The world’s first in-grid superconducting power cable has gone online in Albany, New York. As mentioned in the August 11, 2006 issue, with more details here, the 350-m underground cable—a demonstration of high-temperature superconducting (HTS) applications to improve electric power transmission and distribution—is operating at 34.5 kV, with a nominal current carrying capacity of 800 A. The cable—developed under the direction of SuperPower, Inc., Schedectady, NY, with partners Sumitomo Electric Industries Ltd. of Osaka, Japan, and BOC of Murray Hill, New Jersey, one of the world’s largest suppliers of industrial gasses —links the Riverside and Menands substations of the North Albany Service Center of National Grid. BOC is responsible for the cryogenic refrigeration system and remote operating center.
The system at the Albany cable project currently uses first-generation HTS wire, but in a later phase, scheduled in about a year, a portion of the system will be replaced with cable using second-generation conductor to further demonstrate its viability. The second-generation HTS conductor, developed by SuperPower, is considered more cost-efficient and commercially viable than first-generation HTS.
“Use of HTS technology in electric power transmission and distribution has the potential for enormous impact on consumers and the utility industry,” said Philip J. Pellegrino, president of SuperPower. “Congestion on our electrical highways has become a major problem. Not only does inefficiency in the current system cost consumers billions of dollars a year, it also threatens the overall reliability of our power delivery network. HTS cable technology enables transmission and distribution of power through much smaller cables than comparably rated conventional copper conduits—plus HTS technology is safer and more environmentally friendly. All of this is especially important in congested urban areas.”

The cable system uses first-generation BSCCO-based HTS wire and will be in operation for about a year. At the same time the team will work on the project's second phase, consisting of a 30-meter section of cable using more than six miles of SuperPower's second-generation YBCO-based HTS wire, which is expected to be substantially less expensive to manufacture. That will replace a segment in the existing cable, which is expected to further improve the performance of the cable, ultimately reduce the cost of the system and improve prospects for commercialization.

“A growing economy depends on reliable and efficient electricity delivery,” said Ed Garcia, vice president, PGS Ventures, BOC. “One HTS cable can deliver three to five times more power than a conventional cable. This means utilities can accommodate demand increases without having to add multiple distribution lines. With the U.S. Department of Energy projecting world electricity demand to grow at an average rate of 2.6 percent per year, this startup is particularly timely as we work to develop new solutions for our aging energy infrastructure.”

“Since work on the $26 million HTS cable project began nearly three years ago, the technology behind the HTS system has been tested extensively, ensuring it can withstand real-world rigors and demands, such as ground faults and trips”, Garcia said. To ensure reliability, BOC is monitoring the HTS cable system from its Remote Operating Center in Bethlehem, PA. Real-time indicators at the center allow operators to make necessary adjustments to the cryogenic system to keep the cable system running.