A spokeswoman for the California Independent System Operator, which operates the state's power grid, says blackouts in some areas of an hour or more seem almost inevitable. Less power is available today to import from other states, ISO spokeswoman Stephanie McCorkle tells GlobeSt.com, compounding the problems caused by soaring temperatures and inactive plants.

More than 100,000 owners from San Francisco to San Diego lost power yesterday. About 40 communities in the LA-area alone were hit with blackouts that ranged from a few minutes to more than an hour. "Today looks like it will be more severe," McCorkle says.

Monday's outages snarled traffic in several neighborhoods because stoplights couldn't work, while hundreds of businesses were forced to close because they didn't have electricity to operate their lights or cash registers. There were no reports of injuries or looting, though some office workers found themselves trapped in elevators.