June 14, 2004
By Jennifer Sterba
© 2004 Arizona Daily Star

Power was shut off to 35,000 Tucson customers for less than an hour this morning after a unit at the Palo Verde Generating Station west of Phoenix stopped working.
Customers scattered randomly across Tucson lost power about 7:40 a.m.

Power was turned on again for the last customer around 8:35 a.m.

The power irregularity caused Tucson Electric Power's sytem to lose 60 megawatts, affecting random areas throughout Tucson, said Joe Salkowski, a TEP spokesman.

TEP is connected to Palo Verde via a regional electrical grid.

"Power is generated as needed. It can't be stored," he said. "At any given moment, there is an equal amount of power being generated and used."

So when one of Palo Verde's three units stopped generating power, TEP couldn't deliver electricity to a portion of Tucson.

"There was nothing wrong with our system," Salkowski said. "What happened was automatic. Our system is set up to do exactly what it did."

Spokespersons with Arizona Public Service, which owns a 29.1 percent share of Palo Verde, could not be reached for comment on what caused the unit to shot down.

Palo Verde is a pressurized water nuclear reactor with a 3,810 megawatt capacity.
The first unit was completed in 1986, the third in 1988.

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