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Superconducting Power Cables in Denmark
Mikkel Blanné writes "Today Denmark put a superconducting power cable to use , beating Detroit to it! (Be careful though, it's in danish). We're talking 3 cables, each 30 metres in length and produced in cooperation between Nordic Superconductor Technologies, NKT Research and DTU.
This makes it the first superconducting cable in actual use, ie. not in a laboratory. The purpose of this project is of course still research, but I am right now typing this on a computer running on power that came through those cables ;-)
Further descriptions are here and in this rather old RISØ newsletter. Sorry about everything being in danish, but apparently this hasn't come to the world's attention yet..."
Three 30 metre supercooled cables Copenhagen's new supercable is only 30 metres long, but that is ample for practical full-scale testing in the public supply grid. The cable is installed at 'Amager Substation', a central hub in the Danish capital's energy supply system. The supercable is capable of supplying electricity to the whole of Amager district and will be tested under all operating conditions. No operating experience exists elsewhere of superca-bles installed in a public supply grid, and in particular the use of extremely cold liquid nitro-gen to cool the cable is a totally new element in electricity supply. The new cable has three phases, ie. it consists of three separate superconducting cables each 30 metres long spliced into the grid where the voltage is 30 kV. The supercable has a 2000 Amp current rating.
At first only about 20% of the power in the station is led through the cable, but later (if everything goes well) the cable is supposed to take more power.
If this project turns out fine, a 4-6K meter cable is next.
Power for cooling to keep the cable below -160 degrees celcius is expected to be about half the power loss of a traditional cable.
Remember though, that long distance fiber optic cables are power cables. All those repeaters along the way need power, and that is usually supplied with one or more 10,000 volt conductors in the same jacket as the fiber.
An undersea _power_ cable between Europe and America might not be such a bad idea. The timezones are different: during Europe's night time its power stations could sell electricity to the US, and vice versa. I don't think that people will be constructing nitrogen-cooled undersea pipeline-power-cables for a while yet though.
-- Ed Avis ed@membled.com
Yet the total power delivered to these repeaters is so small that the costs to cool the superconductor would make this a completely idiotic investment.
--Be human.
Are you smoking crack? This won't do one bit of good for a 25GB transatlantic cable. Fiber optics are already nearly lossless at large distances. The only problem with fiber optics is that we cannot modulate significant amounts of power over a fiber optic cable.
.01%, but I have absolutely no evidence to back that up).
This is going to be used to transmit power. Right now, in the US, when power is transmitted from the Hoover Dam to cities several states away, power losses can be well above 50%. A fiber optic cable over the same distance would have losses on the order of a fraction of one percent.
This won't be a replacement for the cabling between your house and the transformer in your neighborhood. The costs of supercooling the wire would be too great. This is going to be used to transmit power from the power source to the power station. BIG wires. Big current. High voltages.
So, if you're a comm company, you don't have to worry about this. This won't affect you one bit. In fact, none of the wiring for power in neighborhoods will be uprooted, either. Only the big high voltage, high current cable (actually, if your cable can take higher voltages, you'll gladly trade a higher voltage, lower current cable, as losses are related to current, not voltage). This will be far less than 1% of all power lines (probably smaller than
--Be human.
Actually, 30 meters is just over 98 feet, 5 3/32 inches. :-)
--Joe--
Program Intellivision!
Does anyone know how much these cables would save (in the way of line loss) over ordinary copper power mains?
Don't have a wire table handy and the answer should be generally interesting.
Axtually, as someone else has already pointed out, it it just under 100 ft.
Partly true. The longer the line, the more you gain from reducing the resistance. However, the load current also plays a a large part in this (see below)
The formula is correct, but the v (or more properly e for EMF) is the line drop, which is proportional to both the current, the length, and the resiatance/length. In this case, the more appropriate forumula would be P = I^2 * R, where I is the load current and R is again proportional to cable lenght.
Consider a local main that delivers 200A, is 1000 ft long (300M) and has a resistance over its length of 0.01 Ohm. The drop in each each leg ot the main will be 2V. So if the substation feeding the main delivers 120V, only 116V will be seen at the other end. Further line loss (which will be heating the main) will be 400W in each leg of the main, or 800W. (My reistance value may be way off, I have no real idea what the resistifity of local power mains is.)
Long distance power lines are extremely high voltage (on the order ot tens of KV) and carry relatively low current. Local mains carry only 100 .. 240 V and (relatively) more current.
Also, there are probably more miles (total) of local mains than of
long distance transmission lines.
You aren't ging to have high tension wires there.
The Detroit cable is 1% the weight of the copper
it replaces, and almost twice as efficent.
..that according to the article one reason they're installing the superconducting cables is that it is cheaper to install superconducting cables than "normal" cables!
TA (I read the article)
I'm suprised the audiophile market doesn't have any superconducting products. It seems these people will buy anything as long as it costs enough.
'This makes it the first superconducting cable in actual use, ie. not in a laboratory.'
I think the author (Chick) is a little confused on the term 'actual use.' Just because a superconducting cable is used in a laboratory doesn't mean that the cable itself is the subject of the experiment, and could easily be seen as a case of 'actual use.'
More to the point, the 30m cable is a 20% load experiment which, if successful, will lead to a 100% 'actual use' implementation of several Km, so this Dutch installation isn't really specifically for 'actual use' either.
Kevin Fox
--
Kevin Fox
Under the DMCA a Danish translator could be considered a circumvention device.
See URL http://www.supercables.com (follow the "news" link)
--
Yeah in Detroit... links here and here and here
Danish research, industry and power supply in unified world record.
For the first time in the world superconducting wires are moved beyond the laboratories and into the power grid. It happens monday at Amager Koblingsstation located Irlandsvej 95. The Italian/American competitor Pirelli is believed to be at least a month delayed.
Since february engineers from Copenhagen Energy, NKT Cables, NKT Research and DTU have worked on installing three pieces of superconducting wire at Amager Koblingsstation, monday they're ready to supply great parts of Amager with power.
This is a demonstration project (proof of concept) that through daily maintenance will show whether superconduction techniques are read for the terms of reality. the cables need to withstand the large fluctuations in power and voltage, that occur from time to time. Three cables at each 30 meters of length have been spliced into a section of the normal power grid, on the distribution side, where the voltage is 30 kilovolt.
The initial phase is careful, but as Amager Koblingsstation is capable of supplying power to all of Amager's 150000 inhabitants, the supercables will have theirs to see to.
"Initially the supercables will be in charge of 20 percent of the ordinary power, for as long as we're comfortable using them. Later the load will be increased", says integrational project manager Svend Korning of Copenhagen Energy.
Waste is halved
Not only the cables are on test. An important part of the cooling facility that's needed to keep the superconductors below their critical temperature, minus 160 degrees celcius (-256F), where electrical resistance disappears.
When the test phase is over, the new supercables are to be used across larger distances, typically 4-6 kilometers (1.6-3.75 miles). This is where money is to be made in comparison to traditional power cables, that become 70-80 degrees celcius hot (158-176F) when fully loaded. The dug down cables heat the surrounding ground to no use, that waste will disappear completely when using superconductors.
"In stead there's going to be an extra power usage in the maintentance of the necessary cooling facilities, but that usage is only half the wast of the traditional cables" says project manager Dag Willen of NKT Research.
"The society can save energy on superconductors, but to the power companies it's more interesting that the cables are cheaper to install, as this helps then to be competitive on price. So far things look good. With cables that are several kilomneters in length, expensive high voltage transformers which have been necessary so far, can be saved when the power is to be transported. Furthermore, the supercables are smaller and bend easier" he says.
The demonstration project at Amager has costed 10 million danish crows (~$1.25m), but there are more possibilities of doing this cheaper next time. For examnple, the cables can be produced to take up less space, and allow larger maximum current.
"But for the first round, we've purposely produced a simple cable with the same dimensions as the old" says Dag Willen.
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--
Patrick Doyle
I mod down every jackass who puts his moderation policy in his sig. Oh, wait a sec....
--
Patrick Doyle
I mod down every jackass who puts his moderation policy in his sig. Oh, wait a sec....
Superconducting cables are a Good Thing, but what about transformers? IIRC, we lose about 1/3 of our power in transformer hysteresis (i.e, heating up transformer cores), and there isn't much loss in the high-tension lines since their voltage is so high (and current is so low: resistance works against current, not voltage.)
Of course, if all transmission lines were superconducting, it might not be necessary to step up voltage in the first place (or maybe not step it up quite so high), and just run 240 or 480VAC most of the way.
Come to think of it, didn't Switzerland deploy a megavolt DC system a while ago? That system used DC motors to drive alternators at the point of delivery.
-jcr
The only title of honor that a tyrant can grant is "Enemy of the State."
The refrigerators that keep the liquid nitrogen liquid make a lot of waste heat, but that heat doesn't end up in the conduit with the cable.
Switch to superconducting wire in an existing tunnel, and there is both more electrical capacity and more space for communication cables.
Today's NYTimes is reporting high-temp superconductors being used in Detroit (high temp is a relative term). http://www.nytimes.com/2001/05/29/science/29SUPE.h tml
Someone you trust is one of us.
I'm sure there is some good reason buried in the article, but why exaclty didn't they just move one of the things they are connecting 30m closer?
A pizza of radius z and thickness a has a volume of pi z z a
[Homer stands outside Mr. Burn's office door. He knocks and peers inside.]
Homer: "Ummmm...Mr. Burns?"
Burns: "Yes?"
Homer: "I read on Slashdot this morning that there these Danishes we can get now that are made of superconductors."
Burns: "Hmmmm....If you read it on Slashdot, it must be true!
[Under his breath] (Or so I've heard.)
I'll look into it."
[Homer leaves.]
Burns: "Smithers, who was that neanderthal?"
Smithers: "Homer Simpson, sir. One of your trolls from Section 7-G."
Burns: "Simpson, eh? He raises a good point. As the local energy concern, I've got maintain my competitive edge. Hire more Danes."
Smithers: "But I think he meant..."
Burns: "Enough chatter! Get me more Danes. We'll rend their superconducting little bodies into superconducting wires. Get me more Danes!"
[Pause]
"And Smithers? No Germans. I'm still trying to fix the damage they did to my plant while trying to bring it up to code."
For you americans thats a little over 110ft. I could be misunderstanding this (and i certainly dont speak danish) but I thought the largest gain would be through using this is long distance transmission lines.
As i recall the loss in a cable is P=(v^2)/R so the lower the resistance the lower the loss in the line. As the resistance of a wire is proportional to it's length P=(v^2)/(al) so the greatest losses are on long lines.
None the less this is still a fantastic acheivement and will hopefully pave the way to more widespread use.
>Be careful though, it's in danish
What's wrong with it being in Danish? Has the danish language suddenly become volatile when viewed by a non-dane? Is this another security feature -
YOU ARE NOT AUTHORISED TO VIEW THIS LANGUAGE
YOU WILL NOW SELF-DESTRUCT.
What if some of our readers can actually parse danish themselves? You need a disclaimer on your disclaimer: "Be careful though, it's in danish* (does not apply if you can read Danish.)"
Jeez.
Alex
Feel that power? That's mah MOUSING FINGER
Here is the original web page as auto-translated to English
On another note, there are these stories previously seen on Slash
- Superconducting Power Cable in Detroit by michael on Sunday May 20, @08:21PM EST 221
- Nitrogen Semiconductors by timothy on Thursday May 10, @01:23PM EST 14
- High-Temperature Metal Superconductor Beckons by timothy on Monday February 26, @03:21PM EST 179
I note that the Detroit Story was just a week or two ago, but it is nice to see europeans getting a jump on the US.Check out the Vinny the Vampire comic strip
"It is a greater offense to steal men's labor, than their clothes"
The story says that the cables installing in the power station is ment as a live test to see how the cables will react in a real-life enviroment.
/CARRIER LOST
In the beginning the cables will only take about 20% of the power in the line they have been connected to, but once they feel confident in the cables, they will turn it up.
The power used to cool the cable should be less that 50% of the power lost in a normal cable.
Hmm it just strikes me that I am getting power from those cables, cool, they seem to wo.#%Ffbfkhg
--------
Well conventional thinking requires very high voltages and low currents, since this limits the loss on the cable, it also means the cable can be smaller and therefore limit resistance further.
However, even with a superconductor you'd need a massive cable (and therefore more cooling) to carry high currents, so the old high voltage method is better.
I can't really workout your safety perspective here, it's the current that kills you so it would be even more dangerous. Even with the lowest currents used on the power grid, if you're fried at 4000v or 64,000v you're still fucked either way.
They, DTU/NKT/RISØ, has a long time to come up with this cable wich consists of the powder Bismuth-strontium-calcium-copperoxid also known as BiSCCO, a material used by most superconductor makers. The powder is poured into a thin silver pile wich is then pressed severel times into a thin superconducting strand. 37 of these are put into a bigger silver pipe. The pipes are cooled to -196 degrees C. The pipes will be able to be pulled thru old cablepipes underground, and will with their reduced heat and lesser magnetism be gentler to the environment. The cables can transport up to 7k amps per square cm. This the article says is little over half of what the americans have in there detroit project (12k amks). While the americans can transport more power, the danish cable is more flexible, lighter and has the lowest energyloss at all. The use of it now is to connect old powerstations to new ones during updating of powerstations. The cables are for now only used in high power cables because they do require alot of power themselfs to keep that low temperature, but the cables do reduce the amount of energy lost in the cables with up to 40% compared to ordinarry copper cables. The article states even though it is a major breakthrough and defenetly the americans have done some great advances too, this is still babysteps. The powder and the creation of the cables has to be perfected and simplified. goals are to make it cheaper to make and be able to have longer cables
There isn't much like the scent of a fresh harddisk
Southwire is still only using superconducting cables in their own factories, ie. in a closed environment. The news is that now it's being used in the public distribution in Copenhagen.
Maybe you should see what they did right here in my home town one year ago! Not too far away from Atlanta, its already been operating for ove a year. How do THOSE guys make the first record? Southwire is one of the largest building wire companies in the world. http://www.southwire.com Southwire Celebrates One Year Of Operating HTS Power Delivery System (Carrollton, Ga.- January 5, 2001) - A year after activating its high-temperature superconducting (HTS) power delivery system, Southwire Company provided a glimpse into the superconductor project's future today as it celebrated the anniversary and the system's recent milestone of operating for 5,000 hours at a 100-percent load.