In 1986, Karl Alexander Müller and Johannes Georg Bednorz, researchers at IBM Research–Zurich, concocted a barium-lanthanum-copper oxide that displayed superconductive properties at 35 K. That's 12 or so kelvins warmer than any other superconductive material known at the time. What made this discovery even more remarkable was that the material was a ceramic, and ceramics normally don't conduct electricity. There had been hints of superconducting ceramics before, but until this time, none of them had shown much promise.
Müller and Bednorz's work triggered a flurry of research around the world. And within a year scientists at the University of Alabama at Huntsville and the University of Houston found a similar ceramic compound that showed superconductivity at temperatures they could attain using liquid nitrogen. Before, all superconductors had required liquid helium—an expensive, hard-to-produce substance—for cooling. Liquid nitrogen, however, can be made from air without that much effort. So the new high-temperature superconductors, in principle, threw the door wide open for all sorts of practical uses, or at least they appeared to.
The discovery of high-temperature superconductors sparked tremendous publicity—which in retrospect is easy to see was hype. Newsweek called it a dream come true. The cover of Time magazine showed a futuristic automobile controlled by superconducting circuits. BusinessWeek declared, "Superconductors! More important than the light bulb and the transistor" on its cover. Many sober scientists and engineers shared this enthusiasm. Among them were Yet-Ming Chiang, David A. Rudman, John B. Vander Sande, and Gregory J. Yurek, the four MIT professors who founded American Superconductor Corp. during this time of feverish excitement over the new high-temperature materials.
Despite all the hoopla, managers at Oxford Instruments, one of the few companies with any real experience using superconductivity at that point, had a dim view of the prospects for the high-temperature ceramics. For the most part, they decided to stick to their former course: working to improve the company's low-temperature niobium-titanium wire and making incremental improvements in its MRI magnets. Oxford Instruments put only a small effort into studying the new high-temperature superconductors.
The management at IGC, which at the time included one of us (Haldar), saw more promise in the new materials and worked hard to see how they could commercialize them for such things as electrical transmission cables, industrial-scale current limiters, energy-storage coils, motors, and generators. American Superconductor, which went public in 1991, did the same.
It took more than a decade to do, but IGC eventually developed a high-temperature superconducting wire and in collaboration with Waukesha Electric Systems, in Wisconsin, built a transformer with it in 1998. In 2000, IGC and Southwire, of Carrollton, Ga., demonstrated a superconducting transmission cable. Soon after, Haldar and his IGC colleagues established a subsidiary, called IGC-SuperPower, to develop and market electrical devices based on high-temperature superconductivity.
In 2001, American Superconductor tested a superconducting cable for the transmission of electrical power at one of Detroit Edison's substations. In 2006, SuperPower connected a 30-meter superconductive power cable to the grid near Albany, N.Y. American Superconductor carried out an even more impressive demonstration of this kind in 2008, when it threw the switch for a 600-meter-long superconducting power cable used by New York's Long Island Power Authority, part of a program funded by the U.S. Department of Energy.
While all these projects were technically successful, they were merely government-sponsored demonstrations; electric utilities are hardly clamoring for such products. The only commercial initiative now slated to use superconducting cables is the proposed Tres Amigas Superstation in New Mexico, an enterprise aimed at tying the eastern, western, and Texas power grids together in one spot. Using superconducting cables would allow the station to transfer massive amounts of power, and because these lines can be relatively short, they wouldn't be prohibitively expensive.
But Tres Amigas is an exception. For the most part, the electric power industry has shown a stunning lack of interest in superconductors, despite the many potential benefits over conventional copper and aluminum wire: three to five times as much capacity within a given conduit size, half the power losses, no need for toxic or flammable insulating materials. With all those advantages, you might well wonder why this technology hasn't taken the electric-power industry by storm over the past two decades.
One reason (other than cost) may stem from the changing nature of electric utilities, which in many countries have lost their former monopoly status. These companies are by and large reluctant to make substantial investments in infrastructure, especially for projects that don't promise a quick return [see "How the Free Market Rocked the Grid," IEEE Spectrum, December 2010]. So the last thing many of them desire is to assume the risk of adopting anything as radical as superconductive cables, generators, or transformers.
It may be that superconductivity just needs time to mature. Plenty of technologies work that way. Perhaps the next generation of wind turbines will sport superconducting generators in their nacelles, an application that American Superconductor is working toward. A better bet in our view, though, is that superconductivity will remain limited to applications like MRI, where it's very difficult to build something any other way.
What will those applications be? A ship that cuts through the waves using superconducting magnetic propulsion instead of propellers? Unlikely: Japanese engineers built such a vessel in 1991, and it's long since been mothballed. An antigravity device that can make living creatures float? Probably not: The 2010 Nobel laureate Andre Geim demonstrated that this could be done in 1997, and it hasn't been put to any real use. A magnetically levitated train that can top 580 kilometers per hour? Japanese engineers built one in 2003; yet few rail systems are giving up on wheels. A supercooled microprocessor that can run at 500 gigahertz? Perhaps: IBM and Georgia Tech captured that speed record in 2007, but it would be hard to make such a setup practical.
We certainly don't know what's ahead. But we suspect that the next big thing for superconductivity, whatever it is, will, like MRI, take the world by surprise.
About the Authors
Pradeep Haldar and Pier Abetti, "Superconductivity's First Century," together have almost a half century of experience with superconductivity. Haldar, an IEEE Senior Member, is a professor of nanoengineering at the University of Albany, of the State University of New York. Abetti, an IEEE Life Fellow and professor of enterprise management at Rensselaer Polytechnic Institute, once had Haldar as a student. Only after Abetti began lecturing about the commercialization of superconductivity did he learn that Haldar had been a director of technology in that very industry. "He made me get up and talk about the whole thing," says Haldar.