Akron, Ohio-based FirstEnergy confirms that a generator near Cleveland went down two hours before the blackout and that three of its transmission lines subsequently shut down, two of them due to possible contact with trees. A control-room alert was also out of order. But a FirstEnergy spokesman says neighboring power companies faced similar glitches. Officials of American Electric Power, a Columbus, Ohio, company, and PJM, a Valley Forge, Pa., grid operator, confirmed their systems experienced routine failures before the blackout. These companies insist their problems had no big impact on their own systems, let alone neighboring grids. The president of International Transmission, a Michigan grid owner, questioned whether the Columbus and Valley Forge companies might have exacerbated minor local problems when relays cut off the flow of electricity between their lines and FirstEnergy’s, possibly overloading parallel circuits in Michigan, Canada and New York. American Electric Power and PJM say their connections to FirstEnergy cut out automatically to protect their systems from meltdowns, and note that power stayed on in southern Ohio, which is served by American Electric Power, and much of Pennsylvania, New Jersey and Maryland, PJM’s area. Experts say a series of minor events involving several companies may have caused the blackout, not problems at one utility. Analyst Hoff Stauffer says: “It was the perfect storm of electricity.”
