[vissin]

Superconductors is a topic that really caught my interest every since I bought an old Science in USSR Issue from a raddi-wala that discussed high temperature superconductivity. The temperature that you have mentioned MaRo is very near absolute zero and around that temperature almost anything would turn into a superconductor. The so called high-temperature superconductors I speak of too work at much less than zero degree and is not very practical as of today out of the controlled environment of labs.

As for law of conservation of energy as The_Big_K said, it is not defied since there is neither generation nor consumption of energy in a superconductor that carries current. A superconductor can only be used to store current (there are many other innovative uses of it other than this. But I speak in context of this thread). If you load it, connecting to laptop for instance, the energy will gradually be destroyed (depending on the nature of the resultant circuitry).

Alas! for fading memories and for the lack of time to refresh it... much of a man's passion drains out in due time.