Technology  »   Very-low-impedance superconducting cables and transformers

Such equipment can carry 150 times the electricity of similar-sized copper wire. They could be especially useful in highly congested areas or regions that are capacity constrained but where it is impractical to obtain new rights of way for building new transmission lines.


An Article on recent deployment :

2 July 2008—Last Wednesday, American Superconductor officially commissioned the world's first high-temperature superconductor power-transmission cable system to be used in a commercial power grid. Superconductors can supply lots of energy quickly, efficiently, and unobtrusively. They conduct 150 times the electricity of similarly sized copper wires. However, because of technological difficulties, the commercial development of superconductor power-cable systems has been slow.

The system commissioned last week, part of the Long Island Power Authority's grid and funded by the Department of Energy, consists of three cables operating at 138 kilovolts. It was energized in April 2008 and has the ability to power 300 000 homes when operating at full capacity.

However, there are still some technological hurdles to overcome before superconductors replace the copper wires in our power grids. The main issue is cost. The first-generation cables, now operating successfully on Long Island, are costly, mainly because the wires are coated with silver. Testing has just begun on a second-generation cable coated with copper, which cuts four-fifths of the cost.

Complete Article :

http://spectrum.ieee.org/jul08/6428