An idealized application for superconductors
is to employ them in the transmission of commercial power to cities.
However, due to the high cost and impracticality of cooling miles
of superconducting wire to cryogenic temperatures, this has only happened with short
"test runs".
In May of 2001 some 150,000 residents of Copenhagen, Denmark,
began receiving their electricity through HTS (high-temperature superconducting) material.
That cable was only 30 meters long, but proved adequate for testing purposes.
In the summer of 2001 Pirelli
completed installation of three 400-foot HTS cables for Detroit Edison at the Frisbie Substation capable of delivering 100 million
watts of power. This marked the first time commercial power has been delivered to customers of a US power utility through
superconducting wire. Intermagnetics General has announced that its IGC-SuperPower subsidiary has joined with BOC and
Sumitomo Electric in a $26 million project to install an underground,
HTS power cable in Albany, New York,
in Niagara Mohawk Power Corporation's power grid.
Sumitomo Electric's DI-BSCCO cable was employed in the
first in-grid power cable demonstration project sponsored by the U.S. Department of Energy
and New York Energy Research & Development Authority. After connecting to the grid
successfully on July 2006, the DI-BSCCO cable has been supplying the power to
approximately 70,000 households without any problems. The long-term test will be
completed in the 2007-2008 timeframe.