Despite billions spent upgrading its grid, Pacific Gas and Electric Co. still suffers more blackouts than California's other big utilities, state records show.

And blackouts in PG&E territory tend to last longer than they do elsewhere in California.

The causes typically aren't as dramatic as the June 5 underground fire in San Francisco, which shot flames 30 feet into the air above a manhole and knocked out power to 8,600 customers. Most of the blackouts are caused by rain or wind.

But they add up.

Last year, the average PG&E customer lost power for almost seven hours, according to records kept by the California Public Utilities Commission. That is the utility's worst performance in the past 10 years.

For comparison, the typical Southern California Edison customer went without power for almost two hours in 2008. San Diego Gas and Electric customers spent just under an hour without electricity.

Representatives of San Francisco's PG&E blame the weather and geography.

California's other utilities are smaller than PG&E and don't cover as much rural, remote and rugged terrain, they say. And last year's numbers were skewed by one of the state's worst winter storms in years, which slammed PG&E territory in Northern and Central California but didn't pack the same wallop down south. Take away the big storms, and PG&E performs about as well as the national average, the utility says.

"There's a lot more exposure to weather, to natural events here," said Mark Johnson, PG&E's vice president for electrical operations and engineering. "A lot of it is driven by topography, your ability to get to the location (of the problem). If you have to drive long distances to get there, that's going to affect the outage duration."

Critics not swayed

The utility's critics say those explanations aren't enough. For years, blackouts have been a source of friction between customers, politicians and PG&E, fueling efforts in San Francisco, Davis and elsewhere to break away from the company and switch to public power.

"They don't give us the service we've been paying for - and we're paying for top-notch service," said Mindy Spatt, spokeswoman for The Utility Reform Network watchdog group.

Blackouts can be either a brief annoyance or a serious problem. The underground fire June 5 in San Francisco's Tenderloin district cut power to Toan Nguyen's restaurant just after noon, while diners waited for their food.

"Lunch is always crowded," said Nguyen, manager of Splash Cafe & Restaurant on Ellis Street. "We had the gas grill, so we filled the orders, then we had to close."

The power stayed off until 6 p.m. "As a business owner, you're not happy about it," he said. "When the power's out, no one wants to come to your business, and there's nothing you can do about it."

On average, PG&E customers lost power 1.6 times in 2008, according to state data. That's higher than Edison's average of 1.1 outages per customer, and three times higher than SDG&E's average, 0.5 blackouts per customer.

But last year, PG&E had to deal with a major January storm that knocked out power to roughly 2 million customers throughout Northern and Central California.

On par with nation

Take away the major storms, and the typical PG&E customer spent 2.8 hours without power last year. While that's still worse than the state's other large utilities, it appears to be on par with the national average. A study last year from Lawrence Berkeley National Laboratory found that among utilities that track blackouts lasting longer than five minutes - the standard used by PG&E - the average was 2.8 hours.

In addition, PG&E says its performance within San Francisco is improving. Since 2007, the company has spent more than $200 million improving its distribution network within its hometown. The amount of time San Franciscans went without power dropped 43 percent from 2007 to 2008, according to the company's data.

PG&E also has asked state energy regulators for permission to spend an extra $2 billion on upgrading its grid in the next seven years. That program could cut the blackout duration rate for all PG&E customers by 25 percent, according to the utility. The money would come from customers' electric bills.

"At the end of the day, we realize that our customers and other stakeholders are going to have the final say on how well the system is performing," Johnson said.