California Leaders Credit Cellphone Alert for Sudden Conservation

BEVERLY HILLS, Calif. — Standing in the shade of a tall hedge outside the Beverly Hilton hotel and sweating in the relentless heat, Gov. Gavin Newsom of California said on Wednesday that emergency cellphone alerts the evening before that had urged Californians to conserve energy were instrumental in pulling the state’s heat-strained power grid back from the brink.

The alert to about 27 million cellphones — accompanied by a blaring alarm of the sort that precedes Amber Alerts and natural disaster warnings — was followed within moments by a major drop in use, roughly 2,600 megawatts within 45 minutes, according to state energy use figures.