Lack of Redundancy

A TEP power-line upgrade would still leave Santa Cruz County residents vulnerable to blackouts

High school graduation is an especially joyous occasion in a small town. In 2005, however, the ceremony in Nogales took a dark turn. Literally.

Power went out during the outdoor evening event, and megaphones had to be used by the various speakers. As a result, the graduates' names couldn't be heard as they crossed the stage to receive their diplomas.

"We're very proud of them," the Nogales International newspaper (which, like the Tucson Weekly, is owned by Wick Communications) quoted school principal Mark Valenzuela as saying about the graduating seniors. "It was kind of frustrating for them, but they hung in there."

All of the residents of Nogales have been hanging in there, suffering for years from periodic extended blackouts due to a lack of electrical redundancy. Only one major transmission line now runs south to Nogales, from near Vail east of Tucson. Carrying 115 kilovolts of power, the line serves much of Santa Cruz County.

Natural-gas-powered turbines in Nogales provide a limited backup, but if the turbines aren't working, Nogales can be left without electricity when the transmission line goes out of service. That's exactly what happened during the graduation ceremony: A storm knocked out the power line, so parts of Santa Cruz County were dark for several hours.

This power-outage problem and lack of electrical redundancy for the border region has been recognized for more than a decade. In 1998, the city of Nogales filed a complaint about power outages with the Arizona Corporation Commission (ACC). In response, the ACC ordered Citizens Utilities Company, which then supplied electricity to Nogales, to install a second transmission line by the end of 2003.

"The bottom line," the local chamber of commerce commented in a 2001 letter, "(is that) Nogales and Santa Cruz County needs new and reliable power sources, and soon."

A 2001 study looked at the Nogales power supply and, according to a story in the International, concluded: "Stabilized delivery of electric power would greatly improve opportunities for new industry and commerce."

But the matter of getting a second power line to Nogales soon became extremely complicated. Citizens in 2003 was acquired by UniSource Energy Services, which then assumed responsibility for meeting the ACC requirement.

By that time, UniSource, the parent company of Tucson Electric Power, had indicated to the ACC that it wanted to run a 345-kilovolt line to the border city. This line would also provide power to the potentially lucrative electrical market of Sonora, Mexico.

The route selected for UniSource's new 150-foot towers ran west of Interstate 19, cutting through the Coronado National Forest. While the ACC supported this idea, the U.S. Forest Service and many area residents did not. (See Tim Vanderpool's accompanying story on Page 15.)

"That project's in limbo," comments Joe Salkowski, a spokesman for UniSource, about the controversial 345-kilovolt proposal. "We're the innocent babies in this situation."

The ACC apparently isn't pressuring UniSource to install a second transmission line to Nogales. Instead, since a 2004 decision which required the company to make some other improvements to the Nogales electrical system, the mandate for implementing the second line has been on hold.

UniSource has now applied to upgrade its existing line to Nogales in order to meet more of the current electrical needs of the community, although the company does not suggest that the upgrade is an alternative to the 345-kilovolt proposal. The 138-kilovolt upgrade would follow basically the same route as the present 115-kilovolt transmission line, but UniSource will replace its existing wooden poles with 70- to 85-foot-high steel monopoles.

"The situation is not one of outages," Salkowski says of the application, "as much as long-term reliability." He says that the existing line can only supply about two-thirds of the peak power load demanded in Nogales, and adds that additional use of the turbines is not economically ideal for electrical customers.

"It will give us more flexibility in terms of system reliability," Salkowski says about the proposed upgrade. He adds that any rate impacts which result from the construction project "are not going to be dramatic."

While Salkowski does not offer specific figures for power outages in Santa Cruz County, Salkowski does provide a general comparison with Tucson.

"Tucson benefits from multiple connections to the (national) power grid," he says, "so it has more redundancy than Santa Cruz County."

In any case, the current application leaves the issue of the ACC-required second transmission line to Nogales unresolved.

"The upgrade was seen as something the company could do more quickly, along with installing new turbines a few years ago," Salkowski explains.

That explanation may not offer much consolation to the 16,000 UniSource customers in Santa Cruz County who lost power for a few hours the night before Thanksgiving last year. One of those most impacted by this loss of power was Flavio Gonzalez, the utility director for the city of Nogales. He remembers the extended outage made his job "kind of interesting."

Indicating that he always tries to provide double-coverage for things he deals with, Gonzalez believes UniSource should do the same.

"This situation has been going on for years," Gonzalez says about electrical outages. "It behooves (UniSource) to invest the money to take care of their responsibilities."