Putting Light on a Blackout

The morning after a crippling power outage, San Francisco was pretty much back to normal. Traffic lights, elevators and phones worked as usual. But even before the lights flicked back on up there, Southern California officials were asking themselves whether a blackout of similar scope could occur here.

They could not, of course, rule out human error of the kind that triggered the San Francisco outage. They could, however, boast of a system design that makes the region far less vulnerable to a blackout of the duration and expanse suffered by San Francisco.

Electricity was cut off to all of San Francisco for hours Tuesday when a Pacific Gas & Electric crew did not follow proper procedures in completing renovations at a substation south of the city. Crew members mistakenly left two grounding rods in place when turning circuits back on at the San Mateo substation. That short-circuited power lines to San Francisco from stations to the south and automatically shut down generating stations in the city, broadening the outage.

What made it more difficult to bring power back quickly is that San Francisco is on a peninsula that is served by a single corridor of overland power lines. When a series of glitches occurs as on Tuesday, there is no simple alternative distribution path. Contrast that with the Los Angeles area, where the municipally operated Department of Water & Power and the privately owned Southern California Edison use a complex distribution web fed by different power sources. When one section or line goes down, a brief outage will occur until another section compensates--unless, of course, a catastrophe like the 1994 Northridge earthquake occurs.

PG&E; is investigating the San Francisco accident; the California Public Utilities Commission will start a formal inquiry next week. There are questions of wide importance that need to be answered. Was there anything about how the errant power crew was trained that should be corrected? Is a backup source of power a realistic option for San Francisco?

That one false move by a utility worker can turn off the switch of a major city should give everyone pause.