Blackout a Reminder of Power Grid Vulnerabilities and a Sign of Things to Come

A blackout that swept across parts of the Southwest and Mexico apparently began with a single utility worker and a minor repair job.

How it then rippled from that worker in the Arizona desert, to southern California and across the border, plunging millions of people into darkness, has authorities and experts puzzled, especially since the power grid is built to withstand such mishaps.

However it spread, Thursday’s outage was a reminder that the nation’s transmission lines remain all too vulnerable to cascading power failures.
“There are a lot of critical pieces of equipment on the system and we have less defense than we think,” said Rich Sedano at the Regulatory Assistance Project, a utility industry think tank based in Montpelier, Vt.

There have been several similar failures in recent years. In 2003, a blackout knocked out power to 50 million people in the Midwest and the Northeast. And in 2005, a major outage struck the Los Angeles metropolitan area.

That same year, Congress required utilities to comply with federal reliability standards for the electricity grid, instead of self-regulation. Layers of safeguards and backups were intended to isolate problems and make sure the power keeps flowing.

But that didn’t happen on Thursday.

The Arizona Public Service Co. worker was switching out a capacitor, which controls voltage levels, outside Yuma, Ariz., near the California border. Shortly after, a section of a major regional power line failed, eventually spreading trouble further down in California and later Mexico, officials said.

And the lights began to go out in a border region of roughly 6 million people.

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