Advances in high temperature superconductors hint at future for high-efficiency electricity

12/21/2013 - 00:00

The coexistence of two opposing phenomena might be the secret to understanding the enduring mystery in physics of how materials heralded as the future of powering our homes and communities actually work, according to Princeton University-led research. Such insight could help spur the further development of high-efficiency electric-power delivery.

Published in the journal Science, the findings provide a substantial clue for unraveling the inner workings of high-temperature superconductors (HTS) based on compounds containing copper and oxygen, or copper oxides. Copper-oxide high-temperature superconductors are prized as a material for making power lines because of their ability to conduct electricity with no resistance. It's been shown that the material can be used to deliver electrical power like ordinary transmission lines, but with no loss of energy. In addition, typical superconductors need extremely low temperatures of roughly -243 degrees Celsius (-405 degrees Fahrenheit) to exhibit this 100-percent efficiency. A copper oxide HTS, however, can reach this level of efficiency at a comparatively toasty -135 degrees Celsius (-211 degrees Fahrenheit), which is achievable using liquid nitrogen.

Copper oxides are the linchpin of the world's first superconducting electrical line, the 600-meter (1,970-foot) cable installed on Long Island in 2008 as the Holbrook Superconductor Project funded by the U.S. Department of Energy. The cable is chilled with about 49,000 liters (13,000 gallons) of liquid nitrogen. Another 3 million meters (1,860 miles) of superconducting cables are bound for a power grid in South Korea.