North American Electric Reliability Corporation - Origins of NERC

Origins of NERC

Early electric power systems, such as those installed by George Westinghouse and Thomas Edison, prior to the start of the 20th century were isolated central stations which served small pockets of customers independently of each other. As some of these power systems grew to cover larger geographic areas, it became possible to connect previously isolated systems. This allowed neighboring systems to share generation and voltage stability resources, providing mutual benefit to each side. However, tying power systems together with these early interconnections also introduced the risk that a single significant disturbance could collapse all of the systems tied to the interconnection. Generally it was decided that the benefits outweighed the risks, and by 1915 interconnections began to flourish and grow in size. By the end of the 1960s there were virtually no isolated power systems remaining in the lower forty-eight states and southern Canada; practically all power companies were attached to large interconnections.

In 1962, when the Eastern Interconnection was established in its current form, The Interconnected Systems Group (composed of Southern and Midwestern utility companies), the PJM Interconnection, and the Canada-United States Eastern Interconnection (CANUSE) formed the Interconnection Coordination Committee to recommend an informal operations structure, which led to the formation of the North American Power Systems Interconnection Committee (NAPSIC). NAPSIC eventually grew to also include the Texas Interconnection and most of the companies in what is today the Western Electricity Coordinating Council (WECC), operating within the Western Interconnection.

On November 9, 1965, a relatively minor system disturbance triggered a power system protection component that was not properly configured. The interconnection was operating near peak capacity due to the extreme cold weather and high heating demand, and was therefore more vulnerable than usual. The small initial outage quickly cascaded into the Northeast Blackout of 1965. This disturbance revealed the extent that interconnections had evolved without adequate high-level planning and operating oversight to try to prevent such events, and that interconnected power systems frequently had varying operating standards and procedures developed somewhat independently by each member on the interconnection. Restoration efforts were also partially hampered due to the lack of common practices and coordination procedures. Furthermore, power system protection schemes were often designed with only a local power system's design in mind, meaning that they might misoperate in response to protection schemes activating in neighboring systems. This disturbance revealed the necessity to develop common operating and protection standards as well as plans to effectively coordinate power system restoration efforts.

The Electric Reliability Act of 1967, passed due to the political pressure and fallout from the 1965 blackout, was a significant turning point in the arena of electric reliability in North America. Initially, ten regional reliability councils were created by groups of interconnected power systems, which collectively covered the entire footprints of the major North American interconnections, and NERC was then formed as a more formalized successor to NAPSIC to spearhead reliability efforts and assist the regional councils by developing common operating policies and procedures as well as training resources and requirements.

Although significant disturbances continued to occasionally occur, such as the New York City blackout of 1977, NERC undoubtedly played a significant role in minimizing the impact and frequency of these events. It is difficult to quantify this success because it is impossible to know how many disturbances were prevented by the influence of NERC and the reliability councils.