US and Canadian investigators reported that plant shutdowns and an overburdened transmission grid owned by FirstEnergy Corp. (Akron, OH) as the primary cause of August's massive blackout that left 50 million people in the dark. The US Department of Energy (DOE, Washington, DC) government task force released the results of a three-month investigation into the power outage that cascaded across eight US states and Canada.
After FirstEnergy's EastLake plant unexpectedly shut down on August 14, 2003, other problems quickly followed on its transmission grid, the 134-page report said. The loss of FirstEnergy's Sammis-Star line triggered the cascade because it shut down the 345kV path into northern Ohio from eastern Ohio. That instantly created major and unsustainable burdens on lines in adjacent areas.
The report also cited "inadequate situational awareness" by employees of FirstEnergy, who were unaware that line-monitoring software was not functioning. Another contributing cause of the blackout was FirstEnergy's failure to trim trees that short-circuited three of its high-capacity power lines in Ohio. The report also focused on how the Midwest power grid operator lacked real-time information about what was happening to FirstEnergy's power lines, which hindered attempts to contain the outage.
It found that FirstEnergy violated four specific voluntary standards set by the North American Electric Reliability Council, and said the Midwest grid operator violated two such standards.
