Millions of Paths to Blackout

Equipment failure, procedural and design flaws and human error may all have contributed to last week’s sweeping power outage, experts said Monday, as electrical engineers began poring over millions of bits of data to find the cause.

The data represent voltage fluctuations, circuit-breaker trips and reversals in electricity flow recorded by utility companies during the three minutes it took for the outage to spread across 9,300 square miles of North America.

The inherent difficulty of the investigation has been compounded, experts said, by the fact that although the continent’s electrical grids are linked, the systems are essentially local -- the data from the blackout stored at sites from Akron, Ohio, to Long Island, N.Y.

“You have a variety of companies with a variety of different types of facilities and you have to collect the data from each of them and then compare,” said Kristen Baird of Ohio-based FirstEnergy Corp., some of whose lines were among the first to fail. “You have to see what circuit went down when, what other systems were doing right before and after it went down, and compare. It’s extremely, extremely complex.”

The inquiry is being headed by the Department of Energy, with the help of the utilities and several other state and federal regulatory bodies, including the North American Electric Reliability Council, or NERC, which estimates it has at least 10,000 pages of data to comb through before issuing a preliminary finding in a week or so.

A final report is expected to take several weeks.

With electrons hurtling through the system at 186,000 miles per second, the speed of light, one of the first tasks facing investigators is to build a timeline of the collapse broken down into milliseconds.

This, experts said, would help determine the sequence of failures, which in turn should suggest why various parts of the system did not isolate themselves after detecting trouble nearby, as they are supposed to do.

“Part of the problem is that the stuff we thought was in place to prevent this kind of thing didn’t work,” said Mark Bernstein, an energy policy analyst with the Rand Corp. “When you get into a situation where one of the parts of the system is having a problem, the other parts are supposed to be able to cut themselves off and maintain operations.... It may be a combination of a lot of things that failed.”

As electrical gumshoes try to figure out what went wrong, a few are also looking at what went right, investigating parts of the system that did indeed cut away as the grid began collapsing.

Most of Central and Southern Ohio, for example, never lost power, even though Cleveland and other cities in the north went black. Officials from the Ohio Public Utilities Commission headed out Monday to see how those operators managed to keep the lights on.

The outage has prompted many lawmakers, investors and the public to call for stricter federal oversight.

The Bush administration has attempted to convert concern over the reliability of the national electricity supply into support for its energy plan -- a proposal criticized by opponents as promoting increased drilling and mining of fossil fuels instead of encouraging energy conservation and alternative fuels.

“What we’re pursuing is a comprehensive energy plan that will ... solve the problems that are before us, that will address the challenges that we face,” White House spokesman Scott McClellan said Monday. “We’re going to continue to work with Congress and get the most comprehensive energy plan we can passed.”The last major blackout offers some lessons in what the coming weeks may bring.

In the summer of 1996, the West suffered a blackout double-header, the first in July, the second a month later, both caused when trees tangled with power lines and knocked out power from British Columbia to Baja California.

The July incident, which started in Idaho, blacked out 2 million customers. The August event, which began in Oregon, turned out the lights for 7.5 million customers.

The Western Systems Coordinating Council, one of 10 regional groups nationwide that self-police electric reliability, determined that poor tree trimming and a lack of communications among utilities allowed the outages to cascade through the system.

It took the council, now known as the Western Electricity Coordinating Council, three months to fully investigate the outages and issue a final report and more than 100 recommendations for improving the system.

Three years went by before the most important change came to pass, one similar to that sought by NERC: The council now has the power to penalize members that violate operating standards, such as failing to maintain the proper frequency on power lines.

Calls for federal oversight, however, went nowhere.

By late Monday, the power was back on for almost all the tens of millions of customers affected, and worries that the start of the workweek would overload the still-shaky grid seemed for naught. Detroit residents were told they no longer needed to boil their drinking water, and New Yorkers were back to commuting by car and train rather than foot and bicycle.

Despite the cautioning of several regulatory bodies that it was simply too early to cast blame, investors pummeled FirstEnergy, which was already suffering before some of its lines were determined to be among the first to fail. Stock in the nation’s fourth-largest utility holding company closed at $27.75, down $2.86 a share, or 9.34%, on the New York Stock Exchange.

In early 2002, the company was forced to shut down its Davis-Besse nuclear plant east of Toledo after an inspection revealed that a leak of boric acid, unchecked for years, had burned a hole nearly through the lid of a reactor. The plant is scheduled to reopen this fall.

Earlier this month, an internal audit forced the company to restate its earnings, which drove its stock price down. Two days after that, a federal judge found that the company had violated the Clean Air Act when it rebuilt another plant without the proper smog controls.

As the investigation unfolds, there will likely be blame enough to go around, experts said.

“A lot of the initial reports have been anecdotal, calls from grid operators and so forth,” said Dan Riedinger of the Edison Electric Institute, an industry trade group. “But most of [the blackout] was recorded in real-time on computers. They’ll find out what happened.”

Times staff writers Nancy Rivera-Brooks in Los Angeles and Maura Reynolds in Waco, Texas, contributed to this report.