Superconductors heading for electricity superhighway

A superconductor power transmission cable has been successfully tested by the Long Island Power Authority in New York.
The 138- kV, 574 MVA power link is 600 metres long and is said to be the world’s longest, highest-voltage superconductor in the world. It consists of three high-temperature superconductor (HTS) cable phases running in parallel. This application is also the world’s first superconductor cable system installed in a live grid operating at transmission voltage.
HTS cables can carry up to five times more power than conventional copper cables of similar size. The line tested in Long Island can transmit enough electricity to power 300,000 homes.
The U.S. Department of Energy conducted the demonstration project to test how HTS cables could be become part of a transmission system’s electricity superhighway. The tested system included six outdoor terminations for connecting to Long Island Power’s grid. The superconductor was designed, made and installed by Nexans of Paris, France.
In superconductors, multiple strands of HTS wire are woven into a coaxial configuration and cooled with liquid nitrogen. American Superconductor Corporation produces the HTS wire in the Nexans cables.