APPLICATION OF HIGH-T-C SUPERCONDUCTORS IN ALUMINUM ELECTROLYSIS PLANTS

The electric power system in an aluminum plant has several features that may advocate use of superconducting technology: high power, low voltage, system compactness, direct current, and substantial conductor cost and losses per meter. Two case studies where the cost of conventional bus-bar conductors is compared with the predicted cost of a future nitrogen-cooled high-amperage superconductor based on Ag/BSCCO tapes are carried out. To be an attractive alternative the investment and capitalized operational costs of a superconducting line should not exceed USD 70 per meter per kiloampere rating. Simplified estimates of cost and properties of a superconducting cable show that these requirements are very hard to satisfy, even if long lengths of Ag/BSCCO tapes with operating current densities as high as 50 kA/cm(2) become available.