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High-Temperature Superconductors
Anonymous Coward writes "Seems all those scientists who've spent years tweaking exotic materials at freakily low temperatures to turn them into superconductors should've just looked on the lab shelf. Magnesium diboride superconducts at much higher temperatures than other metallics and could even bust the theoretical max T, says this story at New Scientist. There's more research on the same here but 40K's still pretty cold - when's my laptop gonna run for free?"
Unless you spend more energy cooling the thing than you save in lower transmission loss. I guess we need perfect insulators too.
Firstly, we have several insulation schemes that will work well enough for this purpose. Least exotic: Put a vacuum gap between your cable pipe and a larger pipe around it. Most exotic: Aerogel insulation (they found a cheap method to produce it a few years back).
Secondly, transmission line losses are substantial enough that reducing them would be a Very Profitable Thing.
Thirdly, though, superconducting cables aren't likely to be the way to do it. Most of the transmission losses in the power grid are inductive.
Besides that fact that the materials involved here are "cheap and easy," another interesting aspect to this is that the superconductivity appears to occur through the good 'ol BCS mechanism, which is your grandma's physics (not that wacky stuff they need to explain the ceramic material transitions).
It's been done. Twice. Slashdot even had articles about the first one and the sequel. The trouble happens when certain semiconductors get too cold to semiconduct. (Remember, conductivity increases with temperature in a semiconductor)
Bugrit! Millenium hand and shrimp!
Liquid nitrogen boils at about 77 degrees Kelvin, to warm to keep this material superconducting. Liquid helium is the next coldest liquid at 4 degrees K.
science is a religion
The first "high-Tc" superconductor was also only around 40 K - the thing was it was a new type of material (an oxide ceramic) that had previously never before been tested; similar to this case, although this time the material seems to be even simpler. With the old-style high-Tc materials it was only a few months before they got the things working above liquid nitrogen; it's possible tweaking this material will do the same thing or even better, you never know. Really exciting!
Energy: time to change the picture.