When was the biggest outage in North America?

August 14, 2003.  At the time it was the WORLDS second largest blackout in history.  50 million people in southeast Canada and eight Northeastern U.S. states were without power for two days to a week due to an untrimmed tree, human error and a software bug.  265 power plants shut down leaving 11 people dead and $6 billion in damages.  Incidents like this reminds us all of the social responsibility that we have to play our role in reliably delivering this essential energy source.
 
Here is the order of events as it occurred: 1 

1. Tree trimming was not done sufficiently in stretches of various transmission line easements
2. 12:15PM:  The alarm system at FirstEnergy’s control room failed due to a software bug 2
3. The system operators in Ohio were not aware of an overloaded transmission line and the need to re-distribute power
4. 2:02 PM:  An overloaded transmission line sagged and made contact with trees
5. As current found other paths to their loads more major transmission lines began to overload and fail
6. Power plants began to disconnect to protect themselves from a collapsing grid
7. 4:13 PM:  The final cascading failure of grids and power plants stops leaving 265 power plants shut down, 50 million people out of power, 11 people dead and $6 billion in damages.
8. Power is restored 2 days later except for some areas which took a week

 
Due to technical and human error what would have been a manageable local blackout cascaded into massive widespread outage.  Two years later the Energy Policy Act of 2005 was approved which required a non-governmental, self-regulatory organization to develop and enforce compliance with mandatory reliability standards to prevent this from happening again.  Having learned from our mistakes the National Electric Reliability Council 3 or NERC was born 4. 

World Record Outages

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