California heat wave continues; officials ask public to cut their power use with San Onofre out of commission

People enjoy the view from a lifeguard structure as the sun sets at Seal Beach, south of Los Angeles on July 9, 2012.
People enjoy the view from a lifeguard structure as the sun sets at Seal Beach, south of Los Angeles on July 9, 2012.
Frederic J. Brown/AFP/Getty Images

Californians sweltering in a heat wave are being urged to reduce their power consumption — including that air conditioning you may desperately want to be using. The "Flex Alert" continues through the weekend in order to maintain electrical reserves and avoid possible outages.

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

It's also the summer's first real electric test without the help of the San Onofre nuclear power plant due to safety concerns at that location. 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.

As was the case Thursday, an excessive heat warning issued by the National Weather Service to indicate oppressively high temperatures will be in force today from 11 a.m. until 8 p.m. in the San Gabriel, San Fernando and Santa Clarita valleys and the mountains of L.A. County — both the San Gabriels and Santa Monicas. The warning reflects that "the combination of hot temperatures and high humidity will combine to create a dangerous situation in which heat illnesses are possible," according to the NWS.

The NWS forecast highs today of 90 in downtown L.A.; 91 in Anaheim; 92 in Long Beach; 93 in San Gabriel; 98 in Pasadena; 100 in Burbank; 107 in Woodland Hills and Saugus; and 108 in Palmdale and Lancaster. Temperatures are expected to be a few degrees lower Saturday and fall some more over subsequent days.

Valleys and inland areas have been baking all week. 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.

An unexpected outage at the Ormond Beach Generating Station, a gas-fired power plant in Ventura County, was partially responsible for triggering the Flex 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.