The Northeast Blackout #onthisday #history
11An overloaded high voltage powerline in Ohio sagged into overgrown trees and tripped causing its load to transfer to other transmission lines, in turn tripping their breakers…this started to cause a series of shutdowns and trips throughout the grid.
A bug in the monitoring system at the command center prevented alarms from going off and so technicians reacted slowly. Within minutes a manageable series of problems became a cascade of failures knocking out most of Ohio’s grid before it could be disconnected from the rest of the regional grid. This caused it to draw a massive amount of power from the neighboring Michigan grid.
Within 30 seconds Michigan’s grid was down too, disrupting power supply across most of the North East and within 4 seconds of this, the Black Out was mostly in effect as hundreds of power stations across the region shut down as a protective measure.
An over 200 page report into the incident laid the blame mostly on the Ohio power provider who had failed to upgrade their computer systems, were short staffed and did not trim the trees near their lines.
This behavior was in turn blamed on deregulation and lack of enforcement: before 2005 many of the rules for the power companies were essentially voluntary as federal and state regulators didn’t have enforcement powers and couldn’t issue fines. This was addressed in 2005 by a new set of laws (at least that was the promise and hope).