Another Energy Problem: Growing Demand for “Reactive Power” Challenges U.S. Transmission Systems

Abstract

A significant challenge to the transmission providers reported bythe National Electric Reliability Council (NERC) will be to maintainadequate levels of reactive support for the transmission system in theera of open market competition in the U.S. Unlike real power (MW),the reactive component of power (Mvar) cannot be easily transmittedover longer distances and must generally be supplied at the locallevel.Without adequate reactive power support, portions of the electricpower system can be susceptible to potential voltage collapse or insta-bility according to NERC. Sources of reactive power include generators,synchronous condensers, transmission lines, capacitors, and very spe-cialized reactive support devices generally known as static var compen-sators (SVCs).Demand for reactive power is shaped by the size and type of de-mand, power transactions across the transmission system, and the load-ing of transmission facilities. This demand for reactive power is growingnationwide