Hot days could bring power woes to California : LUSENET : Grassroots Information Coordination Center (GICC) : One Thread

Article last updated: Monday, April 03, 2000 4:12 AM MST STEPHEN J. PRINGLE -- Staff

Hot days could bring power woes Program will pay users to limit use


California may face power outages during peak demand periods if the coming summer is a scorcher, according to managers of the state's electrical transmission system.

Because construction of new power plants hasn't kept pace with the state's booming economy and population, the California Independent System Operator may need to pay large customers to use less electricity during critical periods.

The non-profit corporation, created in 1998 as part of utility deregulation, oversees California's electrical transmission grid -- high tension wires that allow power to be imported into the state and transported where it's needed.

Even if temperatures are normal, overloading of a substation in Tracy could lead to brownouts in the East Bay and San Joaquin Valley, according to a report to the Independent System Operator's board of directors.

The outlook in San Mateo County and the peninsula is more optimistic, thanks to transmission upgrade projects and generator repairs.

If thermometers soar across the West this summer, it's possible that California won't be able to import all the power it needs from the Northwest and Southwest, the March 9 report said.

There's only a 5 to 10 percent chance that temperatures will get hot enough to create the worst-case demands studied. But if a heat wave strikes, watch out.

"In peak demand periods, it could be a stretch," said economist Marvin Feldman, whose San Francisco consulting firm, Resource Decisions, advises utilities and independent generators. "A long hot spell, a real heat wave, together with any loss of generating capacity, like if one of the nuke plants is down, that could really put a crunch on."

Peak demand for electricity in California could be as high as 48,940 megawatts. The state's power plants can only deliver 40,300 megawatts. If demand is high throughout the West, it's estimated that as little as 6,500 megawatts of electricity would be available to import.

The result: unmet peak demands totalling at least 2,140 megawatts -- enough of a shortage to leave about 14 cities the size of Livermore in the dark.

To prevent that from happening, the Independent System Operator wants the ability to quickly reduce load on the grid by as much as 1,800 megawatts. It's accepting bids in two separate programs that would pay electricity users to cut use before shortages occur. Board members say it's unclear how much the programs will cost until the bids are accepted.

Individual utilities also have such programs in place. Pacific Gas & Electric Co., for instance, has the ability to ask large customers to curtail 450 to 500 megawatts of load in the Bay Area.

California has to depend on imports during peak demand periods because large power plants now being planned or built by private companies hoping to cash in on deregulation haven't come on line yet, Feldman said. Meanwhile, demand is rising, and deregulation has put more stress on transmission networks.

"It's actually a double whammy," Feldman said. "Everyone who was in a position to build power plants was in a wait-and-see mode, so new capacity won't be on line for a while. The marketing of power does put more stress on the transmission system in general, because rather than just selling in your territory, you can be selling into other areas that are remote."

The first wave of new power plants approved under utility deregulation aren't scheduled to begin coming on line for two years.

Further complicating matters are California's older power plants, which suffer from reliability problems. According to a California Energy Commission study, 61 percent of the electricity produced by oil and gas-fired plants comes from facilities that are more than 30 years old.

In the last year, the Energy Commission has approved four new power plants capable of producing 2,923 megawatts of electricity. Two of the plants, including the 880 megawatt Delta Energy Center approved Feb. 9, are located in Pittsburg.

The Energy Commission has received or expects to receive applications to build another 20 power plants in the state. Altogether, the 24 new plants on the horizon are expected to cost more than $7.25 billion and be capable of producing more than 15,000 megawatts of electricity.

For now, California must rely on imports to handle peak demand. Even if temperatures are normal this summer, the state would have to import about 8,425 megawatts to meet anticipated peak demand of 46,250 megawatts and maintain a 6.5 percent reserve capacity.

That's not necessarily a problem -- the state was importing 8,378 megawatts when demand peaked on July 12 last year. But the need to import nearly one-fourth of the state's electricity during such peaks illustrates how far construction of new power plants has lagged behind demand.

Having to move that much electricity around can create bottlenecks in the grid. Of particular concern is a transformer in Tracy that will probably have to carry more electricity than it's rated to handle. A crash-program to fix the problem isn't expected to be in place until 2002, and the East Bay and San Joaquin Valley will be more susceptible to brownouts until then.

To keep power flowing in the East Bay and San Joaquin Valley, officials are considering letting the Tracy transformer run above its rated capacity.

"We will use all the generating resources available to us in the San Francisco Bay Area, along the (Sacramento River) Delta, as well as the Sacramento and Stockton areas, and as far south as the Monterey Peninsula, to back off the transformer," said Jim Detmers, director of operations, engineering and maintenance for the Independent System Operator.

Detmers said that under a proposal still being studied, the transformer might be allowed to handle up to 10 percent more electricity than its rated capacity. The transformer would literally run hotter, and operating temperatures would be monitored to "make certain we have levels that don't decrease the life expectancy of the transformer."

Another way to take stress off the transformer is to pay large industrial customers to cut electricity use when loading becomes excessive.

The closer the customers are to the substation, the more relief such programs provide. While it's prudent to have the programs in place, Detmers said he's confident they won't actually be needed if temperatures are normal.

-- Martin Thompson (, April 04, 2000

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