Electric utility system applications of fast-acting energy storage as illustrated by SMES

Utility energy storage media can be classified as fast- or slow-acting in reference to command and control response times ranging from milliseconds to less than a minute. World-wide, the generation and delivery of electric power typically relies on less fast-acting energy storage per unit of capacity than may be optimal. The present situation is expected to change as utility planners respond to new demands and begin to recognize that the near-instant availability of stored energy offers many high-value, cost-effective system benefits. This paper summarizes two application studies of superconducting magnetic energy storage (SMES) to illustrate some generation and transmission benefits of fast-acting storage. Emphasis is placed on the performance and economic criteria that can justify utility adoption and use of SMES options. (author) 9 figs., 3 tabs., 15 refs