The ISO said it needed to shed about 400 megawatts of power demand to avoid overloading the system. Southern California Edison said circuits had been shut in about 60 communities, including Beverly Hills, Long Beach, Anaheim, West Hollywood and Santa Monica. The ISO, struggling throughout the day to avert blackouts, nevertheless warned they were likely, citing temperatures of 95 to 100 degrees Fahrenheit throughout much of the state for a second day.
Air conditioning accounts for about a third of California's electricity demand on hot days.
Some 5,600 megawatts of emergency hydro-electricity imports from dams in the Northwest helped keep the lights on through most of the day, but ultimately failed to meet demand the ISO predicted would peak Tuesday at about 35,827 megawatts. The ISO ordered rolling blackouts to about 225,000 customers for about an hour Monday evening when demand overwhelmed supply. It was the fifth time this year blackouts were ordered as California struggles with its worst ever energy crisis, the result of an aging electrical system unable to keep pace with the demands of the state's 34 million residents. All rights reserved. Republication or redistribution of Reuters content is expressly prohibited without the prior written consent of Reuters.