So far this fire season, the utility has pre-emptively shut off power to nearly three million people in central and Northern California, some for as many as five days. PG&E has said the blackouts help guard against fires ignited by the sparks created when windblown tree branches hit live power lines. But critics, including state and local government officials, have said PG&E has done a poor job of warning residents about the shut-offs, which have had a disproportionate impact on low-income families that cannot afford generators or batteries, and on older and sick residents who rely on electric medical devices.

For some, the blackouts have amounted to “a big screw-you,” said State Senator Bill Dodd , a Democrat whose district includes Napa and Sonoma, during the hearing on Monday.

PG&E has warned that it might have to employ such blackouts for up to a decade while the utility makes up for deferred maintenance. The chief executive, Bill Johnson , told lawmakers on Monday that it aimed to move faster and reduce the number of affected customers by one-third or more starting next year. To do so, it is installing backup energy systems like microgrids, underground power lines and weather cameras.

“It’s not acceptable to me to have another year like this,” Mr. Johnson said.

Not everyone is willing to wait. State Senator Mike McGuire, a Democrat who represents the area where the Kincade fire burned 174 homes recently, is one of many lawmakers who have said the state should consider offering a “public option” for electricity. PG&E has already stumbled twice, he said on Monday, with a deadly 2010 gas explosion and several devastating fires in the last two years.

“I think we’re on our third strike,” Mr. McGuire said. “They’ve failed us too many times.”

Mr. Johnson acknowledged that state lawmakers and regulators had the power to revoke PG&E’s franchise but said those efforts would have to overcome legislative and constitutional obstacles.