A Commercial Technology Can Help Solve the Reactive Power Capability Problem: Superconducting Magnetic Energy Storage (SMES)

Abstract

The problem of Reactive Power Capability is vital—and it has beenlargely overlooked in the development of competitive generation mar-kets over the past couple of years. One way of solving the problem isthrough Superconducting Magnetic Energy Storage (SMES), which wasdeveloped by American Superconductor. This is one of several reactivepower technologies that have been developed to meet the growingthreat to power transmission—a danger that can affect all users of elec-tricity.SMES (D-SMES) is now a fully commercial technology in use attwo sites in Wisconsin (Wisconsin Public Service Co. and Alliant), withanother system on order for installation in South Africa (Eskom), andanother for metropolitan Houston (Entergy). It basically allows utilitiesto “cache” significant amounts of real power close to customer loads,and inject large amounts of real and reactive power into grids, instanta-neously, simultaneously, and on a distributed basis. Some projects in-creased the delivery capacity into a 200-MW grid by at least 15% (30MW), allowing them to defer line construction by several years at a verylow cost