Since I posted that bit about TV maps excluding PA, I've seen others which include it. Obviously, we are still learning the scope, seriousness, and causes of this one. Here's one answer. From MSNBC
This part makes the most early sense:
Wollenberg said he has heard talk among others in the electrical engineering community that the competitive atmosphere of deregulation has led some utilities and energy companies to skimp on maintenance and purchase of new equipment.
Trouble on grid can spread quickly
msnbc.com
Experts on the U.S. power grid said the extent of Thursday's blackouts in the Northeast and Canada suggests a combination of equipment failure and hot weather overwhelmed the heavily taxed system.
"IF THE SYSTEM is teetering on the edge and then they lost a transmission (sector) or a power plant, that could affect utilities quite a distance away," Bruce Wollenberg, a professor of electrical engineering at the University of Minnesota and co-author of "Power Generation, Operation, and Control," told MSNBC.com as early reports of the power failures rolled in.
He said that historically, many of the worst U.S. blackouts have occurred on "afternoons on a July or August day when it's very, very hot."
High temperatures in the affected area Thursday ranged from the low 80s in upstate New York to the upper 80s in New York City, Detroit and Toronto.
Industry leaders were continuing to search Friday for the cause of what was being called the biggest power failure in history. The latest evidence suggested the problem may have been triggered not in upstate New York or Canada, as some had speculated, but somewhere along Lake Erie in Ohio, according to the industry-sponsored group that monitors the transmission system.
"That's where the information is starting to point," Ellen Vancko, a spokeswoman for the North American Electric Reliability Council, said in an interview. "It looks like that's where the collapse started."
But New York City Mayor Michael Bloomberg said data he had seen indicated the problem began in Canada and required New York utilities to suddenly increase northward transmissions.
The Canadian prime minister's office had said late Thursday that the blackout was caused when lightning struck a power plant in Niagara, N.Y., though the National Weather Service reported clear skies in the area. Earlier reports from authorities in New York indicated that the blackouts were triggered when the power grid of the Syracuse-based Niagara Mohawk utility became overloaded.
PROBLEMS CAN SPREAD QUICKLY
Though the sequence of events after the initial failure was unclear, Wollenberg said that what began as a localized problem could have spread quickly around the eastern regional power grid if other utilities in the system were running near capacity to meet increased demand.
"When something like that happens in the summer on a very hot afternoon, the rest of the system gets loaded up higher," he said. "It's like the highway system. As soon as they block something off, then all the streets and roads around it get overloaded."
University of Illinois engineering Professor Thomas Overbye, who has done extensive studies on the grid's reliability, agreed that one problem could have caused the large pockets of darkness that extended as far west as Michigan.
"In the electric grid there's a good amount of redundancy, but if you lose enough lines, problems can spread," he said. "One of the potential risks of having an interconnected system is that power problems can spread very quickly."In situations where utilities can foresee that demand will outstrip supply, such as happened last summer during California's energy crisis, utilities can institute "rolling blackouts," which means cutting off electricity to certain areas for short periods of time to lessen overall energy demand.
But a sudden failure on a day when the system already is running near its maximum capacity leaves no time to institute such mitigation measures.
TRANSMISSION CAPACITY LACKING
Another factor that could have come into play is that the way electricity is moved among utilities has changed since the energy industry was deregulated in the 1990s, said Overbye.
"Interstate shipment of electric power takes place all the time, but there is just not enough transmission capacity to meet all of the needs," he said. That's because "the high-voltage electric transmission system was originally designed to meet the needs of local utilities," he added, not for shipping electric power over hundreds of miles.
The difficulty in tracking down the cause of the failure illustrates the increasing complexity of the North American electricity network, which in recent decades has seen a boom in cross-border power trading, and the interdependence of the many parts and partners multiplied by energy deregulation.
About 3,170 electric utilities are connected into the U.S. power grid, grouped into three smaller groups. Thursday's outages occurred in the Eastern Interconnected System, which extends throughout the Northeast and into the Midwest and Canada.
When one utility has a shortage, it can buy electricity from regional transmission organizations (RTOs) or an independent power generator, which essentially produces energy on a free-lance basis.
Like a river's tributaries, their contributions spill into immense regional power grids, where they become anonymous and untraceable. Managers at dozens of control sites monitor intricate crosscurrents of supply and demand, watching over their delicate balance.
Because of that interconnectivity, a single failure can reverberate through the system and set off a catastrophic chain reaction.
The blackout already has spawned talk of overhauling the national electrical grid which many characterized as antiquated and raised new questions about whether deregulation of the power industry might have played a part in Thursday's disruptions.
"We're the world's greatest superpower, but we have a Third World electricity grid," said former Energy Secretary Bill Richardson, now governor of New Mexico.
Wollenberg said he has heard talk among others in the electrical engineering community that the competitive atmosphere of deregulation has led some utilities and energy companies to skimp on maintenance and purchase of new equipment.
"You do that at your own peril," he said, adding that he had no direct knowledge that companies were cutting back in those areas.
MSNBC.com's Tom Curry and Julia Chai |
