Some things do work
dusty2 said:
THIS WORLD SUCKS BIG TIME! NOTHING SEEMS TO WORK! WONDER WHY?
It could have been worse. The techs in Valley Forge should be commended. I had trouble at work but at home power had to have been out for less than a minute.
Why we were spared
By Akweli Parker, Tom Avril and Kevin Dale
Inquirer Staff Writers
Technicians in Valley Forge saw the sudden power surge. Circuit breakers tripped. And within four minutes, the electricity grid that serves Pennsylvania and New Jersey had clamped off the spike that blacked out much of the Northeast yesterday, shielding Philadelphia and points south from the disruption.
As a result, the Mid-Atlantic grid, operated by Valley Forge-based PJM Interconnection L.L.C., experienced only a few spillover blackouts in sections of northern Pennsylvania and northern New Jersey.
Details on what triggered the blackout were still sketchy last night. Canadian officials said it might have originated at a Pennsylvania nuclear plant, but a state official stoutly denied it.
"It's not true," said Maria Smith, spokeswoman for the Pennsylvania Emergency Management Agency. "All five nuclear power plants in the state have been running at 100 percent power all day, all night. No problems. Not even a trash-can fire.
"What we're hearing is that it resulted from a disruption in the power grids in the states to the north and east of us, and cascaded into the Commonwealth."
The outage affected a huge swath of the Northeast, stretching from New England to Detroit and into Canada.
PJM's quick action, coupled with ample power-generating capacity throughout the region, kept the incident from crippling Philadelphia, Harrisburg and Washington, said PJM president Phillip G. Harris.
Working inside the company's nondescript building in an office park, technicians fed reserve power into the grid to smooth out irregularities caused by the surge - keeping the region's lights on. PJM, which operates around the clock, brought in an extra shift of technicians to help out.
It was the kind of moment PJM's technicians practice for, Harris said: "Coordination is rehearsed and drilled several times a year."
By last evening, PJM was sending a modest amount of its reserve power to New York's system, with more available once New York and others cities were capable of handling it.
The Nuclear Regulatory Commission reported that nine nuclear reactors at seven sites, including the Oyster Creek plant in Lacey Township, N.J., shut down automatically, as they are designed to do, when they lost their off-site power supplies. It could take 24 hours or more to restart them.
PJM runs what it says is the largest wholesale electricity market in the world. Its experts estimate how much electricity is needed to serve an area that is home to more than 25 million people, then accept bids from electricity generators and wholesalers to supply the needed energy.
It also is responsible for making sure electricity is available reliably throughout its Mid-Atlantic grid, a system that supplies power to all or parts of Pennsylvania, New Jersey, Maryland, Delaware, Virginia, Ohio, West Virginia and Washington, D.C. Among the companies that participate in the grid are Peco Energy Co. and Public Service Electric & Gas Co.
David Sanko, director of the Pennsylvania Emergency Management Agency, said at least parts of seven counties in the northwestern section of the state lost power.
Sanko said power was beginning to be restored by 6 p.m.
PJM technicians saw electricity usage in the area under their control drop suddenly by about 5,200 megawatts shortly at 4 p.m. One megawatt is enough electricity to power 750 to 1,000 homes.
"The protective equipment did work... . It operated exactly like it's supposed to," Harris said.
That said, no electric grid is bulletproof, said Chika Nwankpa, professor of electrical and computer engineering at Drexel University.
"During high-temperature conditions, all [regional power operators] are vulnerable," said Nwankpa, who has worked with PJM and several of the region's electric utilities on assorted projects.
Often, blackouts occur when the demand of electricity customers is greater than the amount of electricity being cranked out by power plants.
Likely a number of giant circuit breakers - typically located in a free-standing building at least 40 feet tall - automatically tripped so that dangerously high current did not flow into the Pennsylvania-New Jersey-Maryland region. Otherwise, according to Vijay Vittal, professor of electrical engineering at Iowa State University, there would have been problems over an even wider area.
"If such a large area was affected, it must be a very severe disturbance," said Vittal, member of a national industry-university research group that studies the reliability of the power system. "It could have spread to your area... . If nothing had been done, it could have probably extended out to Iowa and Nebraska."
Protective circuit breakers apparently did not activate quickly enough to protect the region containing Cleveland and Detroit, Vittal said.
"All this happens in fractions of seconds," Vittal said. "This is a very classical cascading outage."
http://www.philly.com/mld/inquirer/6535863.htm