Local Utilities Juggle Energy Supply to Beat the Heat

Across the street from the Home Depot store in Alhambra, four men in slacks and shirt sleeves spent Wednesday in a windowless, cavernous control room quietly marshaling the power of Hoover Dam, nuclear reactors and even a few generators hooked up to jet engines.

The crew at the Southern California Edison Energy Control Center kept up its coolheaded juggling of power sources to meet another day of surging electricity demand. Thanks to them, air conditioners were still running during a blistering heat wave.

Electricity usage climbed even though temperatures fell slightly below Tuesday’s all-time high readings in parts of the Southland. Power consumption records were set by both Southern California Edison and the Los Angeles Department of Water and Power on Wednesday.

James D. Dyer, Edison’s grid dispatch manager, said that after a few days of hot weather, the heat trapped in buildings makes air conditioners work harder. “When it starts warming up, buildings don’t cool off as much at night. When it’s in the mid-70s at night, we know we’re in trouble,” he said.

Thus the surging demand for electricity probably will continue for a few days even as temperatures creep down into the double-digit range this week.

Fortunately, Edison and DWP anticipated the summer spike in demand and were ready with electricity from far and wide. Southern Californians draw power from sources as far away as Canada and New Mexico.

Through vast networks of power lines, electricity is bought and sold across regions as prices and seasonal demands dictate.

The Pacific Northwest, for instance, tends to sell power to Southern California in the summer, when its usage is lower. Those in cooler states often buy power from Southern California producers in the winter, when their usage rises along with heating needs.

Utilities like Edison always use a mix of locally produced and imported power. Edison’s own network of 17 generating stations supplies about 40% of its power needs, and it buys about a quarter of its power from other utilities.

The utility buys about a third of its supply from independent producers, such as meatpacking plants that produce electricity with the steam generated from food processing, Dyer said.

The mix of power from local and faraway sources doesn’t change much in high demand periods such as this week’s heat wave, Dyer said. At some Edison plants, Pratt & Whitney jet engines are hooked up to generators and fired up when demand rises.

In the Alhambra control room, the staff constantly monitors the outside temperature and power demand, turning up generators as power is needed, or getting on the phone to order more power from out-of-state providers like Hoover Dam.

Edison’s electricity usage Wednesday topped 19,000 megawatts for the first time. Tuesday’s usage of 18,735 megawatts had broken a record set in August 1992.

The DWP’s Wednesday usage was 5,433 megawatts, passing a record of 5,366 megawatts set Tuesday. Tuesday’s DWP usage broke a 7-year-old record, said spokeswoman Karen Shepard-Grimes.

While electricity demand should remain high this week, relief from the heat is on its way.

Temperatures should cool slowly into the weekend as the high pressure ridge lingering over the coast breaks up to let a sea breeze penetrate inland, meteorologists said.

“It will still be hot but not as hot,” said John Sherwin, a meteorologist at WeatherData Inc. “[And] there will probably be fog at the coast tomorrow morning.”

Sherwin predicted that by the weekend temperatures will dwindle to the 80s downtown and the 70s along the coast.

On Wednesday, the mountains and deserts surrounding the Los Angeles Basin got a pittance of shade. Moisture drifted up from Mexico and bloomed into cumulus clouds that towered above the lowland smog.