By October 2007, a second-generation superconducting cable will be conduiting electrons along a 30-meter stretch connecting hydroelectric stations on the Mohawk and Hudson Rivers to the Grid at National Grid’s North Albany, NY Service Center.
Superconducting cables present negligible electrical resistance compared to copper wire when transmitting alternating current (AC). Small resistance allows transport of Grid electrons over long distances with low line losses. Direct Current (DC) can be transmitted through superconducting wire with virtually zero line loss, but would require a complete paradigm shift in the Grid (from AC to DC) for large-scale implementation.
Operating at 77 Kelvin (liquid nitrogen temperature), this new cable replaces an existing first-generation superconducting conduit whose composition is almost 2/3 silver, making it prohibitively expensive for commercial use. The second-generation wire uses much less silver and is also less brittle than its precursor. The wire’s manufacturer, Superpower, Inc., estimates that by 2011 their superconducting cable products will be equal in price to conventional copper wire. Details of the New York installation were revealed in a recent press release, “Shipment of Completed 30-Meter HTS Cable for Installation Into Albany HTS Cable Project Announced”, and further technical coverage of this installation appeared in a recent Transmission & Distribution World article, “Superconducting Cable Connects the Grid”.