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Superconducting Power Grid Launches In New York
Posted by
Soulskill
on Sat Jul 12, 2008 02:06 AM
from the so-i-rewired-it dept.
from the so-i-rewired-it dept.
EmagGeek writes "IEEE is running a story about a new superconducting power grid that was energized in April in New York State. The lines operate at 138kV and are cooled to 65-75K to maintain superconductivity. These lines are run underground and can carry 150 times more electricity than copper lines of the same cross section. The project is funded with taxpayer dollars through the Department of Energy."
A related story at MarketWatch indicates that this is part of a large-scale effort to upgrade aging infrastructure.
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I'd contribute funds to that... (Score:5, Funny)
Superconductors = almost no heat (Score:5, Informative)
how much energy does it cost to keep them so cool?
Not as much as you may think.
The whole point of using super conductors is that their resistance is incredibly low, almost 0 ohm. They are thus highly efficient and don't lose much energy into heat through Joule effect, compared to classical conductors used in regular power lines. They will naturally stay cool.
So it costs some significant amount of power to cool them down to their working temperature, but once there, the super conductors keep their temperature almost for free, you only have to make up for what is lost because of the insulation.
Similar superconductors are used in the high-field super-magnet inside medial MRI machines. And those machine doesn't need a whole nuclear plant's worth of energy to keep them cool.
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Re:Superconductors = almost no heat (Score:4, Informative)
The whole point of using super conductors is that their resistance is incredibly low, almost 0 ohm.
No, the whole point of using super conductors is that the resistance is EXACTLY 0 ohm, not incredibly near. There is no resistance, at all.
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Re:Superconductors = almost no heat (Score:5, Informative)
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Re:Superconductors = almost no heat (Score:5, Informative)
You use the right words for an electircal engineer, but your conclusions are inaccurate.
Skin effect doesn't reduce inductive losses. It just means you generally increase resistive losses bceause your effective cross section is reduced. High voltage AC transmission lines are famously inductive, such that transmission line workers where metal mesh in their suits so they don't get the weird feeling of the oscilating magnetic field through their bodies.
And, no, long distance transmission lines are most decidedly NOT DC in the U.S. Now, in Brasil and China, yes, long haul DC transmission lines exist [wikipedia.org]. But they have to pay a huge cost in terms of equipment for this. It's balanced out due to the decreased construction cost and resistive losses. Long haul DC lines are only economical when you have a massive distance between your power generation and utilization, or you're trying to balance load over a rather massive area.
In the area of my ignorance, though, I don't know if inductive losses would ever be significant for a superconductor. One of the defining characteristics of superconductivity is that external magnetic fields only penetrate a tiny distance (~100 nanometers) into the superconductor. I don't know if there might be a similar oddity which prevents them from generating a magnetic field outside of the conductor and coupling with other conductors.
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They can feel the magnetic field? (Score:5, Interesting)
High voltage AC transmission lines are famously inductive, such that transmission line workers where metal mesh in their suits so they don't get the weird feeling of the oscilating magnetic field through their bodies.
That's wild... it is news to me that humans are able to directly perceive even very strong magnetic fields. For example, I don't think patients feel anything when undergoing an MRI [wikipedia.org] procedure. Can you cite a source for this information? Thanks
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Re:Heat from environment (Score:5, Funny)
The hotter the environment, the worse the thermal insulation
They run it through New York state to take advantage of the Hillary Cooling Effect.
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Re:Superconductors = almost no heat (Score:5, Insightful)
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Re:Superconductors = almost no heat (Score:5, Insightful)
So yeah, they pretty much set the high bar for NIMBYism.
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Cool! (Score:5, Funny)
Hmmm... (Score:5, Interesting)
Besides economics, another advantage the company is touting is that the cables can prevent fault currents, surges that are caused by grid-scale short circuits. Superconductors have an inherent current-limiting ability in that if the current increases past a certain threshold, they lose their superconducting abilities and become normally resistive, damping the current.
Hmm, interesting, but there's more. simply follow the links in TFA and you'll come to these:
"So there's been a stir over the disclosure that AMSC is under investigation by the office of Representative John Dingell, a Democratic congressman from Michigan, one of the most influential U.S. legislators, and an aggressive inquisitor."
"The incident that aroused Dingell's suspicions was the award in 2006 by the U.S. Department of Homeland Security of a multi-million dollar no-bid contract to AMSC to develop and test what it's calling Secure Super Grids in New York City. Working with the local utility Consolidated Edison Co., AMSC plans to develop and install superconducting cables that would connect substations in a much tighter mesh, so that if stations or feeder cables fail, power can be instantly rerouted. Feeder cable failures were implicated in the 1999 and 2006 New York City neighborhood blackouts."
Wow, I didn't know the DHS was responsible for awarding no-bid contracts to energy interests. There ain't no business like no-bidness!
Wow, !vaporware? (Score:5, Insightful)
With the influx of superconducting [slashdot.org] articles [slashdot.org] I got a pretty good feel of "hight temperature" superconducting being vaporware. It's cool that we're seeing real world applications now. TFA even tries to trick you into not believing the summary by saying they were "commissioned", but if I read correctly they mean "was put on the power grid" by commissioned, not "was approved to be built."
Re:Wow, !vaporware? (Score:5, Funny)
It's cool that we're seeing real world applications now.
Superconducters are way cool man.
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Re:Wow, !vaporware? (Score:4, Interesting)
You might want to ask anyone who's ever been in a MRI why the dang thing works at all without it's superconducting super magnets.
According to Wikipedia [wikipedia.org] and your information, MRIs generally use Liquid helium to cool things down to 4K. That's not a high temperature even in the superconductor world.
oh hey, and what about the maglev train in japan, or various ones in germany?? do you honestly think that doing magleg based on normal electromagnets would be energy efficient?
Only one major Maglev line [wikipedia.org], the JR-Maglev, uses high temperature superconductors. JR-Maglev [wikipedia.org] is not commercial; it's just research. Currently, there are two major commercial Maglevs [wikipedia.org], neither of which use high temperature superconductors (let alone any superconducting at all).
These are the reasons I felt that high temperature superconducting is vaporware. It gets a lot of research and demos, but not much real world application. The Japan demo maglev is close, but it was never put in large scale or commercial use. The power grid in TFA seems to be one of the first mass commercial uses of superconducting used. YMMV, someone point out my fail if there have been more uses of high temperature superconductivity in the public space.
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Saving Energy (Score:5, Interesting)
Maybe the US will now leapfrog from an antiquated power distribution system to the most advanced in the world. Maybe. One positive aspect of this is the reduction of energy loss due to the superconductivity. This may also allow long distance lines to be run (even though the cooling will be a problem) which might help balance out the grid when needed.
According to Wikipedia, super conducting cables will use roughly half the energy saved for cooling, but since losses are around 7%, that's still a rather high amount of energy saved.
Re:Possible new 'Terrorism' target? (Score:5, Interesting)
There are many, many ways to build a system to manage loss of coolant, nuclear reactor scrambles being obvious extreme versions. Some of these approaches could be used in a case like this. But we're dealing with Con Ed here, the guys who neglected maintenance such that we ended up having three major blackouts in ten years. So I'm not optimistic. The only thing that we should remember is that at least in theory such problems are somewhat addressable, not least by just the kind of rerouting that this system is supposed to make much easier and faster.
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Re:Possible new 'Terrorism' target? (Score:4, Interesting)
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Re:Possible new 'Terrorism' target? (Score:4, Funny)
The Germans arrested him early in 1942, but let him go for lack of evidence.
That's where they nazis lost it. They should have just rounded up all suspects and put them in a freedom camp or something.
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Re:Possible new 'Terrorism' target? (Score:5, Insightful)
I wish that was funny and not depressing.
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Re:Possible new 'Terrorism' target? (Score:4, Informative)
Of course, a terrorist could blow up any sort of power line with a big enough bomb, but so what - there are far higher-value targets.
Aside from bombs, a coolant leak would be easily stopped in the short term by a water jacket. Do you know how you insulate liquid helium pipes in a lab? You pump liquid helium through them, and a 4 inch thick layer of ice forms in a few minutes, insulating the pipes just fine. At higher temperatures you'd want to provide the water, but I'd bet liquid nitrogen escaping through a layer of water would self-seal very quickly.
Lightning strikes are a problem for all buried power cables, but it's a well-solved engineering problem.
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Re:Possible new 'Terrorism' target? (Score:5, Informative)
Underground power cables are struck by lightning amazingly often - I think more often than high-tension lines. Lighting strikes originate quite deep - given they cross 8 km of air gap, several meters of damp earth should come as no surprise.
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Re:reliability ? (Score:4, Informative)
You might be surprised how little different it would be to have power lines running superconducting in parts of NYC. With the vastly complex infrastructure already in place, doing these lines might not be all that big a deal in some ways.
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Re:reliability ? (Score:5, Informative)
One of the characteristic sights on New York City streets is big tanks of liquid nitrogen standing on the sidewalk, steaming away, with lines running from them down a manhole. Why? Because, iirc, many of the telephone company switching systems already run supercooled and when a repair needs to be done they need supplementary chilling.
Those nitrogen tanks are used by Verizon to pressurize underground telephone cables and keep moisture out:
http://gothamist.com/2008/01/31/nitrogen_tanks.php [gothamist.com]
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Re:OK - 150x capacity, BUT: (Score:4, Interesting)
In a standard copper line the value is zero: we don't cool them
Conventional underground transmission lines are oil cooled. Superconducting transmission lines have almost zero resistance and should require less cooling once they reach working temperature.
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Re:Forget wires (Score:5, Insightful)
This is only a 150 metre prototype, but if the technology scales then it will have a major effect on the economics of power distribution.
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