California Heat Wave Prompts Call For Power Conservation

LOS ANGELES (AP) — Californians sweltering in a heat wave are being urged to reduce power consumption, including air conditioning, through the weekend to maintain electrical reserves and avoid the possibility of outages.

The California Independent System Operator, which manages most of the state's grid, said a so-called Flex Alert will be in effect from Friday through Sunday evening, as hot temperatures are compounded by rising humidity.

Record-breaking highs for the date were recorded Thursday in several Southern California areas. Lancaster's 109 degrees broke a 1980 record of 106. The Woodland Hills area of Los Angeles also reported 109 and Sandberg in the Antelope Valley had 98. Several desert areas had their warmest lows for the date. Palm Springs reported a low of 89, 3 degrees above the 2003 record.

Valleys and inland areas have been baking all week, bringing the summer's first real test of electrical supplies without the help of the San Onofre nuclear power plant.

The twin-reactor generating station on the coast between San Diego and Los Angeles has been offline all year since a small radiation leak from a steam tube led to the discovery of more extensive problems.

An unexpected outage at the Ormond Beach Generating Station, a gas-fired power plant in Ventura County, was partially responsible for triggering the alert because it took out 775 megawatts of energy from the grid, Cal-ISO said.

Electrical demand, particularly from so many air conditioners in operation at the same time, poses a strain on components of distribution systems such as power lines and transformers.

The call for conservation was echoed by utilities such as Southern California Edison, which serves an area with about 14 million people, and the Los Angeles Department of Water and Power, which supplies the nation's second-largest city.

The Flex Alert calls for voluntarily cutbacks on energy use between 11 a.m. and 6 p.m. to prevent reserves from falling to emergency levels. The first stage of California's three emergency levels is triggered when operating reserves are forecast to fall to between 6 percent and 7 percent.

(Copyright 2012 The Associated Press.)