ago | (#209293)

To everyone who has responded that liquid nitrogen is harmless, I believe the question was more about what if something sparked and ignited this stuff? I do know from my limited experience with using it for shipping (don't ask) that it is generally pretty safe stuff, but still... Anyone have a good answer to this?

insulation, insulation, and insulation (1)

MillionthMonkey (240664) | more than 13 years ago | (#209294)

If the insulation is sufficient, then only a very small amount of nitrogen would be necessary for the entire system because the superconductors themselves will not be contributing any I^2*R heating. Except for a larger amount of nitrogen consumed during the initial cooling-down process, the nitrogen cost during steady-state operation is directly proportional to the heat energy getting through your insulation. The insulation's heat conductivity can be made arbitrarily close to zero (although the better it gets, the more expensive it is). I would imagine that to reduce nitrogen costs they would use a structure analogous to a Dewar flask along the entire length of the line. If they did, then they would only need a slow trickle of liquid nitrogen along the entire length of the line.

Re:Eliminate power outages?? (5)

RavStar (252707) | more than 13 years ago | (#209295)

The power grid is so lossy, you can power a house by setting up a capture coil near a high tension line. Or, you can light up a florescent light by just holding it near one. We loose 20% of our generated power by the air and resistance loss from the power grid. If we replaced all high tension lines with this technology, we would have 15-20% more power without ever building a new power plant. Plus, we could efficiently move power where it is easy to make it (nuke, hydro, wind) to places it cant be made easy. With a super-conducting power rail from one coast to the other, we would have the ability to send power from one end of the nation to the other with less than 1% loss. This is only a dream with copper and Al cable.

Re:interesting..but.. (3)

Topgun1 (261377) | more than 13 years ago | (#209296)

Alright. You asked for a chemical engineer, you got it. Whether liquid nitrogen is cheap really depends on the process you use to compress it for reuse. To answer your question about the cold, yes, in this case it does have to be kept cold. However, you can liquify nitrogen at temperatures much higher than that at 1 atmosphere. It's all about phase diagrams, which are functions of temperature AND pressure. So, if you put enough pressure on the gas, you can have a liquid at relatively "high" temperatures. There is such a thing as a supercritical fluid, but that is way beyond the scope of this discussion.

The interesting part here, at least from a transport aspect, is going to be the heat transfer. That is, you have to REALLY insulate them lines, or else you will vaporize the liquid notrogen in the line and potentially lose the superconducting capability of the ceramic. This is especially true, since you have a difference in pressure accross the power line (this pressure drop is what allows the liquid to flow). Again, from phase diagrams, pressure and temperature dictate the phase. So unless Q (the heat flow in the system) inside the line is very low (close to adiabatic), this could be a very tough engineering problem. This is especially true when you consider that even a small change in the environment might cause an incredible amount of change in the process as a whole. My congratualtions to the team of engineers that pulled this one off.

Re:Eliminate power outages?? (1)

astr0boy (265689) | more than 13 years ago | (#209297)

if i remember correctly loss is about 20%. which IS a big deal

-----

Re:interesting..but.. (1)

dhovis (303725) | more than 13 years ago | (#209298)

The quoted figure for liquid N2 is about 10c per liter.

This does not mean that liquid nitrogen trucks will have to pull up every couple of days or so. All you really need is a super heavy duty refrigerator to keep the nitrogen cold enough to stay liquid.

There is a company called Illinois Superconductor [iscointl.com] that makes filters for cell phone base stations. You wouldn't even know there was liquid nitrogen in their products, the filters just have an integrated cooling system that keeps the nitrogen inside (and hence the superconductor) cold.

Obviously the cost of this cooling system has gotten down to the point where it is profitable, otherwise I don't think Detroit Edison would be doing it.
--

This is Bigger than just Power Cables (1)

XBL (305578) | more than 13 years ago | (#209301)

This is the first step towards changing the world's infrastructure. Power and communications are the major benefactors, of course.

With superconductors allowing small, powerful, efficient electric motors... I would bet on electric cars taking over all else in my lifetime.

Heck, maybe these new motors will let people drive their 2050 Ford Monster-SUV with a clear conscious.

Re:Dig Safe (1)

canadian_right (410687) | more than 13 years ago | (#209306)

Your diggers (who deserve a darwin award for not calling the usual numbers before digging) are in much more danger from the electricity thatn the liquid nitrogen. You watch to many movies. Unless your digger bathes himself in the LN2 on purpose he isn't in any danger of being frozen.

Re:Liquid nitrogen? (3)

canadian_right (410687) | more than 13 years ago | (#209308)

Its a test basicly, they aren't too concerned with cost. Why bother at all? No one wants new overhead wires in their neighborhood. Putting BIG transmission lines underground is VERY expensive. Using superconducting cable you can use an existing small tunnel and put a LOT more electricity through it. It will only be economical in urban areas for many years to come. As for safety, superconductiing or not, shorts etc... are detected and the power is shut off automatically. Its a normal part of the design of any transmission and distribution system. I'm sure they will be monitoring the pressure of the liquid nitrogen, and a drop in pressure will trigger safety shut offs. This sort of "protection and control" is completley routine.

Just for reference, liquid nitrogen costs about the same as milk, and is not much more dangerous unless you stick and hold your hand in a vat of it.

Re:Pressure? (1)

drhemi (414356) | more than 13 years ago | (#209311)

You're effectively doing the same thing. By heating the water the vapor pressure of the water overcomes the pressure that the air is putting on the water and the water boils. A vacuum removes the air pressure so that the vapor pressure of the water is higher and it boils. I'm sure you already knew that though; from high school.

Re:RTSC (1)

Genyin (415163) | more than 13 years ago | (#209312)

There is the definite advantage that, as a metal, it should be ductile. One of the biggest issues with superconductors is making them into a wire... ceramic is rather brittle.

Re:how safe is it? (2)

Genyin (415163) | more than 13 years ago | (#209313)

Imagine yourself being electrocuted and frozen to death at the same time... also the power would probably go out...
Not much different, I'd think, than standard high voltage wire.

Pressure? (1)

Publicus (415536) | more than 13 years ago | (#209314)

I'm not a chemist, rather a former high school chemistry student. Somewhere back in the confines of my limited memory I find something about curves and temperature and pressure. I.E. you can boil water at room temperature if you create a vacuum or something. Is the idea to keep the pressure in the pipe high enough so the Nitrogen doesn't convert to gas? Is that an issue? They're referring to -380 degrees farenheit as a high temperature. Wow. Anyway the potential here sounds absolutely incredible. This is really cool.

Peace, and stay cool! hehe :)

Superconductor Cables and other stupidity (1)

nilu (453773) | more than 13 years ago | (#209317)

Superconducting cables are great in a protected area. The amount of energy carried by those cables will be such that it can really blow up better half of the city. Because you can not see electricity does not mean it is not there. This country need Electrical Engineers ... why 1. 110V, 60Hz Distribution system. Eats more copper and generators got to run faster. 2. Power outlets without any switch ! I can't imagine that. If you want to see the the real power plugs, check what Brits did - the got more senses in that are at least. 3. Power cables without ground--another sin, all two pin cables must be banned. 4. Power shortage in CA ??!! Talk about bad planning and middle management/politicians running the infrastructure. But, who am I to say, everybody is busy making money in the DOT-COM ... no real engineers needed anymore just sit down and code and have some stupid guys keep the cities running.
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