How a phone alert might have saved California's power grid

Amid a historic heat wave in California, residents were urged to conserve energy in order to protect the state's power grid. And it appears a mass phone alert, sent to millions of Californians, might have done the trick. 

At 5:48 p.m. Tuesday, California ISO declared Energy Emergency level 3, meaning rolling power outages were imminent.

The alert read "Extreme heat is straining the state energy grid. Power interruptions may occur unless you take action. Turn off or reduce nonessential power if health allows, now until 9pm."

Level 3 is the state's grid operator's highest category of an energy emergency.

According to California Gov. Gavin Newsom, the alert was sent to 27 million phones and within 45 minutes the state saw a roughly 2,600-megawatt reduction in usage.

"What folks were able to accomplish last night with conservation of some 4,000-megawatts of conservation is extraordinary and had it not been for the efforts of literally millions of Californians, just to turn down a light, turn down a thermometer, not use a large appliance, we would not be in the position we are today," the governor said Wednesday during a press conference in Beverly Hills.   

As the heat wave continues, the state set a power-demand record on Tuesday, with Cal-ISO reporting a peak electricity usage of 52,061 megawatts, topping the 2006 record of 50,270 megawatts.

Cal-ISO is predicting a peak usage Wednesday of 51,164 megawatts, with Thursday's prediction at 51,318. A Flex Alert urging conservation will again be in effect from 4 to 9 p.m. Wednesday, and Cal-ISO issued an Energy Emergency Alert 2 Wednesday afternoon, warning utilities statewide that shortages in supply could occur, while urging residents again to step up conservation efforts.