1996 Western North-America summer blackouts
Encyclopedia
The 1996 Western North America blackouts were two widespread power outage
Power outage
A power outage is a short- or long-term loss of the electric power to an area.There are many causes of power failures in an electricity network...

s that occurred across Western Canada
Western Canada
Western Canada, also referred to as the Western provinces and commonly as the West, is a region of Canada that includes the four provinces west of the province of Ontario.- Provinces :...

, the Western United States
Western United States
.The Western United States, commonly referred to as the American West or simply "the West," traditionally refers to the region comprising the westernmost states of the United States. Because the U.S. expanded westward after its founding, the meaning of the West has evolved over time...

, and Northwest Mexico
Northwest Mexico
Northwest Mexico is a region of the United Mexican States, formed by the states of Durango, Sinaloa, Chihuahua, Sonora, Baja California and Baja California Sur...

 on July 2 and August 10, 1996. They were spread 6 weeks apart and were thought to be similarly caused by over-demand during a hot summer.

Though affecting millions, the blackouts were for the most part just an inconvenience, and not emergencies. On both occasions planes continued to take-off and land, and power was restored within a few minutes or hours.

The blackouts raised concerns about the then-recent debates about deregulating electricity utilities.

July 2 blackout

On July 2, 1996, a voltage instability resulted from the loss of steady state equilibrium conditions, caused by reactive power deficiency in the Idaho area. The power failure affected parts of Alberta
Alberta
Alberta is a province of Canada. It had an estimated population of 3.7 million in 2010 making it the most populous of Canada's three prairie provinces...

 and British Columbia
British Columbia
British Columbia is the westernmost of Canada's provinces and is known for its natural beauty, as reflected in its Latin motto, Splendor sine occasu . Its name was chosen by Queen Victoria in 1858...

 in Canada, western Mexico, as well as Idaho, Montana, Utah, New Mexico, California, and Arizona, affecting more than two million people.
Most power was restored in an hour or two.

President Bill Clinton
Bill Clinton
William Jefferson "Bill" Clinton is an American politician who served as the 42nd President of the United States from 1993 to 2001. Inaugurated at age 46, he was the third-youngest president. He took office at the end of the Cold War, and was the first president of the baby boomer generation...

 directed the U.S. Energy Department to investigate the reasons for the widespread power outage and whether it could have been prevented.

August 10 blackout

On August 10, 1996, the western electric grid experienced another massive blackout.

This power outage affected customers in seven western U.S. states, two Canadian provinces, and Baja California
Baja California
Baja California officially Estado Libre y Soberano de Baja California is one of the 31 states which, with the Federal District, comprise the 32 Federal Entities of Mexico. It is both the northernmost and westernmost state of Mexico. Before becoming a state in 1953, the area was known as the North...

, Mexico. Approximately 7.5 million customers lost power for periods ranging from several minutes to six hours. The outage stretched from Canada to New Mexico and knocked out power to 4 million customers amid a triple-digit heat wave.

At 3:42 p.m., a power line sagged into filbert trees near Hillsboro, Oregon
Hillsboro, Oregon
Hillsboro is the fifth-largest city in the U.S. state of Oregon and is the county seat of Washington County. Lying in the Tualatin Valley on the west side of the Portland metropolitan area, the city is home to many high-technology companies, such as Intel, that compose what has become known as the...

, just southwest of Portland
Portland, Oregon
Portland is a city located in the Pacific Northwest, near the confluence of the Willamette and Columbia rivers in the U.S. state of Oregon. As of the 2010 Census, it had a population of 583,776, making it the 29th most populous city in the United States...

. It was the fourth power line in Oregon to fail in less than two hours. Five minutes later, at 3:47 p.m., a line shorted out in Vancouver, Washington
Vancouver, Washington
Vancouver is a city on the north bank of the Columbia River in the U.S. state of Washington. Incorporated in 1857, it is the fourth largest city in the state with a 2010 census population of 161,791 as of April 1, 2010...

, across the Columbia River
Columbia River
The Columbia River is the largest river in the Pacific Northwest region of North America. The river rises in the Rocky Mountains of British Columbia, Canada, flows northwest and then south into the U.S. state of Washington, then turns west to form most of the border between Washington and the state...

 from the Portland/Hillsboro area. At 3:48 p.m., the 13 turbines at McNary Dam
McNary Dam
McNary Dam is a 1.4-mile long concrete gravity run-of-the-river dam which spans the Columbia River. It joins Umatilla County, Oregon with Benton County, Washington, 292 miles upriver from the mouth of the Columbia at Astoria, Oregon. It is operated by the U.S. Army Corps of Engineers' McNary...

, on the Columbia about 190 miles upstream from Portland, tripped off line.
Inadequate tree-trimming practices, operating studies, and instructions to dispatchers played a significant role in the severity of this disturbance.
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