PG&E’s blackout record is getting better — no, seriously

A traffic control officer directs traffic during a blackout in San Francisco on Dec. 20, 2003, when a fire at a PG&E substation knocked out electricity to 120,000 customers. Despite Friday’s blackout, which affected 95,000 customers, PG&E’s record on power outages is improving. less A traffic control officer directs traffic during a blackout in San Francisco on Dec. 20, 2003, when a fire at a PG&E substation knocked out electricity to 120,000 customers. Despite Friday’s blackout, which ... more Photo: KIM KOMENICH, AP Photo: KIM KOMENICH, AP Image 1 of / 52 Caption Close PG&E’s blackout record is getting better — no, seriously 1 / 52 Back to Gallery

Hard as it may have been for San Franciscans to believe Friday, Pacific Gas and Electric Co. has made steady, substantial progress in cutting the number and length of blackouts that its customers endure.

Stung by a series of outages and dramatic equipment failures in its San Francisco hometown — including a 2003 substation fire that cut power to one-third of the city — PG&E spent the last decade upgrading its equipment.

And that effort has produced results.

The average PG&E customer lost power 1.02 times in 2016, according to data compiled by the utility. In 2006, blackouts hit the average PG&E customer 1.45 times.

Similarly, the average customer lost power for 109 minutes in 2016. While more than an hour and a half may sound like a long time, it’s a big improvement from 2006, when the average PG&E customer went without electricity for 3¼ hours.

Those figures exclude major weather-related events.

The statistics may come as cold comfort to those in the 88,000 San Francisco homes and businesses that lost electricity in the blackout that started just after 9 a.m. Friday.

PG&E blamed the outage on a fire at an electrical substation that the utility planned to refurbish next year.

“We’ve identified it as a substation that needed to be updated,” said Barry Anderson, PG&E’s vice president of electric distribution, at a news conference Friday. “It just is a case where the equipment failed before we could get to the update.”

While more public attention has focused on PG&E’s natural gas network in the wake of the deadly 2010 San Bruno explosion, the utility’s electricity infrastructure also has a history of highly visible failures.

In June 2009, a power line from the 1920s melted inside a vault beneath Polk and O’Farrell streets, starting a fire that shot flames 30 feet into the air and knocked out power to 8,600 customers.

In August 2005, a transformer exploded beneath a sidewalk in the city's Financial District, shattering windows and severely burning a woman who was walking nearby.

And in December 2003, a fire in a Mission District substation blacked out large swaths of the city, with some customers waiting more than 24 hours for electricity to return.

But PG&E has been swapping out old equipment and adding new gear that can spot and isolate blackouts quickly. As a result, the number and duration of outages striking PG&E’s system have declined.

PG&E use to consistently suffer more blackouts than the state’s other large, investor-owned utilities, Southern California Edison and San Diego Gas & Electric. But, in 2015, the latest year for which data from all three companies are available, PG&E had improved its standing compared to its corporate peers.

In 2015, Edison experienced blackouts at a rate of 0.92 per customer, slightly worse than PG&E’s performance of 0.87 per customer. The San Diego utility, meanwhile, reported 0.53 per customer that year.

Edison’s average customer lost power for 115 minutes in 2015, while SDG&E’s average customer went without electricity for 58 minutes. PG&E’s average customer lost electricity for 96 minutes.

David R. Baker is a San Francisco Chronicle staff writer. Email: dbaker@sfchronicle.com Twitter: @DavidBakerSF