The heat wave that triggered widespread blackouts around Southern California occurred as the Department of Water and Power underestimated how much power Angelenos would use at one time while overestimating the quality of its equipment, according to interviews and documents.
The record temperatures sent power usage to an all-time high of 6,165 megawatts -- an amount that shocked agency officials.
“They didn’t even believe our customers could ever put such a load on our system -- that we could even have energy use from our customers up to that kind of level,” said David Nahai, a DWP board member.
Until this week, the highest peak energy use was during a heat wave last summer, at 5,661 megawatts. DWP projections didn’t call for energy usage in L.A. to top 6,100 megawatts until four years from now.
But officials said several factors conspired to cause a surge in power use. A week of 100-plus-degree temperatures -- and record heat at night -- prompted many residents to run their air conditioners 24 hours a day.
Moreover, the DWP’s projections didn’t fully account for the increased energy use of today’s larger, highly electronic homes -- including the growing popularity of big-screen plasma TVs, which eat up about as much power as a large refrigerator and about a third the energy of a central air system.
Nationally, power companies are expecting a 50% increase in the power used by televisions as more people convert to more sophisticated sets.
“We were very, very surprised at the experience we were having over the weekend, which was the unbelievable demand,” Kim Hughes, a DWP spokeswoman.
DWP Commissioner Nick Patsaouras, an appointee of Mayor Antonio Villaraigosa, blamed the mayoral administration of James K. Hahn for moving money into the general fund that could have been used to upgrade DWP systems.
He said the utility’s staff had known for years that its equipment was outdated.
“We know staff knew for a long time,” Patsaouras said. “You know when equipment is bad.”
The DWP has not yet calculated the total number of customers who lost power. The greatest number of customers without electricity at any given time was 30,000, but the total number of those affected during the course of the heat wave was much higher.
Southern California Edison has said a total of 1.1 million of its customers lost power.
Edison, which serves 4.7 million customers over much of Southern California, had done a better job in estimating power use during the heat wave -- though that didn’t prevent widespread blackouts.
The utility expected up to 23,000 megawatts, and the peak was just below that, at 22,889 megawatts, said Ron Litzinger, senior vice president of transmission and distribution for SCE. Still, the demand was too much for 1,312 transformers, which overheated.
The experience has prompted Edison to reassess the way it plans for the energy needs of the communities it serves.
Edison forecasters said household consumption of electricity has gone up for the last several years. It used to be assumed that one megawatt could adequately serve 750 homes. Now that expectation has been adjusted to 650 homes. Not too long ago, Litzinger said, a megawatt could serve 1,000 homes.
As both agencies consider improvements in the wake of the heat wave, they agree the costs are going to be high. Both Edison and DWP have transformers that are 40 to 50 years old and will eventually need to be replaced. Parts of the utilities’ systems date to the ‘20s and ‘30s.
Edison has committed $9 billion to upgrade its systems over the next five years, and DWP’s 10-year plan called for a $2-billion investment from 2001 to 2010.
At the DWP, officials had felt confident that the utility’s system would hold up. For years, the utility had a record as one of the most reliable energy providers in the state.
But there had been some warning. After a costly and disruptive blackout last fall, the DWP board commissioned a detailed report on the state of the city’s electrical infrastructure.
That report, which was presented to board members in two parts last winter and spring, said the DWP could no longer carry on by simply fixing equipment as it broke down. Unless transformers, lines and other integral parts of the system were replaced, the report said, more blackouts would occur.
DWP board member Patsaouras said the city is now paying the price for decades of neglect to the system, and change won’t come overnight.
“You have equipment that has a life expectancy of 20 to 25 years and has been on the power poles since the ‘30s,” Patsaouras said. “Blaming the heat is baloney. You have heat in Palm Springs, and the transformers don’t burn every summer.” As a result of the report after last fall’s blackout, the agency appropriated an additional $30 million for upgrades this year.
While most power had been restored by Thursday, some customers remained concerned.
Although the power is back on at Eva McCoy’s home, the Beverlywood resident is bracing for the worst. She, her husband, John, and their 5-year-old daughter Sophie lived without electricity for three days during the peak of the heat wave until it was finally restored Wednesday morning. But she said the DWP worker who repaired the transformer that distributes electricity to eight homes on her block told her and her neighbors that if usage climbs, they will lose power again.
“He said it was a temporary patch. They need to replace it with a stronger transformer,” McCoy said Thursday. “We could lose power any time. It could happen tonight, tomorrow or this weekend.”