As Heat Soars in California, Power Supply Is Strained

By RANDAL C. ARCHIBOLD
Published: July 25, 2006
http://www.nytimes.com/2006/07/25/us/25power.html?th&emc=th

LOS ANGELES, July 24 — Days of heat and humidity have driven demand for electricity to record highs in California and other states. If people cannot take the weather anymore, neither can transformers and other equipment, which have sputtered and shorted out and left tens of thousands of people without power.

The authorities in California, which is normally cooler and drier this time of year, warned on Monday that the high demand could lead to rolling blackouts, a dreaded term here that brings reminders of the widespread blackouts during the energy crisis of 2000 and 2001.

Officials issued an alert under which certain large businesses voluntarily agree to curtail power use in times of unusually high demand. The California Independent System Operator, which manages the power grid, said the operating reserve of electricity had dipped to around 5 percent, well below the optimal 15 percent or more.

Gov. Arnold Schwarzenegger ordered state agencies to reduce electricity consumption by 25 percent, acting on a prediction from the state’s power grid managers that demand would peak at 52,000 megawatts, a mark they had not expected to reach until 2011. Demand peaked at 50,270 megawatts at 2:44 p.m. Pacific time, breaking the record of 49,036 megawatts set last Friday.

In other parts of the country, thunderstorms have compounded problems, leaving more than 200,000 people in the St. Louis area without electricity, some of them since Wednesday. Officials at Ameren Corporation, the utility there, said they had brought in some 4,000 employees and contractors from several states to work around the clock to restore power.

Thousands of people in Queens entered a second week without power after equipment failures at one point left some 100,000 people without electricity.

Unlike a few years ago, the culprit behind the rash of power failures in most cases this summer is equipment, some of it old but generally unaccustomed to running at such high demand over such a long stretch of hot and humid days, more than two weeks in some places. Temperatures and humidity were lower Monday than they were over the weekend but remained above normal.

Enrique Martinez, the chief operating officer of the Los Angeles Department of Water and Power, likened the equipment problems to driving a car 100 miles an hour nonstop for long periods.

“If you continue to do it, it’s going to break down,” said Mr. Martinez, whose utility was trying to restore power to 9,000 homes and businesses around the city, down from 20,000 customers who had lost power over the weekend. Southern California Edison, which supplies power to suburban cities, said 17,000 customers remained without power.

Mr. Martinez spoke at a news conference in the San Fernando Valley, where the temperature in the Los Angeles neighborhood of Woodland Hills reached 119 on Saturday, a high for Los Angeles County, according to the National Weather Service’s preliminary check of records.

The heat wave in Northern California, which drove temperatures to around 90 degrees Sunday in the normally cool and foggy San Francisco, has been blamed for several deaths, and 900,000 households lost power at some point over the weekend and into Monday. Brian Swanson, a spokesman for Pacific Gas and Electric, which serves Northern California, said that by noon Monday, 50,000 customers were still in the dark.

The authorities in Stockton, Calif., are investigating the death of a patient at the Beverly Healthcare convalescent home, from which about 200 residents were evacuated Sunday after the air conditioning apparently malfunctioned as the temperature hit 115 degrees.

The power failures have hit Southern California’s valley areas particularly hard, but the blackouts also affected Hollywood, the West Side and other parts of the city. In some cases they had the skipping effect of a tornado: a few houses on a street went dark, or even just parts of houses, while others continued to blast air conditioners.

One of the busiest Web sites, MySpace, based in Santa Monica, Calif., said the power failures, along with problems with its own backup generators, had shut down full use sporadically over the weekend.

Relief appeared on the way, with temperatures expected to fall to the usual 70’s and 80’s beginning Tuesday.

But the electricity system, experts have warned, remains vulnerable, especially in Southern California.

The North American Electric Reliability Council, an industry group, said supplies nationwide were tighter this summer than last, and in a report in May singled out Southern California and southwestern Connecticut as particular areas of concern.

Still, despite most power grids having run at or near record demand this past week, most power failures in the country this summer have come from problems with the distribution system, not with the supply. Local utilities typically learn of problem transformers and cables only as they fail, said Stan Johnson, who monitors power grid trends for the council.

“It does raise some very serious questions that need to be answered, if we are putting sufficient money in upgrading the distribution system,” Mr. Johnson said.

But Mr. Martinez said the utility had been keeping pace with repairing and replacing equipment and called this heat wave, with its severity and length, a particularly unusual strain.

Maintenance crews working on transformers and other equipment are “bringing more new ones in as they can,” he said. “They weren’t designed to deal with a heat wave like this.”

Carolyn Marshall contributed reporting from San Francisco for this article, and Cindy Chang from Los Angeles.