The day the lights went out: The blackout of 2003
By The Associated Press
A power blackout beginning the afternoon of Aug. 14, 2003, cascaded from northeast Ohio to seven other states and parts of Canada, reaching 50 million people. Some of the immediate and long-term effects:
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THE DARK SIDE: Outages of various durations stretched across 9,300 square miles, leaving customers from Michigan to New England with intermittent phone service, no lights and no air conditioning in the summer heat. The blackout shut down more than 100 power plants, forced hospitals and prisons to operate on backup generators, and stranded people in elevators and on roller coasters. It caused transportation chaos as airlines canceled flights and much of New York City was immobilized.
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HIGH AND DRY: Outages were reported along a 145-mile stretch of Lake Erie coastline. That created water shortages for about 1.5 million people near Cleveland, which had no power to pump its water up from Lake Erie.
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TREE TRIMMING: Trees touching higher-voltage transmission lines were partly blamed by blackout investigators, and utilities began trimming vegetation more attentively along such lines. Occasionally it leads to legal disputes with residents protective of their greenery.
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NEW RULES: The tree-trimming is among regulations mandated after the blackout to ensure reliability. The North American Electric Reliability Corp. now sets standards and tracks the performance of the larger grid.
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RAPID RESPONSE: Grid operators now are better trained and use technology that allows them to monitor the system more closely and nearly in real time. Some operators have added new control centers.
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Source: AP research
By The Associated Press
The U.S. electrical grid is a complex system of power plants, transmission lines, and local distribution networks that deliver power to homes and businesses. It comprises three major grids — Eastern, Western and Texas — which are divided into hundreds of smaller sections. A summary of how power flows on the system, who oversees it and what went wrong in the August 2003 blackout:
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GENERATION: The roughly 6,000 power plants nationwide use coal, natural gas, nuclear fission, wind or sun to generate electricity. The amount of power generated at any given time must match customers’ demand for power exactly, or the system becomes unstable.
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TRANSMISSION: A network of high-voltage power lines delivers large amounts of power over long distances, from power plants to substations in population centers. There are 450,000 miles of transmission lines in the U.S., organized in networks designed to be able to continue to deliver power even if part of the network fails.
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BULK POWER: The power plants and transmission networks make up the bulk power system. The responsibility for setting standards and tracking the performance of this equipment was given to the North American Electric Reliability Corp. after the blackout, as the result of the Energy Policy Act of 2005. Prior to that, NERC promoted reliability through voluntary standards in a system that depended on peer pressure and the interests of various entities in the industry. Many aspects of the system, including pricing and reliability, are regulated by the Federal Energy Regulatory Commission. The plants and wires are operated by investor-owned utilities, transmission companies, and federal nonprofit agencies.
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DISTRIBUTION: This network of smaller lines and equipment delivers low-voltage power from substations to customers through overhead lines and underground cables. Failures in this system from weather or other factors are responsible for most of the outages customers experience. Distribution is handled by hundreds of different investor-owned utilities, municipal utilities and cooperatives. It is regulated at the state level.
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WHAT WENT WRONG: In 2003, trees came into contact with several transmission lines operated by Akron, Ohio-based FirstEnergy Corp., and utilities and regional grid operators failed to stop the outage as the instability cascaded in the regional grid and beyond, eventually affecting 50 million people in eight states and parts of Canada. Investigators said FirstEnergy’s grid management, regional operators’ responses, the tools used to monitor the situation, and communication among the parties involved all contributed to the problem.
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Sources: U.S. Department of Energy, American Society of Civil Engineers, AP research
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