Current may flow free and cheap

Ceramic materials that carry electricity at low temperatures with no resistance are showing up in prototype cables, transformers, and other devices. In place of copper-based equipment, superconducting devices offer potentially large energy savings, but at premium prices. Now, an advance in wire making offers promise of lower-cost superconducting wires.

These remarkable ceramic materials are known as high-temperature superconductors because they operate resistancefree at temperatures in the range of 77 kelvins or more, rather than the 20 kelvins or less that conventional superconductors require.