The Holbrook Superconductor Project is the world's first production

superconducting Superconductivity is a set of physical properties observed in certain materials where electrical resistance vanishes and magnetic flux fields are expelled from the material. Any material exhibiting these properties is a superconductor. Unlike ...

transmission power cable. The lines were commissioned in 2008. The suburban Long Island electrical substation is fed by a 600 meter long tunnel containing approximately 155,000 meters of high-temperature superconductor wire manufactured by

American Superconductor American Superconductor (AMSC) is an American energy technologies company based in Ayer, Massachusetts specializing in the design and manufacture of power systems and superconducting wire. It owns AMSC Windtech in Klagenfurt, Austria. Detroit ...

, installed underground and chilled to superconducting temperature with liquid nitrogen.

Project

The project was funded by the

United States Department of Energy The United States Department of Energy (DOE) is an executive department of the U.S. federal government that oversees U.S. national energy policy and manages the research and development of nuclear power and nuclear weapons in the United Stat ...

, and operates as part of the Long Island Power Authority (LIPA) power grid. The project team comprised American Superconductor, Nexans,

Air Liquide Air Liquide S.A. (; ; literally "liquid air"), is a French multinational company which supplies industrial gases and services to various industries including medical, chemical and electronic manufacturers. Founded in 1902, after Linde it is ...

and LIPA. It broke ground on July 4, 2006, was first energized April 22, 2008, and was commissioned on June 25, 2008.https://digital.library.unt.edu/ark:/67531/metadc842743/m2/1/high_res_d/1046827.pdf Between commissioning and March 2009 refrigeration events impacted normal operation. The superconductor is

bismuth strontium calcium copper oxide Bismuth strontium calcium copper oxide (BSCCO, pronounced ''bisko''), is a type of cuprate superconductor having the generalized chemical formula Bi2 Sr2 Ca''n''−1 Cu''n'' O2''n''+4+''x'', with ''n'' = 2 being the most commonly stud ...

(BSCCO) which superconducts at liquid nitrogen temperatures. Other parts of the system include a liquid nitrogen storage tank, a

Brayton cycle The Brayton cycle is a thermodynamic cycle that describes the operation of certain heat engines that have air or some other gas as their working fluid. The original Brayton engines used a piston compressor and piston expander, but modern gas tu ...

Helium refrigerator, and a number of

cryostat A cryostat (from ''cryo'' meaning cold and ''stat'' meaning stable) is a device used to maintain low cryogenic temperatures of samples or devices mounted within the cryostat. Low temperatures may be maintained within a cryostat by using various r ...

s which manage the transition between cryogenic and

ambient temperature Colloquially, "room temperature" is a range of air temperatures that most people prefer for indoor settings. It feels comfortable to a person when they are wearing typical indoor clothing. Human comfort can extend beyond this range depending on ...

s. The system capacity is 574 MVA with an operating voltage of 138 kV at a maximum current of 2400 A.

References

{{Reflist Superconductivity Electric power transmission systems in the United States Electric power distribution Energy infrastructure on Long Island, New York