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Studies show command failures helped fuel blackout
Editor’s note: This is the first of a three-part series on the anniversary of last year’s blackout across much of the Northeast. Part two will appear on Sunday’s Business page.
Failures in both command and control, as well as ignoring simple vegetative maintenance along power line rights of way, led to the massive power blackout of Aug. 14, 2003, according to two in-depth, independent studies of the outage.
The loss of electricity surged across portions of Ohio, Michigan, New York, Pennsylvania, New Jersey, Connecticut, Massachusetts and Vermont, as well as the Canadian provinces of Ontario and Quebec.
Ultimately, 50 million customers saw their lights wink out and their air conditioners stop cold. While most of these customers were without electricity for only a few hours, some areas of the United States sweltered without power for up to two days.
And portions of Ontario suffered rotating blackouts for as long as two weeks.
In what power regulating and generating officials called a "cascade effect," the stampeding outage began in the Cleveland area with a set of circumstances that included human error.
FirstEnergy’s role
At the vortex of the blackout was Akron-based FirstEnergy Corp.
FirstEnergy is the nation’s fifth-largest electrical utility and serves 4.4 million customers in a 36,100-square-mile area covering portions of Ohio, Pennsylvania and New Jersey.
The firm operates 11,502 miles of transmission lines, and has 84 ties with 13 other electrical systems.
A joint U.S.-Canada task force review of last year’s incident, along with an investigation by the ad hoc industry-related group designed to monitor energy transmission reliability, each issued a scathing document on the blackout.
Neither report minced words on the failures of both power suppliers and monitors in doing their jobs properly.
Several conditions led to the blackout, including the loss of FirstEnergy’s coal-fired power plant’s 597-megawatt Unit 5 in Eastlake, Ohio, about 20 miles east of Cleveland.
This unit shut down at 1:31 p.m., Aug. 14, 2003, because an operator there sought to increase output in response to a request made by the company’s system operator.
This loss compelled FirstEnergy to import additional power, making "voltage management in northern Ohio more challenging," and gave FirstEnergy operators less flexibility in operating their system, says the North American Electric Reliability Council’s final 124-page report on the incident.
NERC is the nonprofit corporation embracing all elements of the power generation industry including producers, suppliers and government regulators.
Officials with NERC investigated the blackout, declaring that it " ‘looked under every rock’ and methodically proved or disproved each theory" as to why the event occurred.
With two FirstEnergy generators already shut down -- the firms’ Davis-Besse Nuclear Power Plant near Toledo as well as Eastlake’s Unit 4 -- the loss of Eastlake’s Unit 5 "further depleted critical voltage support for the Cleveland-Akron area," the report stated.
"Detailed simulation modeling reveals that the loss of Eastlake 5 was a significant factor in the outages later that afternoon," the report said.
Concerns expressed by Eastlake’s operators were noted in taped conversations between officials at the plant and those elsewhere.
During the Eastlake episode, its operator reported to superiors at 1:16 p.m. -- and documented in the NERC report -- that "we got a way bigger load than we thought we would have. So we’re starting to sag all over the system."
Such frantic pleas were common during the hours and minutes leading up to the power outage.
In another exchange between an operator at the Bayshore coal-fired power plant near Detroit and FirstEnergy’s nuclear power plant in North Perry Village, located about 18 miles to the east ofthe firm’s Eastlake coal-fired plant, it was clear that something had gone wrong.
"Give me what you can. I’m hurting," the Bayshore operator said to his North Perry counterpart.
However, the report also notes the loss of Eastlake’s Unit 5 likely did not inspire the blackout.
Even so, had Eastlake’s Unit 5 remained up and running, subsequent loadings on several electrical transmission lines "would have been slightly lower and outages due to tree contacts might have been delayed; there is even a remote possibility that the line trips may not have occurred," the NERC report concluded.
Tripped by trees
It is those line contacts with trees which is at the heart of the matter, the report states.
Within a 37-minute period starting at 3:05 p.m., three FirstEnergy transmission lines supplying energy to the Cleveland-Akron area tripped -- or interrupted current flow --because of their contact with overgrown trees along the lines’ rights of way.
These overloaded wires had begun to droop, touching the vegetation, with FirstEnergy alarm processor failure also occurring.
Two additional lines later went down for the same reason, shifting electricity onto a network of transmission lines "not designed to carry such large amounts of power," and which quickly became overloaded, the NERC report says.
As a result, the increased voltages began to degrade in the Akron area, tripping 16 power lines during a 30-minute period in what can be best described as a rapid meltdown of the 138-kilovolt system in northern Ohio.
Loss of all these electrical pathways quickly overloaded the region’s remaining major transmission line: FirstEnergy’s Sammis-Star 345-kilovolt line, located near Akron.
When that line tripped at 4:05 p.m. -- and just after the Eastlake incident -- it was the beginning of "an uncontrollable cascade of the power" grid, the NERC report concludes.
It was at this moment that "the last point at which a cascade of line trips could have been averted" was reached, the report stated.
All the while FirstEnergy officials failed to evaluate the system to determine whether it could withstand loss of other major equipment elsewhere.
Neither did the firm’s operators evaluate the loss of Eastlake Unit 5 in order to determine whether the shutdown of another line or generating unit would put the utility’s entire system in jeopardy.
At 4:10 p.m., the last remaining major transmission path and transformer between the eastern interconnection and the blackout area was compromised. This was the 69-mile long Branchburg-Ramapo line and transformer between New York and New Jersey.
By 4:13 p.m., more than 608 generating units at 265 power stations had ceased operation.
"The loss of the heavily overloaded Sammis-Star line instantly created major and unsustainable burden on other lines, first causing a ‘domino-like’ sequence of line outages westward and northward across Ohio and into Michigan, and then eastward, splitting New York from Pennsylvania and New Jersey," the report’s findings state.
Improvement needed
The report further states that FirstEnergy likewise could have benefited from better assistance from the Carmel, Ind.-based Midwest Independent Transmission System Operator.
MISO is the transmission organization designated to monitor the regional electrical reliability in an area encompassing more than 11,000 miles of high voltage lines in 15 states and one Canadian province.
MISO became FirstEnergy’s reliability coordinator on Feb. 1, 2003, but the utility didn’t become a full member until Oct. 1, 2003 -- fully six weeks after the blackout.
The NERC report also stated that MISO lacked "visual tools" and encountered "computer problems."
A combination of human error and ineffective updating of line status information to the MISO state estimator contributed to the problem, the report further said.
"This blackout could have been prevented and that immediate actions must be taken in both the United States and Canada to ensure that our electric system is more reliable," according to the preamble to the joint U.S.-Canada report.
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