Many theories, few answers
August 16, 2003

BY H. JOSEF HEBERT

WASHINGTON--Investigators Friday focused on an electrical transmission loop that encircles Lake Erie as they tried to understand the massive power blackout.

Although no cause has been determined, officials were taking particular interest in a series of power line interruptions that occurred in the Cleveland area during the hour before the blackout hit Thursday.

Two minutes after the last of these Cleveland area line problems, there were ''power swings noted in Canada and the eastern U.S.,'' said a document made public late Friday by the North America Electric Reliability Council.

But the NERC document cautioned ''it's not clear if these events caused the [wider blackout] or were a consequence of other events.''

Public Utilities of Ohio Chairman Alan Schriber said that the information from NERC was inconclusive but that ''it's in the realm of possibility'' that power was being drawn from FirstEnergy from outside its system because of increased power demand.

''Everybody's trying to point their finger at Ohio. By golly, maybe it's not Ohio,'' Schriber said. ''I don't know who that would be, and they [NERC] don't either.''

Meanwhile, the White House announced a U.S.-Canadian task force will investigate the cause of the blackout and identify actions to prevent it from happening again. It will be headed by Energy Secretary Spencer Abraham and Canadian Natural Resources Minister Herb Dhaliwal.

President Bush said the power breakdown showed ''we need to modernize the electricity grid.'' But, he acknowledged, ''Something like this isn't going to happen overnight.''

NERC officials also said that as of late Friday afternoon, about two-thirds of the lost power had been restored throughout the affected region. At the peak, 61,800 megawatts of power had been lost; by 4:15 p.m. Friday all but 19,900 megawatts had been restored. No details about which areas were still without power were given.

The cause of the blackout remained unclear. Early reports had indicated the problem started in Canada, and another theory had the cause pinned down to eastern Michigan.

No one was sure.

Power grid experts were stunned at the broad reach of the blackout and the speed--a matter of seconds--with which it spread thousands of miles across New York and southern New England to the eastern sections of Michigan and into Canada.

''We never anticipated we could have a cascading outage'' of this magnitude and speed, said Michehl Gent, chief of NERC, the industry-sponsored organization charged with assessing the dependability of the nation's electric grids.

Precautions were supposed to have been put in place to prevent such a widespread domino effect, he said, vowing to ferret out what triggered the chain of events and to take corrective action.

If the problem began in Ohio or Michigan, as one theory held, it should never have reached Manhattan, complained New York Gov. George Pataki, adding that the grid was supposed to be designed to isolate such problems. ''That just did not happen,'' he said.

It may be days, or even weeks, before solid answers emerge.

Gent said that the answer was somewhere on the ''Lake Erie Loop''--a massive, troublesome transmission loop that encircles Lake Erie from New York to Detroit, into Canada and back to New York.

''That's the center of the focus. This has been a problem for years, and there have been all sorts of plans to make it more reliable,'' Gent said.

About the time power was disrupted at 3:11 p.m. Chicago time Thursday, technicians noticed a stunning development on the northern leg of the loop: 300 megawatts of electricity moving east abruptly reversed course, and within seconds, 500 megawatts of power suddenly were moving west.

Electricity flows on its easiest path, so it is believed the change in direction was caused by a sudden reduction in power somewhere on the line at the western end of the loop, investigators suggested.

''This was a big swing back and forth,'' said Gent, adding that throughout the grid system, power levels began to fluctuate. That caused generators and other systems to trip across the region to protect equipment.

More than 100 power plants, including 22 nuclear reactors in the United States and Canada, shut down, most automatically to protect themselves against power surge.

The whole process ''essentially took 9 seconds,'' Gent said. ''It happened very quickly.''

AP