BOX 9.1

The Northeast Blackout of August 14, 2003

A modern T&D system could have helped to avoid the circumstances that initiated the August 2003 Northeast blackout. Two major issues contributed to this blackout: first, the operators did not know the system was in trouble; and second, there was poor communication between the utilities operating the transmission lines—First Energy and American Electric Power—and also between these utilities and the ISO responsible for the area (the Midwest Independent System Operator). The U.S.-Canada Power System Outage Task Force (2004) noted that four major factors contributed to the blackout:

  1. Inadequate system understanding,

  2. Inadequate situational awareness,

  3. Inadequate tree trimming,

  4. Inadequate reactive power control diagnostic support.

A modern T&D system could have provided better understanding of the state of the system, better communications, and, ultimately, better controls. Adequate monitoring, communication, and dynamic reactive power support during the initial voltage sag could have helped to prevent lines from overloading, heating up, and sagging excessively. Operators would have been better informed, and online real-time dynamic contingency analysis of potential system collapse would have helped operators stay aware of possible risks and actions to be taken in response. Finally, automatic actions could have been taken to island (isolate) portions of the system and prevent the ultimate cascading event (which spread the localized outage across much of the northeast United States and Canada). The system could also have been restored much more rapidly if a modern grid had been in place.

systems must be modernized—a complex but vital undertaking.6 However, orders for modern transmission technologies remain low, largely because they are perceived to be risky and uneconomic,7 as discussed in more detail later in this chapter. Thus if business continues as usual, investment will focus on new construction to meet peak load growth, which is projected to increase


Modernization is defined here as the deployment of a suite of technologies (described in the coming sections) that will enable the T&D systems to meet a variety of challenges, particularly the seven characteristics (adapted from NETL, 2007d) discussed in more detail in the section titled “A Modern Electric T&D System.”


This view was presented repeatedly to the committee by industry representatives, including those representing Southern California Edison Co., Areva, ABB, and Siemens.

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