What caused major US/Mexico outage? Inquiry under way

Would a smarter, more up-to-date electricity grid have prevented the power outage that left more than one million people in southern California, Arizona and parts of Baja Mexico without electricity this week? That seems like a no-brainer, but we might expect more detailed answers into the hows and whys now that a joint investigation into the incident has been launched.

The joint inquiry was announced today by the Federal Energy Regulatory Commission (FERC) and the North American Electric Reliability Corporation (NERC).

The outage apparently began around 3:30 pm on Thursday, Sept. 8, around the time an employee of the Arizona utility APS was doing work in a substation near Yuma. “Operating and protection protocols typically would have isolated the resulting outage to the Yuma area,” APS reported later on Thursday. “The reason that did not occur in this case will be the focal point of the investigation into the event, which already is under way.”

Crews were still working Friday to re-energize the 500-kilovolt transmission line at the center of the outage. As of Friday afternoon, all but 200 megawatts of the total 4,300 megawatts of power supply lost had been restored.

FERC and NERC will look into the matter with help from the US Department of Energy and other federal agencies, the California ISO, the Western Electricity Coordinating Council, California and Arizona state regulators, and the companies involved.

“This inquiry is an effective way for us to protect consumers and ensure the reliability of the bulk power system,” said Jon Wellinghoff, FERC chairman.