Superconductors race with silver

Electric power losses in heavy-duty motors caused by resistance in wires is a major problem for utility companies and consumers. These losses amount to nearly 60% of total power consumption and require motors to use even more fossil fuels to produce the same amount of electricity, which means higher costs.

Silver-sheathed metal oxides pose an opportunity to reduce such losses considerably. Industrial electric motors operating from 125 to more than 10,000 h.p. consume more than one-quarter of all the electricity produced in the U.S., according to the U.S. Dept. of Energy. Electric motors consume 58% of all the electricity generated in the U.S. Large motors such as those used in plants and mills waste a staggering 20 billion kilowatt-hours annually simply because of the resistance in the wire coils required to operate them. The high-temperature superconducting (HTS) wire manufactured by American Superconductor is sheathed in silver tubes, which are then drawn down to one-sixteenth the width of a human hair. A bundle of these is rolled together and crushed into tape form. The process is designed to keep as much of the superconducting oxides in contact with as much silver as possible. Studies show that the largest amount of electric current flows in those superconducting oxides with direct contact with silver.

The market for industrial motors of 1,000 h.p. or higher is currently US$1.3 billion per year worldwide and expected to double in 10 years. Nearly half of that energy is used by motors that could be converted with HTS components. The demand for superconductors will escalate and is expected to exceed $8 billion annually in the next few years, providing a substantial market for silver.

— The preceding is an excerpt from Silver News, published by the Washington, D.C.-based Silver Institute.