Breakthrough - superconductor

[harry]

New superconductor found, works at room temperature. Most important discovery of the decade?

[Andy Burns]

"seems to conduct electricity"

"it will not have any immediate practical applications"

[Richard]

So this isn't actually a breakthrough.

[Martin Brown]

However, it needs a pressure of *40,000,000psi* to work.

A feat at present only possible between carefully shaped diamond anvils and a very large hydraulic press. It is a curiosity - nothing more.

[Robin]

a. most rooms - and transmission lines - are a damn site warmer than

287.7 K (c.15C) and

b. that temp. was only achieved with a pressure of 267 gigapascals.

I shall stick to my practice of following no more than one of your links per term.

[Chris Hogg]

A step in the right direction, certainly, but "The superconductor has one serious limitation, however: it survives only under extremely high pressures, approaching those at the centre of Earth, meaning that it will not have any immediate practical applications."

When 'high temperature' superconductors were first discovered, with critical temperatures above that of liquid nitrogen, 77K IIRC, in the late 1980's, great hopes were held out for them, because liquid nitrogen was relatively easy to produce and fairly commonplace, unlike liquid helium which had to be used for earlier superconductors. Transmission cables cooled by liquid nitrogen was at least on the far edge of possibility. But AFAIK not a lot has come of them. One of the main problems was making them into a continuous 'wire', such as would be needed for cables and magnet windings etc. The 'high temperature' superconductors were crystalline materials, and in no way ductile.

The Wiki on superconductors is here

've not ploughed through it.

[Jimk]

At those pressures?

[GB]

Not there yet, but ?If I have seen further, it is by standing on the shoulders of giants.? This is definitely a shoulder.

[Jim GM4 DHJ ...]

thought buses were one man operated these days ....

[The Natural Philosopher]

And in terms of transmission line practicalities and costs it is almost completely irrelevant, anyway.

[Jethro_uk]

Files alongside nuclear fusion articles ...

[The Natural Philosopher]

No it isn't. It's a toenail at best.

The ONLY place we have found superconductors are deal makers is in generating massive magnetic fields were we simply cannot cram enough current into a room temperature copper coil without melting it. And a bigger coil leads to a larger magnetic field.

It is supremely irrelevant to HVDC links where losses can be kept down at sane cost by using a larger conductor or a pair of them.

That's the difference between being an armchair wannabe scientist, and a retired engineer.

The instant question an engineer asks is 'whether it will do more at lower cost and higher reliability?'

superconductors would make no difference to performance really and costs would probably rise.

[Jethro_uk]

Maglev trains would be a practical application too.

[The Natural Philosopher]

Not 'too'. That is fully covered by 'massive magnetic fields'.

But again the small gains in friction of getting rid of steel wheels on steel rails simply isn't worth that much.

High conductivity to total conductivity is not a huge step. semiconductors have meant far more to the world than superconductors

[Jeff Layman]

Possibly.

But it is interesting to compare it with the history of nuclear power. It took only 10 years from its discovery by Rutherford to the first nuclear pile in 1942, even though, according to the Wiki (

) in 1932 Rutherford, Bohr, and Einstein "believed harnessing the power of the atom for practical purposes anytime in the near future was unlikely." No doubt the war and development of an atomic bomb was a huge influence, but it showed how even the most eminent scientists of the time were way out when it came to predicting the future.

I suppose the real question is whether or not a practical RT superconducting power transmission line would be cheaper than the current ones. Is it possible to compare the differences in cost of manufacture, use, maintenance, etc?

[The Natural Philosopher]

The copper cost of an undersea HVDC cable is the smallest part. All the cost is in laying it, in the armouring and the massive insulations needed and in the layers that (seriously) deter shark attack and the like.

And operated at the sorts of levels the cables are, the actual cable losses are probably well below 5% - there are more losses in the inverters and rectifier circuits. So a superconductor cable represents very very little gain at all.

Obviously if it was as cheap and easy to manufacture as copper everyone would use it routinely, but it wouldn't affect the decision to lay the cable or not.

My issue was only with the stupidity of the statement that such a material would make the implementation of a global supergrid *inevitable*.

It's as stupid as the 'renewable energy is free' statement, So too is coal gas, uranium,... God doesn't charge for any of them. Always, what counts is the lifetime cost of the total solution.

[Robin]

Do you dismiss similarly superconducting magnetic energy storage?

[GB]

I used to think that my physics Masters qualified me as a scientist. I'm so, so grateful to you for putting me right.

[Tim Streater]

Well it might qualify you as a scientist. But does it qualify you to do the engineering costings for a project?

[GB]

No. But, it's all hot air at the moment, anyway.