Although the Sept. 8 outage, apparently caused by human
error, was just a tenth the size of the 2003 blackout that left about 50
million people without power in the eastern United States and Canada, it will
surely rank as one of the biggest blackouts in recent history — certainly one
of the biggest caused by human error.
Sempra Energy’s San Diego Gas & Electric power company
said it restored power to its 1.4 million customers at 3:25 a.m. Western time
on Friday.
That was almost 12 hours after a major electric transmission
system outage in western Arizona and the loss of a key connection with the
2,150-megawatt San Onofre nuclear power plant in California resulted in the
most widespread power outage in the company’s history, SDG&E said.
Across the border in Baja California, where 3.5 million
people were affected by blackouts, power had been restored to 1.1 million
customers by 6 a.m. local time, Mexico’s Federal Electricity Commission said in
a statement.
“Service is practically back to normal, with only some
specialized industrial clients awaiting reconnection,” it said.
San Onofre, which is operated by Edison International’s
Southern California Edison, shut on Thursday and remained out of service early
Friday, according to the U.S. Nuclear Regulatory Commission.
“Restoring power in the aftermath of the loss of the entire
local grid serving San Diego and southern Orange counties was a monumental
task,” David Geier, SDG&E vice president of electric operations, said in a
release.
“The restoration process, however, has left our local power
grid very fragile and we are asking our customers to conserve electricity
throughout the day Friday,” Geier said.
SDG&E and the California ISO, which operates the power
grid for much of the state, said they would focus on maintaining and ensuring
the integrity of the local power system for the next few days before
determining the sequence of events that led to the outage and establishing
practices and procedures to ensure that outages such as the Sept. 8 event are
not repeated.
“There appears to be two failures here -- one is human
failure and the other is a system failure. Both of those will be addressed,”
said Damon Gross, a spokesman for Pinnacle West Capital’s Arizona utility
Arizona Public Service.
