2011 Southwest blackout
Encyclopedia
The 2011 Southwest blackout, sometimes referred to as the Great Blackout of 2011, was a widespread power outage
that affected large areas of Southern California
as well as western Arizona
and northern Baja California
and Sonora
. It occurred on Thursday, September 8, 2011, beginning at about 3:38 PM PDT. It was the largest power failure in California
history.
, a subsidiary of Sempra Energy
, although southern Orange County
and parts of Riverside County
were also affected. The blackout left nearly seven million people without power, including 1.4 million customers in San Diego County and 1.1 million customers in Mexico. The outage was the result of 23 distinct events that occurred on 5 separate power grids in a span of 11 minutes. Federal, regional and local officials are investigating what happened and why the outage cascaded the way it did. The Arizona Public Service
(APS) North Gila Substation reported power loss at 2:27 pm. Within seconds a portion of a Mexico power plant shut down, but there is no indication that Arizona impacted Mexico. Units 2 and 3 at San Onofre Nuclear Generating Station
automatically tripped offline due to a "grid disturbance" which initiated the plant's Emergency Feed Actuation System (EFAS).
The hardest hit region of the blackout, the San Diego-Tijuana metropolitan area, was essentially brought to a standstill. Surface streets became gridlocked due to the loss of traffic signals, and the San Diego skyline went dark. The San Diego Trolley
system was shut down as there was no power to operate signal lights and related functions, and trains were stopped in Los Angeles
for the same reason. Citizens in Tijuana
and in inland areas like the Coachella Valley
stayed outdoors late into the night to escape the heat. Freeways in the Southern California megalopolis experienced extreme clogging, especially on the I-15 and I-5 corridors between southwestern Greater Los Angeles and the San Diego area's North County. One hospital was left without power for two hours when its backup generator failed.
were closed on September 9. So were the major universities, the community colleges, and the Federal court system.
The outage caused significant losses to restaurants and grocery stores, which were forced to discard quantities of spoiled food; perishable food losses at grocery stores, eating establishments and households were estimated at $12 million to $18 million. The outage also caused some sewage pumping stations to fail, resulting in contaminated beaches and potentially unsafe water supplies in several areas. As a precaution, in some neighborhoods, residents were told to boil their water or use bottled water for several days after the outage.
warned of a potential terrorist attack leading up to the anniversary, so that a first reaction to the blackout was to wonder if it might be the result of an attack. However, the Federal Bureau of Investigation
and San Diego Gas & Electric
ruled out terrorism early in their investigation, and no subsequent evidence was found to suggest that the outage was anything other than accidental.
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...
that affected large areas of Southern California
Southern California
Southern California is a megaregion, or megapolitan area, in the southern area of the U.S. state of California. Large urban areas include Greater Los Angeles and Greater San Diego. The urban area stretches along the coast from Ventura through the Southland and Inland Empire to San Diego...
as well as western Arizona
Arizona
Arizona ; is a state located in the southwestern region of the United States. It is also part of the western United States and the mountain west. The capital and largest city is Phoenix...
and northern 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...
and Sonora
Sonora
Sonora officially Estado Libre y Soberano de Sonora is one of the 31 states which, with the Federal District, comprise the 32 Federal Entities of Mexico. It is divided into 72 municipalities; the capital city is Hermosillo....
. It occurred on Thursday, September 8, 2011, beginning at about 3:38 PM PDT. It was the largest power failure in California
California
California is a state located on the West Coast of the United States. It is by far the most populous U.S. state, and the third-largest by land area...
history.
Effect
Most of the affected areas are served by San Diego Gas & ElectricSan Diego Gas & Electric
San Diego Gas & Electric is the utility that provides natural gas and electricity to San Diego County and southern Orange County in southwestern California, United States...
, a subsidiary of Sempra Energy
Sempra Energy
Sempra Energy is a Fortune 500 energy services holding company based in San Diego, California. It divides its interests into two broad categories: Sempra Utilities, including Pacific Enterprises/Southern California Gas Company and San Diego Gas & Electric; and Sempra Global, a holding company for...
, although southern Orange County
Orange County, California
Orange County is a county in the U.S. state of California. Its county seat is Santa Ana. As of the 2010 census, its population was 3,010,232, up from 2,846,293 at the 2000 census, making it the third most populous county in California, behind Los Angeles County and San Diego County...
and parts of Riverside County
Riverside County, California
Riverside County is a county in the U.S. state of California. One of 58 California counties, it covers in the southern part of the state, and stretches from Orange County to the Colorado River, which forms the state border with Arizona. The county derives its name from the city of Riverside,...
were also affected. The blackout left nearly seven million people without power, including 1.4 million customers in San Diego County and 1.1 million customers in Mexico. The outage was the result of 23 distinct events that occurred on 5 separate power grids in a span of 11 minutes. Federal, regional and local officials are investigating what happened and why the outage cascaded the way it did. The Arizona Public Service
Arizona Public Service
Arizona Public Service Company is the largest electric utility in Arizona and the principal subsidiary of publicly-traded S&P 500 member Pinnacle West Capital Corporation , which in turn had been formerly named AZP Group, when Arizona Public Service reorganized as that holding company in 1985.With...
(APS) North Gila Substation reported power loss at 2:27 pm. Within seconds a portion of a Mexico power plant shut down, but there is no indication that Arizona impacted Mexico. Units 2 and 3 at San Onofre Nuclear Generating Station
San Onofre Nuclear Generating Station
The San Onofre Nuclear Generating Station is a nuclear power plant located on the Pacific coast of California. The site is in the northwestern corner of San Diego County, south of San Clemente, and surrounded by the San Onofre State Park and next to the I-5 Highway.Unit 1 is no longer in service...
automatically tripped offline due to a "grid disturbance" which initiated the plant's Emergency Feed Actuation System (EFAS).
The hardest hit region of the blackout, the San Diego-Tijuana metropolitan area, was essentially brought to a standstill. Surface streets became gridlocked due to the loss of traffic signals, and the San Diego skyline went dark. The San Diego Trolley
San Diego Trolley
The San Diego Trolley is a light rail system operating in the metropolitan area of San Diego. The operator, San Diego Trolley, Inc. , is a subsidiary of the San Diego Metropolitan Transit System ...
system was shut down as there was no power to operate signal lights and related functions, and trains were stopped in Los Angeles
Los Ángeles
Los Ángeles is the capital of the province of Biobío, in the commune of the same name, in Region VIII , in the center-south of Chile. It is located between the Laja and Biobío rivers. The population is 123,445 inhabitants...
for the same reason. Citizens in Tijuana
Tijuana
Tijuana is the largest city on the Baja California Peninsula and center of the Tijuana metropolitan area, part of the international San Diego–Tijuana metropolitan area. An industrial and financial center of Mexico, Tijuana exerts a strong influence on economics, education, culture, art, and politics...
and in inland areas like the Coachella Valley
Coachella Valley
Coachella Valley is a large valley landform in Southern California. The valley extends for approximately 45 miles in Riverside County southeast from the San Bernardino Mountains to the saltwater Salton Sea, the largest lake in California...
stayed outdoors late into the night to escape the heat. Freeways in the Southern California megalopolis experienced extreme clogging, especially on the I-15 and I-5 corridors between southwestern Greater Los Angeles and the San Diego area's North County. One hospital was left without power for two hours when its backup generator failed.
Aftermath
Eleven hours after the outage began, power was restored to 694,000 of the affected customers, and by 4:30 AM on September 9 power was restored to all customers, although the system was described as "still fragile". All public schools in San Diego County and some in Orange CountyOrange County, California
Orange County is a county in the U.S. state of California. Its county seat is Santa Ana. As of the 2010 census, its population was 3,010,232, up from 2,846,293 at the 2000 census, making it the third most populous county in California, behind Los Angeles County and San Diego County...
were closed on September 9. So were the major universities, the community colleges, and the Federal court system.
The outage caused significant losses to restaurants and grocery stores, which were forced to discard quantities of spoiled food; perishable food losses at grocery stores, eating establishments and households were estimated at $12 million to $18 million. The outage also caused some sewage pumping stations to fail, resulting in contaminated beaches and potentially unsafe water supplies in several areas. As a precaution, in some neighborhoods, residents were told to boil their water or use bottled water for several days after the outage.
Question of association with terrorism
The outage occurred days before the tenth anniversary of the September 11 attacks, and hours before the United States Department of Homeland SecurityUnited States Department of Homeland Security
The United States Department of Homeland Security is a cabinet department of the United States federal government, created in response to the September 11 attacks, and with the primary responsibilities of protecting the territory of the United States and protectorates from and responding to...
warned of a potential terrorist attack leading up to the anniversary, so that a first reaction to the blackout was to wonder if it might be the result of an attack. However, the Federal Bureau of Investigation
Federal Bureau of Investigation
The Federal Bureau of Investigation is an agency of the United States Department of Justice that serves as both a federal criminal investigative body and an internal intelligence agency . The FBI has investigative jurisdiction over violations of more than 200 categories of federal crime...
and San Diego Gas & Electric
San Diego Gas & Electric
San Diego Gas & Electric is the utility that provides natural gas and electricity to San Diego County and southern Orange County in southwestern California, United States...
ruled out terrorism early in their investigation, and no subsequent evidence was found to suggest that the outage was anything other than accidental.
See also
- 1996 Western North America blackouts
- California electricity crisisCalifornia electricity crisisThe California electricity crisis, also known as the Western U.S. Energy Crisis of 2000 and 2001 was a situation in which California had a shortage of electricity caused by market manipulations and illegal shutdowns of pipelines by Texas energy consortiums...
- Northeast Blackout of 2003Northeast Blackout of 2003The Northeast blackout of 2003 was a widespread power outage that occurred throughout parts of the Northeastern and Midwestern United States and Ontario, Canada on Thursday, August 14, 2003, just before 4:10 p.m....
- Path 46Path 46Path 46, also called West of Colorado River, Arizona-California West-of-the-River Path , is a set of many alternating current high-voltage transmission lines that are located in southeast California and Nevada up to the Colorado River...
, also called West of Colorado River, Arizona-California West-of-the-River Path (WOR)