July 22, 2004
Max Jarman and Dennis Wagner
The Arizona Republic
Electrical substation fires like those that struck the Valley's power grid this month are not unheard of, and some experts suggest they are telltale signs of a system that is overstrained, aging and spottily maintained.
Cities such as Chicago and Los Angeles, for example, have seen their power grids struck by substation fires similar to those that hit the Valley.
In a report last month by the London-based Economist Intelligence Unit, the analysis firm declared, "Blackouts (in the U.S.) become more commonplace as the country's antiquated power grid fails to meet demand. . . . The problem is that new transmission towers and new transformers cost billions, yet the industry is only interested in making the investment if regulators guarantee them rate increases to cover their costs."
In Chicago, a string of substation outages and fires in 1999 and 2000 prompted the Illinois Commerce Commission to order an investigation into Commonwealth Edison's power infrastructure. The probe found systemic maintenance flaws throughout the system. Among the lapses: a fire caused by a metal washer left in a transformer by the manufacturer or a maintenance worker.
The commission recommended a fine, but Commonwealth avoided it by rolling the matter into a settlement of several issues, said Beth Bosch, commission spokeswoman.
There are no indications so far that the Valley's power companies, APS and Salt River Project, have neglected grid maintenance. APS officials say they have followed the maintenance regimen suggested by manufacturers, and the West's power grid is among the best in the nation.
APS has hired two companies to determine the cause of a July 4 fire at its Westwing Substation and a Tuesday fire at its smaller Deer Valley Substation. APS officials said they believe the fires are unrelated.
"During times like this, there are a lot of people coming out of the woodwork claiming to be experts. We will rely on the manufacturers' recommended maintenance of those units and the third-party experts we have hired to look into the outages," said Alan Bunnell, APS spokesman.
APS and SRP say they have spent billions of dollars building new power plants and improving the transmission system.
The Westwing fire cut out about 20 percent of the Valley's capacity, prompting pleas for conservation to avoid rolling blackouts. The smaller fire at the Deer Valley Substation led utility officials to plan for rolling blackouts in some northwest Valley neighborhoods, but none have occurred. APS is buying six or seven new transformers at $2 million to $3 million each to replace all of the units at the Westwing Substation, Bunnell said.
Arizona is not immune to the effects of industry trends generating predictions of more transformer fires and outages across the nation.
Uncertainty over deregulation in the state prompted utilities to delay power-plant and transmission projects. In 2001, utilities had to bring in portable generators and restart mothballed power plants to keep the Valley's lights burning.
In an Internet article by Patrick McShane, a product manager for Copper Power Systems, which produces transformer fluid, said heavy electrical loads and degrading equipment have created a major risk-management problem in the industry.
He cites insurance-industry data that project a 500 percent increase in transformer failures during the next decade.
Last year, a 500-kilovolt transformer fire at a gateway substation north of Los Angeles, similar to the Valley's Westwing facility, jolted California's power grid but caused momentary outages. But the damaged substation is still being repaired, and, as with the Valley, its loss has compromised the supply of electricity entering the Los Angeles Basin.
In April, a 230-kilovolt transformer blew up in northern California, and in 2002 another 230-kilovolt transformer caught fire in Boulder City, Nev.
Like the Arizona fires, the California and Nevada blazes were generally attributed to internal electrical failures that ignited thousands of gallons of mineral oil used to keep the units cool.
Paulette Stewart, a spokeswoman for S.D. Myers Inc., a Tallmadge, Ohio, company that maintains and refurbishes power substations and transformers, said such fires can be caused by lightning, power surges, faulty paper insulation, flaws in the copper coils and other factors.
The two transformer arrays that ignited at Westwing and Deer Valley were made by Westinghouse, and each is about 30 years old, APS said. Stewart said it is not uncommon for a transformer to last 50 to 60 years if properly maintained.
http://www.azcentral.com/news/articles/0722power-maintain22.html