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: 3, Informative) by romanr on Tuesday February 18 2014, @12:53AM
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, @02:50PM
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.