Skip to comments.Experts Stumped on Cause of Huge Blackout
Posted on 08/15/2003 3:50:22 AM PDT by Gabrielle Reilly
A massive power blackout retreated stubbornly Friday as power officials struggled to understand why the historic outage spread in minutes through the northeastern United States and southern Canada. Lights flickered on and air conditioners restarted for some, but millions of others baked in stuffy rooms.
In New York City, where lights began to flicker on in parts of midtown Manhattan and other boroughs and suburbs before dawn Friday, millions faced a morning rush hour without subway service and no timetable for full restoration of power. In Michigan, some customers may have to endure a weekend without electricity. Everywhere officials urged residents, businesses and travelers to cope with the inconvenience.
(Excerpt) Read more at apnews.myway.com ...
While the actual blackout occurred at 4:11 p.m. Thursday, here are some key problems that occurred earlier that day:Excerpted from : http://www.ohiocitizen.org/campaigns/electric/2003/attention.htm
2 p.m. - FirstEnergys Eastlake Unit 5, a 680-megawatt coal generation plant in Eastlake, Ohio, trips off. On a hot summer afternoon, "that wasnt a unique event in and of itself," said Mr. DiNicola. "We had some transmission lines out of service and the Eastlake system tripped out of service, but we didnt have any outages related to those events."
3:06 p.m. - FirstEnergys Chamberlain-Harding power transmission line, a 345-kilovolt power line in northeastern Ohio, trips. The company hasnt reported a cause, but the outage put extra strain on FirstEnergys Hanna-Juniper line, the next to go dark.
3:32 p.m. - Extra power coursing through FirstEnergys Hanna-Juniper 345-kilovolt line heats the wires, causing them to sag into a tree and trip.
3:41 p.m. - An overload on First Energys Star-South Canton 345-kilovolt line trips a breaker at the Star switching station, where FirstEnergys grid interconnects with a neighboring grid owned by the American Electric Power Co. AEPs Star station also is in northeastern Ohio.
3:46 p.m. - AEPs 345-kilovolt Tidd-Canton Control transmission line also trips where it interconnects with FirstEnergys grid, at AEPs connection station in Canton.
4:06 p.m. - FirstEnergys Sammis-Star 345-kilovolt line, also in northeast Ohio, trips, then reconnects.
4:08 p.m. - Utilities in Canada and the eastern United States see wild power swings. "It was a hopscotch event, not a big cascading domino effect," said Sean OLeary, chief executive of Genscape, a company that monitors electric transmissions.
4:09 p.m. - The already lowered voltage coursing to customers of Cleveland Public Power, inside the city of Cleveland, plummets to zero. "It was like taking a light switch and turning it off," said Jim Majer, commissioner of Cleveland Public Power. "It was like a heart attack. It went straight down from 300 megawatts to zero."
4:10 to 4:25 p.m. - Power plants and high-voltage electric transmission lines in Ohio, Michigan, New York, New Jersey, and Ontario shut down.
In summary, this kinda 'came down' like a number of other large blackouts have come about - loss of a large generating plant or 'tie' lines into a relatively high-demand area, a cascading effect of 'overloaded lines' other lines/facilities that replace the lost line(s)/or generating capacity ...
As reference I would recommend the on-line resources to be found on the net that cover both the '65 North East Blackout and the '77 New York City blackout. In particular, the reports issued by the 'Federal Power Commission' at the time are particularly good at describing the events and causitive factors in the '65 and '77 blackouts.