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romanr writes:
"Copper oxides, also known as cuprates, are the most promising materials for superconductivity. Today, cuprates can be superconductive at temperatures as high as -150 °C. But for many years scientists wondered why they lose superconductivity when concentration of electrons drops below certain level. Most scientist thought that the cuprates gradually became insulators.
Scientists from Université de Sherbrooke discovered that the loss of superconductivity is because of a sudden appearance of a distinct electronic phase in the material that enters into competition with the superconductivity and weakens it. It means, that higher temperature superconductors will be possible if we can get rid of the competing phase. This new approach opens a way to get an ambient temperature superconductivity."
(Score: 5, Insightful) by EventH0rizon on Monday February 17 2014, @07:44PM
Very cool.
I'm keen to see this near room temperature superconductivity kick on, so that we can use coils of the stuff to store electricity almost indefinitely [wikipedia.org].
(Score: 5, Interesting) by ls671 on Monday February 17 2014, @08:03PM
Albeit not "indefinitely", flywheels are good to store energy. Very good to store energy when you need a burst but not limited to that use case. The type of burst you need if you want to create a Frankenstein. Then, no need to wait for lightning.
Find a way to completely eliminate friction and you get "indefinitely".
They even use that principle in formula 1 race cars to get something similar to a nitrous oxide effect.
https://en.wikipedia.org/wiki/Flywheel_energy_stor age#Motor_sports [wikipedia.org]
Everything I write is lies, including this sentence.
(Score: 5, Interesting) by Anonymous Coward on Monday February 17 2014, @08:06PM
To be fair, I think it was only Williams who used a flywheel and they ended up giving up on it and swapping to a battery-based system, but the point remains that a Formula One team, who employ some of the best engineers in the world, let alone in motorsports, spent a year or more experimenting with a flywheel-based energy recovery system, including development along with testing and the races they used it in -- which says quite a bit.
(Score: 3, Interesting) by TheRaven on Tuesday February 18 2014, @04:49AM
sudo mod me up
(Score: 1) by ls671 on Wednesday February 19 2014, @07:58PM
Yep, catastrophic failure can be well, pretty catastrophic, especially with those type of flywheels.
Everything I write is lies, including this sentence.
(Score: 5, Insightful) by EventH0rizon on Monday February 17 2014, @08:14PM
Actually, the promise is indefinitely.
From the linked article: "Once the superconducting coil is charged, the current will not decay and the magnetic energy can be stored indefinitely".
It's my understanding that there is no friction to speak of in a superconducting magnetic coil. They were enthusing about the possibilities in Scientific American a few years back.
As usual though, this technology is probably "Just 5 or 10 years away" ;-)
(Score: 1) by mhajicek on Monday February 17 2014, @11:07PM
I think the intense magnetic field would tend to act on nearby objects, blessing off energy. Am I wrong?
(Score: 3, Informative) by edIII on Monday February 17 2014, @11:24PM
According to a Wikipedia article linked in another post this technology exists right now. It's just very expensive and only used in very specific use cases that can justify the cost.
(Score: 2, Interesting) by ls671 on Monday February 17 2014, @08:45PM
> Find a way to completely eliminate friction and you get "indefinitely".
Makes me think: Planet Earth is a giant flywheel that tends to conserve its rotational energy indefinitely.
Since there is no attach point like a shaft, no friction there. Since it is in a vacuum no air friction either.
Pretty efficient mean of conserving energy isn't it?
Everything I write is lies, including this sentence.
(Score: 5, Funny) by romanr on Monday February 17 2014, @09:04PM
The tidal power stations extract this energy! Greenpeace beware, our planet is going to stop rotating, we should do something about it!
(Score: 3, Insightful) by Fluffeh on Monday February 17 2014, @09:38PM
Not quite though. The moon is slowing us down through the tides, every little thing that hits the electromagnetic field around the earth is introducing a new variable. Although it might seem simplistic to say that there is no interaction with the earth rotating in the "void of space" it's just not quite that way. Even meteors and meteoric dust make up TONS of the stuff each and every single day (estimates vary from merely a few tons to a few hundred tons - but either way it is TONS).
Also, think about all the energy required to power our own electromagnetic field. Sloshing all that iron about like a giant dynamo, having the field encounter constant barrage from solar wind, particles and the like. It takes a toll - just look at poor Mars. Had it, lost it. Planets aren't floating in a perfect void.
(Score: 3, Informative) by romanr on Monday February 17 2014, @08:53PM
Flywheels are problematic energy containers. Although it is true, that certain flywheels can have energy density over 400 Wh/kg (Li-ion have ~200 Wh/kg) there is a momentum that doesn't the flywheel to be handled very easily (this can be mitigated by having another flywheel with opposite momentum though). Another thing is, that they have to rotate with as little friction as possible. Mechanical bearings lose the stored energy in matter of hours and magnetic bearings/high vacuum solution is quite expensive. I perceive flywheels more like mechanical capacitors and not mechanical batteries.
(Score: 1) by sfm on Tuesday February 18 2014, @10:50AM
Flywheels have additional downsides:
Need to be in a vacuum to reduce air friction
Need special materials to achieve energy density near Li-batteries
Special containment "case" is required, both for holding a vacuum and in the event of catastrophic failure
Also, there are non-trivial engineering concerns
Magnetic bearings exist, but they tend to be expensive
Any movement in the axis of rotation causes Coriolis force. For a vertical flywheel, simply the rotation of the earth produces a force depending on latitude
All of these problems have technical solutions and flywheels are a viable technology. Unfortunately, it is hard pressed to compete economically with other forms of energy storage in all but a few special cases.