Superconducting Power Grid Launches In New York

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.

Comments

I'd contribute funds to that...

[stevedcc]

If I could get my pc on the cooling network..... mmmmmm, 65K. Should be enough for anybody!

Re:I'd contribute funds to that...

[MightyYar]

The article SHOULD have said that the wires were about 1/1000th the diameter of an African male elephant, and carry about 12 Library of Congresses worth of current - for a total of a mind-boggling 23 Senate chambers' worth of hot air.

Cool!

[Plazmid]

I am going to go find a place where these lines aren't underground and see if I can get my neodymium magnets to levitate on it. Maybe even play some superconducting variant of hockey...

Hmmm...

[Ethanol-fueled]

From TFA:

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!

Re:Hmmm...

[R2.0]

I dunno - having John Dingell investigate someone for government fraud is like Typhoid Mary accusing someone of not covering their mouth when they sneeze.

Re:Hmmm...

[duffbeer703]

In regard to projects like this, you have it all wrong. Let's think for a minute.

New York City and its tri-state metro area is the largest in the country, and essentially the world's financial capital. Its arguably one of the most important areas in the country.

For a variety of reasons like NIMBY, the dysfunction of NY state government and rapidly increasing demand, an increasing proportion of the electricity supply is coming from places hundreds of miles away in Upstate NY and Quebec. The geography of NYC and Long Island (and the high cost of land) makes it very difficult to add transmission lines, and makes it relatively easy to attack the existing lines.

So, if a technology like superconducting transmission lines would allow you to increase capacity and better protect these lines by burying them, it seems like a valid security measure to me.

Wow, !vaporware?

[martinw89]

With the influx of superconducting articles 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?

[tttonyyy]

It's cool that we're seeing real world applications now.

Superconducters are way cool man.

Re:Wow, !vaporware?

[martinw89]

IANASCE, but I still can't seem to find any large commercial uses of high temperature superconductivity.

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 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, the JR-Maglev, uses high temperature superconductors. JR-Maglev is not commercial; it's just research. Currently, there are two major commercial Maglevs, 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.

Saving Energy

[dlevitan]

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:Saving Energy

[maxume]

This is a pretty good write up of what is involved in an underground cable:

http://jwz.livejournal.com/94645.html

Wild stuff.

reliability ?

[cats-paw]

To a large extent good old passive wires make for quite a robust system.

However with the addition of all the support equipment necessary for LN2, doesn't this make for a step
backward in terms of reliability ?

Decentralized power production, e.g., solar, still seems like a more worthwhile idea to me.

Re:reliability ?

[RustinHWright]

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.
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.

Re:reliability ?

[ptbarnett]

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

Re:Possible new 'Terrorism' target?

[RustinHWright]

Well, in a perfect world (we can at least hope) lines would be kept a bit below theoretical optimum temperature and surrounded with some high thermal mass cladding within the insulation. That would at least buy some time for the system to get repaired. Since you're dealing with a cylindrical cross-section your surface area to volume ratio is at least as good as it can get to minimize heating.
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.

Re:Possible new 'Terrorism' target?

[FTL]

People have been blowing up conventional electricity pylons for decades. They make great targets because a single tower collapse takes out the whole circuit. Of course we call them 'heroes' not 'terrorists', but the principle is the same: http://query.nytimes.com/gst/fullpage.html?res=9501EFDC1330F935A15757C0A9669C8B63&sec=&spon=

Re:OK - 150x capacity, BUT:

[MichaelSmith]

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.

Re:Possible new 'Terrorism' target?

[lgw]

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.

Superconductors = almost no heat

[DrYak]

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.

Re:Superconductors = almost no heat

[stevedcc]

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.

Re:Superconductors = almost no heat

[Antique Geekmeister]

But they do have impedance (which often confuses people). They also have radiative losses: some electro-magnetic enegy can, and will, couple into nearby objects and be dissipated there.

Re:Superconductors = almost no heat

[hardburn]

Superconductors break down if you put AC through them, so yes. AC might have been the right choice when Tesla was around, but not anymore.

Re:Superconductors = almost no heat

[Karma Bandit]

Actually, in Type-II (high temperature) superconductors there can be a small but finite resistance. From wikipedia:

In a class of superconductors known as Type II superconductors, including all known high-temperature superconductors, an extremely small amount of resistivity appears at temperatures not too far below the nominal superconducting transition when an electrical current is applied in conjunction with a strong magnetic field, which may be caused by the electrical current. This is due to the motion of vortices in the electronic superfluid, which dissipates some of the energy carried by the current. If the current is sufficiently small, the vortices are stationary, and the resistivity vanishes. The resistance due to this effect is tiny compared with that of non-superconducting materials, but must be taken into account in sensitive experiments. However, as the temperature decreases far enough below the nominal superconducting transition, these vortices can become frozen into a disordered but stationary phase known as a "vortex glass". Below this vortex glass transition temperature, the resistance of the material becomes truly zero.

Re:Superconductors = almost no heat

[duffbeer703]

Even if it took alot of energy to cool the lines, these would still make sense in NY. Long Island is like the epicenter of the NIMBY philosophy, so no new power generation has been added for 30-40 years. Most new power is actually transported from the large hydro projects in Quebec. Using the existing power rights of way, 60-75% of each marginal increase in power transmission is lost in transit. So if you send 10 units of electricity from Quebec, 2-4 units will come out on the other end.

Re:Superconductors = almost no heat

[tzanger]

You don't have inductive losses; you have losses due to skin effect -- basically alternating current in a conductor tends to travel along the outer surface of the conductor, rather than through it. The higher the frequency, the less of the conductor is used to actually carry current. All major transmission lines run DC for this very reason (and also to facilitate synchronization of different generation "zones").

Re:Superconductors = almost no heat

[OldMiner]

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. 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.

Re:Superconductors = almost no heat

[bcrowell]

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.
No, there's nothing that keeps superconductors from making external fields. In fact, one of the most common applications of superconductors is as electromagnets.

The GP post is just completely incorrect about all transmission lines being DC. You are right, they're normally AC. However, the reasons they're AC might not apply to superconductors. The reason AC became the standard way to transmit electric power was that AC can be put through a transformer, and with a transformer you can step up the voltage for long-distance transmission, then step it back down again at the end. The higher voltage gives smaller ohmic power losses. With a superconductor, you don't have to worry about ohmic power losses, and that might make it more practical to transmit power using DC. The advantage would be that you'd have no inductive losses. The disadvantage would be that you'd need an inverter at the end in order to convert to AC, since the user's building is full of AC devices. Inverters are not perfectly efficient, and they're also not cheap, so maybe that's worse than just accepting the inductive losses.

Trying to imagine an application where you'd really want to use superconducting power transmission with DC, one that occurs to me is if you have a big photovoltaic farm in Arizona, and you want to send all that energy to Los Angeles. The photovoltaics produce DC, so somewhere, somehow you've got to have an inverter. Maybe you'd put the inverter at the LA end, and avoid inductive losses. But it would be a huge engineering project to lay a trench from Arizona to LA and fill it with liquid nitrogen.

Re:Superconductors = almost no heat

[jpfalc]

I'm from the area (very close to said power plant) so I figured I could clarify on why Long Island is the NIMBY capital of the world:

There are very few rivers and streams on Long Island, and most of them are in located in parks or protected woodlands. This means that almost all the drinking water for LI residents comes from ground water - most of it is contained in large underground aquifers.

Nuclear catastrophes usually involve radioactive material finding its way into the ground - and eventually the groundwater. This is a very unlikely scenario, but if it happened the outcome would be devastating. Houses here tend to be very expensive (compared to other parts of the country) and land values are always on the rise, which makes them a great investment for many residents who plan to sell their houses years down the road, move somewhere cheaper, and live off the difference. Any contamination of the groundwater would make housing values plummet and stay that way for a very, very long time. This is just not a risk that homeowners here are willing to take for a tiny decrease in electricity costs. Whether or not they are well-informed is a different issue.

Add in the fact that shipping in drinking water from anywhere would be very difficult/expensive and a major evacuation of the island could take weeks. Both of these go double for the eastern parts of the island where there are few/no highways/ports. A major hurricane here would put New Orleans to shame.

Re:Possible new 'Terrorism' target?

[lgw]

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.

Re:Possible new 'Terrorism' target?

[megaditto]

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.

Re:Forget wires

[TheRaven64]

I disagree. Large-scale power distribution is pretty much always more efficient. Even if you are talking about solar, then large-scale sun-tracking mirrors focussing on central elements is more efficient than individual scattered cells. The problem, currently, is that you lose a lot of what you gain when you transmit it a long way. If you have superconducting wires then it becomes possible to convert a large part of the Sahara desert into a solar array and supply all of Europe, and do the same with plants in the middle of the US for cities on the edge.

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.

Re:Heat from environment

[MightyYar]

The hotter the environment, the worse the thermal insulation

They run it through New York state to take advantage of the Hillary Cooling Effect.

Re:Possible new 'Terrorism' target?

[Nimey]

I wish that was funny and not depressing.

Re:Heat from environment

[WhoBeDaPlaya]

That's cold.

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Re:Possible new 'Terrorism' target?

[RustinHWright]

Okay, maybe this is a stupid question but I really don't think that it is.
- Liquid nitrogen is cheap. The more of it you need, hence the larger your machinery for making it, the cheaper it gets.
- We're talking about a hundred million dollar system here, just in construction and maintenence costs. Not to mention the billions of dollars worth of services that would depend on it.
- If your insulation is at all effective, the amount of liquid nitrogen required to cool a given stretch of cable is pretty small, since the whole cross-section of cable is something like two centimeters, including part of the cladding.
This being the case, maybe it would be cheaper all around to just keep two or three hundred liters of "extra" liquid nitrogen in tanks connected to the system every mile or so. If the system is leaky, who cares? As long as you're making liquid nitrogen faster than you're leaking it and you are keeping the stuff flowing effectively to the leak, it's just not that big a deal. Keep in mind that at retail prices "two or three hundred liters" is about four hundred bucks worth. Maybe. Relative to the cost and importance of a system like this, a few hundred bucks, even the cost of the equipment to make that liquid nitrogen, is a rounding error.

They can feel the magnetic field?

[GPS Pilot]

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 procedure. Can you cite a source for this information? Thanks