TVA delivers power 99.999% of the time

CLEVELAND, Tenn. -- Standing beneath the towering lines and switches at one of TVA's newest substations, Jeff Miller scans the overhead electrical equipment with his thermal-imaging camera, looking for any hot spots that might indicate a problem.

Using another electronic hand-held device, Mr. Miller conducts a diagnostic assessment of nearby transformers. After shipping the data via telephone to TVA's power headquarters in Chattanooga, the mobile device spits out a report indicating whether there are any oil or gas leaks.

"Oil in a transformer is kind of like our blood," said Tracy Flippo, TVA's vice president of transmission operations and maintenance. By keeping an eye on the "blood," TVA workers can see if there are developing issues with the transformers "and we can take it out of service before a problem develops," he said

As a maintenance electrician, Mr. Miller is among more than 500 transmission department employees at TVA who work most of the time trying to avoid problems before they occur.

Aided with new detection technologies and faster fiber-optic communication and switching equipment, TVA has managed to deliver its power 99.999 percent of the time for each of the past 10 years.

Last year, TVA's power outages averaged only 7.8 minutes for the entire year across all customers in its entire seven-state region. That placed TVA among the top 10 percent of utilities for reliability in the nation.

"I don't know many businesses that can claim that kind of quality," TVA President Tom Kilgore recently told the Rotary Club of Chattanooga. "Even Ivory Snow was only 99 and 44/100ths pure."

Officials say the performance record can be attributed, in part, to TVA's $1.1 billion investment in its transmission system since 2000, including the opening in June 2008 of the $60 million substation in rural Bradley County.

"We developed a plan to replace equipment, from poles and wires to entire stations, and followed that with a strategy to maintain the system that continues today," said Bob Dalrymple, vice president of transmission and reliability at TVA.

The utility no longer waits for problems to develop along its 16,000 miles of transmission lines, using helicopters to visually inspect all of its major transmission lines every three years and a host of self-testing equipment to spot potential equipment problems.

Even with better technology, the agency must battle everything from lightning strikes to buzzard feces.

"It only takes one bolt of lightning to affect the system," Mr. Flippo said.

When problems do develop, TVA dispatches maintenance crews from 18 field offices spread across the Tennessee Valley.

"We have to respond to emergencies at all times of the day and night, often in the worst kinds of weather," Mr. Flippo said. "We'll never be perfect, but we work to get better all the time with our personnel, our training, our processes and our equipment."