What would happen if an energy storage device failed?

[bk78]

A more interesting example would be a rupture of the superconductor because of mechanical stress. But things are a bit more complicated. First, the surrounding matrix will conduct the current. It's resistance is small, but it increases with temperature. Thermal conductivity is small compared to the power generated locally. Of course, the matrix could break as well.
Imagine a ring of a superconductor close another such ring. Superconductors "freeze" the magnetic field at their surface. If one ring fails, the rsulting spark gap is equivalent to a voltage source that changes the rings magnetic field. This change will induce current in the second ring so that the magnetic field stays about the same. If the second ring is made of copper instead, it's resistance then will slowly decrease the current and thus the magnetic field will be transformed in heat, evenly dispersed over the ring. This works less well for a really large energy storage device, because a copper ring would have a higher resistance and be quite costly. So what happens depends a lot on the design, are there coils close to it, what is the casing made of etc.. I am sure, for an ITER like machine you could design the magnets in a safe way so that any disruption from a "terrorist" needs more energy than what is released from the magnets.

I realized i wrote that an energy storage device could hold 10 TWh, which is nonsense of course - I apologize.
Studies were made for a 10 GWh device, though.
http://hal.archives-ouvertes.fr/docs/00 ... 5C1117.pdf

[KitemanSA]

I realized i wrote that an energy storage device could hold 10 TWh, which is nonsense of course - I apologize.
Studies were made for a 10 GWh device, though.
http://hal.archives-ouvertes.fr/docs/00 ... 5C1117.pdf

Ok, we are down to ~7.2ktonnes of HE. That much det cord would take only 4 days to explode, not 11 years.

[Joseph Chikva]

Ok, we are down to ~7.2ktonnes of HE.

Which also corresponds to 1kt of butter.

[Joseph Chikva]

I realized i wrote that an energy storage device could hold 10 TWh, which is nonsense of course - I apologize.
Studies were made for a 10 GWh device, though.
http://hal.archives-ouvertes.fr/docs/00 ... 5C1117.pdf

Very interesting but at today's prices on superconductors extremely impractical. As such energy storage should be built for improving duty factor of power plants. And their construction cost should be on orders on magnitude lower than cost of power plants. In the contrary case their construction does not make sense.
But from technical side of view very interesting. Thanks.

Also I would like to say that for short confinement time I do not see expediency of using superconductors in fusion reactors. As supercunductors do not provide lower mass, do not provide stronger field, superconductors are moch more critical to neutron flux and in case of proper design conventionally conductictive magnets power consumption on ohmic heating is comparable and even on order on magnitude lower than consumption on filling of certain volume with mag field.
Present days cost of supercunductors on at least two orders of magnitude higher than even copper-silver alloy's cost (Cu-0.1%Ag).
Etc.

[GIThruster]

Also I would like to say that for short confinement time I do not see expediency of using superconductors in fusion reactors. As supercunductors do not provide lower mass, do not provide stronger field, and in case of proper design conventionally conductictive magnets power consumption on ohmic heating is comparable and even on order on magnitude lower than consumption on filling of certain volume with mag field.
Present days cost of supercunductors on at least two orders of magnitude higher than even copper-silver alloy's cost (Cu-0.1%Ag).
Etc.

Are you sure you have current data on this generation of superconducting tapes? It is my understanding, the newest tapes all have much higher power density than anything else, which is why the worlds most powerful magnets are made from it, with about 150 times the power of similar copper wire by volume. They certainly do provide much lower mass as well, as is demonstrated with the Navy motors, and the prices have fallen hugely the last few years, which is what has made it commercially viable to put in many mile lengths of SC cabling in places like Japan and NY.

Here's something current from Superpower, who's tape has interested me for years:

http://www.superpower-inc.com/system/fi ... celona.pdf

Likewise, the latest 36.5 MW superconducting motor made for the US Navy is about 1/3 the mass and 1/2 the volume of the copper motor it replaces, is much more efficient and generates much less heat, which in some applications matters a great deal.

[Joseph Chikva]

Are you sure you have current data on this generation of superconducting tapes? It is my understanding, the newest tapes all have much higher power density than anything else, which is why the worlds most powerful magnets are made from it, with about 150 times the power of similar copper wire by volume. They certainly do provide much lower mass as well, as is demonstrated with the Navy motors, and the prices have fallen hugely the last few years, which is what has made it commercially viable to put in many mile lengths of SC cabling in places like Japan and NY.

Here's something current from Superpower, who's tape has interested me for years:

http://www.superpower-inc.com/system/fi ... celona.pdf

Likewise, the latest 36.5 MW superconducting motor made for the US Navy is about 1/3 the mass and 1/2 the volume of the copper motor it replaces, is much more efficient and generates much less heat, which in some applications matters a great deal.

"Latest data" may change every day. Mass of every type of superconducting tape/filament is only a little fraction of whole SC cable. I never heard about limitation of field (near conductor) higher than 25T. Copper's field limitation is only in strength of copper metal and if I remember correctly not less 40T.
From myself I have calculated several options magnets for my fusion proposal. And the picture is the following: for creation of magnetic field with energy content 1GJ we need about 200t of copper square shape hollow conductor (11000 m). Magnet coil runs at LN2 temperature (77K). Power consumption of ohmic heating about 20MW. So, two commercially available homopolar generators 1GJ http://www.utexas.edu/research/cem/IEEE ... ations.pdf powering each coil are enough for keeping that field for about 50s.
These coils provide stronger mag field than ITER's coil and has almost 2 times less mass. And these are real numbers.
Today's price of 1 t of copper on London Metal Exchange is about 7500 USD. So, we should wait hollow copper conductor's price about 10000 USD/t. 200t - 2 million USD.
Can you say the price of ITER's toroidal coil weighing 365 t and consistin SC cable?
Usage of what cooling system is more attractive by cost: liquid nitrogen or liquid helium?

[GIThruster]

Are you sure you have current data on this generation of superconducting tapes? It is my understanding, the newest tapes all have much higher power density than anything else, which is why the worlds most powerful magnets are made from it, with about 150 times the power of similar copper wire by volume. They certainly do provide much lower mass as well, as is demonstrated with the Navy motors, and the prices have fallen hugely the last few years, which is what has made it commercially viable to put in many mile lengths of SC cabling in places like Japan and NY.

Here's something current from Superpower, who's tape has interested me for years:

http://www.superpower-inc.com/system/fi ... celona.pdf

Likewise, the latest 36.5 MW superconducting motor made for the US Navy is about 1/3 the mass and 1/2 the volume of the copper motor it replaces, is much more efficient and generates much less heat, which in some applications matters a great deal.

"Latest data" may change every day. Mass of every type of superconducting tape/filament is only a little fraction of whole SC cable. I never heard about limitation of field (near conductor) higher than 25T. Copper's field limitation is only in strength of copper metal and if I remember correctly not less 40T.
From myself I have calculated several options magnets for my fusion proposal. And the picture is the following: for creation of magnetic field with energy content 1GJ we need about 200t of copper square shape hollow conductor (11000 m). Magnet coil runs at LN2 temperature (77K). Power consumption of ohmic heating about 20MW. So, two commercially available homopolar generators 1GJ http://www.utexas.edu/research/cem/IEEE ... ations.pdf powering each coil are enough for keeping that field for about 50s.
These coils provide stronger mag field than ITER's coil and has almost 2 times less mass. And these are real numbers.
Today's price of 1 t of copper on London Metal Exchange is about 7500 USD. So, we should wait hollow copper conductor's price about 10000 USD/t. 200t - 2 million USD.
Can you say the price of ITER's toroidal coil weighing 365 t and consistin SC cable?
Usage of what cooling system is more attractive by cost: liquid nitrogen or liquid helium?

Those are not real world numbers. The price of raw copper is not the price of wire or bar stock, and copper cannot take 40 Tesla. It would come apart. I think if you want to be using 40T fields for anyhting, be it energy storage or a reactor, you'll want HTSC, which does operate at 77k and does carry much higher currents, even when twisted and shielded, which is not always necessary.

I suggest you look at the work here. There's no chance you'll be getting the fields you're considering from copper. All the world's records the last decade or so have been done with HTSC.

http://www.physorg.com/news/2011-06-wor ... ields.html

"At 25 teslas, the copper would be torn apart," Joachim Wosnitza describes a potential scenario of this conflict between the magnetic field and the metal.

[Joseph Chikva]

The price of raw copper is not the price of wire or bar stock, and copper cannot take 40 Tesla.

You are wrong saying that more powerful magnets made of SC. More powerful magnets are resistive or hybrid (outer coils are superconducting and inner resistive).
Even if you have high-temperature (let's say 77K) superconductor its critical field in which it losses superconductivity is too low and again you are forced run the magnet at lower temperatures. Normal operating temperature of ITER's coils 5K.
My purpose is not to reach 40T but I have calculated normaly conductive magnet coils similar to ITER's toroidal coil and received such data: 200t vs 365t, 14T vs. 5.7T, etc.
Take a look on following:

Largest Bitter magnet
As of 2011 the National High Magnetic Field Laboratory in Tallahassee, Florida, USA, houses the current world's largest resistive magnet. This system has a maximum output of 36.2 teslas and consists of hundreds of separate Bitter plates. The system consumes 19.6 megawatts of electric power and requires about 139 litres of water pumped through it per second for cooling.

National High Magnetic Field Laboratory

The premier magnet system at the Magnet Lab is the hybrid magnet, and this is a combination of two similar ways of making a magnetic field. We have the superconducting technology, or superconducting wire, that uses very little power, but has a limit on how high a magnetic field we can have. The limit is where the wire stops becoming a superconductor and in fact becomes a rather bad conductor.
So to get to ever higher fields, we use resistive magnets,....

Now, please, teach me which newest superconducting material provides field up to 100 Tesla?
And normally conductive single turn magnets provide such strong field in pulse mode. And even high but with destruction. As material strength limitation here plays role.

[GIThruster]

Now, please, teach me which newest superconducting material provides field up to 100 Tesla?

The magnets they've been describing with these enormous fields the last few years are "hybrid" magnets that are 50T from YBCO tape + another 40T from copper that has been surrounded by a "corset" that thwarts explosive decomposition. Still, these are short pulses only. For regular sustained fields around 25T, I think the only magnet ever used is YBCO tape, both from American Superconductor and SuperpowerInc. Last I compared the two, Superpower was producing much higher power densities. In fact I sent some NASA friends to Superpower back in 2007 because they were working with the other stuff at Marshall and it was not working out for them--was both too low power and too low bend radius (how small a circle it can be bent in.) Both those qualities have increased significantly again, since 2007.

Also note, that all the ultra-high power density motors, generators, transformers, MRI, f-MRI, NMR, etc. being designed these days, are with YBCO tapes. The price is going to continue to drop as applications drive manufacture of these tapes by the mile.

Another reason to consider YBCO is the inductor winding layers will be far fewer, and theres parasitic issues with using multiple layers. You might avoid some of this with YBCO.

I haven't read far back in the thread. What is it you're designing?

[Joseph Chikva]

The magnets they've been describing with these enormous fields the last few years are "hybrid" magnets that are 50T from YBCO tape + another 40T from copper that has been surrounded by a "corset" that thwarts explosive decomposition. Still, these are short pulses only.

Wrong. At least 36.2T Bitter magnet is long running.

[Joseph Chikva]

What is it you're designing?

Fusion reactor

[Joseph Chikva]

I think the only magnet ever used is YBCO tape, both from American Superconductor and SuperpowerInc.

You are narrowing the searching area of superconductors suppliers. At least ITER is equipped with Chinese wire.

[KitemanSA]

Ok, we are down to ~7.2ktonnes of HE.

Which also corresponds to 1kt of butter.

maybe if disolved into 6.2ktonnes of saltpeter!

[mdeminico]

So you are on the kaboom side. Anyone else?

That's what my point was.

Worst case, if someone blows the whole gig simultaneously, and all the rings become shattered instantly... boom?

Now the likelihood of that happening is probably low, but still. If it happens over a matter of microseconds, big boom. If it happens over the course of 5 seconds, big heat in one area.

Given my response above, even if the 7.2megatonnes equivalent of high explosive takes 5 second to go off, STILL no boom?

That's the energy equivalent of a million gallons of gasoline.

We burn through that roughly every minute in the world.

Even if a million barrels of gasoline in one spot all cooked off (burned off) at its natural rate, it would just make a crapton of heat.

If it was all spread out with sufficient oxidizers so that it burned in 5 seconds, yeah it'd be a big freaking boom. MOAB size and then some.

[mdeminico]

10TWHr of energy if a terrorist circumvented the

There is no such thing as a 10 TWHr energy storage superconductor, or capacitor....

That's not to say there never will be. Why not talk hypothetical.

And how this managed to stay in the "news" section I have no clue...