viernes, 24 de agosto de 2012

World’s Worst Power Outages

Northeastern U.S. and Canada, 1965

Photograph by Bob Gomel, Time Life Pictures/Getty Images
A full moon created an eerie skyline silhouette after New York City went dark during the blackout of November 1965. In a world that's increasingly dependent on constant power, massive electrical outages are a common concern and may strike systems across the globe.
Major power disturbances can be triggered by storms, heat waves, solar flares, and many other sources, but all have roots in the mechanical and human vulnerabilities of the power grids themselves. "Power delivery systems have a lot of parts, wires, transformers and other components all nicely tied together—which means there are a lot of things that can go wrong," explained Clark Gellings of the nonprofit Electric Power Research Institute. "Pieces break down and people make errors. A system is designed to tolerate a certain amount of disruption but past a certain point, it's simply gone too far and it falls apart."
The "great Northeast blackout," which began when a power surge near Ontario set off a chain of failures across New York State and beyond, covered 80,000 square miles. "Within four minutes the line of darkness had plunged across Massachusetts all the way to Boston," reported The New York Times on the day of the outage. "It was like a pattern of falling dominoes-darkness sped southward through Connecticut, northward into Vermont, New Hampshire, Maine and Canada."
Brian Handwerk

India, 2012

Photograph by Channi Anand, AP
A girl prepares food by candlelight in Jammu, India on August 1, 2012. India's massive power failures on July 30 and 31 were unprecedented in size and left 670 million people without electricity across the nation's north and east.
Before power was restored on August 1, about half of all residents of India—nearly 10 percent of the entire world's population—were left in the dark by a cascade of collapsing regional systems. The outage's exact cause may be debatable, but the ultimate source of trouble was predictable: India's power structure is often unable to meet peak power demands. Prime Minister Manmohan Singh has called for a $400 billion investment to help increase the capacity and reliability of India's power grid, but the country's efforts to build "ultra-mega" coal plants have hit economic snags, while its effort to build the world's largest nuclear power plant faces protests and delays.

Operating Without Power, 1965

Photograph by Ted Russell, Time Life Pictures/Getty Images
Doctors use temporary lighting to perform brain surgery at St. Vincent's Hospital in New York City during the great blackout of 1965. More than 30 million people in parts of Canada and several Northeastern U.S. states were left without power for up to 13 hours on November 9, 1965, after the lights went dark during the evening rush hour. A faulty or improperly set safety relay at an Ontario power station was blamed for sparking a southbound power surge that overwhelmed systems from Vermont to New Jersey. Human operators were also faulted for responses that failed to contain the crisis.

Europe, 2006

Photograph by Joerg Sarbach, AP
Onlookers wait for the newly built cruise ship Norwegian Pearl to leave the Papenburg, Germany shipyard in November 2006. Soon after, on its trip down the River Ems, the ship indirectly caused a two-hour power outage for some 10 million people on the evening of November 4.
The German power company E. turned off a 380,000-volt line over the river so that the ship could pass safely beneath on its way to the North Sea. But the dead line quickly increased pressures elsewhere in the German power grid and then sparked a chain reaction across parts of Germany, France, Belgium, Italy, Spain, Austria, the Netherlands, and Croatia. Critics said the incident showcased the need for more universal electricity distribution policies across Europe.

New York, 1977

Photograph by Tom Cunningham, NY Daily News/Getty Images
A lack of power poses plenty of inherent problems, but massive blackouts can also lead to bad behavior. A lightning-sparked outage in 1977, which left 9 million New Yorkers without power, lasted only about 24 hours on July 13 and July 14. But during that time, arsonists torched buildings like these on Marmion Avenue in the Bronx, setting a reported 1,000 fires. Looters and rioters also ran rampant and trashed some 1,600 stores during what Mayor Abraham Beame called "a night of terror." When similar outages struck the city in 2003, however, such problems were few and far between.

Northeastern U.S. and Canada, 2003

Photograph by Andrew Lichtenstein, Corbis
On August 15, 2003, a mass of New York commuters crossed the Brooklyn Bridge on foot during a blackout that robbed 50 million people of power for as long as two days in southeastern Canada and the Northeastern United States. It also crippled all trains, stranding many travelers. The U.S.-Canada Power System Outage Task Force determined that equipment failures and human error had combined to cause the blackout, which started when power lines shut down after contact with trees.
An improving ability to monitor the exact condition of the power system at any given instant with voltage and current sensors, and to make rapid changes like taking lines out of service, is critical to avoiding the cascading effects that lead to widespread outages like the 2003 event.
"If something goes wrong and an ice storm brings down a line or someone blows up a transmission tower that will propagate a disturbance and we need to know exactly how far it propagates and exactly what it looks like—like the ripples of a pebble dropped into a pond, so that we can take a definitive corrective action," said EPRI's Clark Gellings. "When that capability doesn't exist, like it didn't in 2003 in the United States, the system is set up for some kind of failure."

Related Posts Plugin for WordPress, Blogger...