PECO, Philadelphia, Pennsylvania, said it kept the lights on more reliably for its customers in 2007, and the average outage was much shorter than the previous year. PECO said the company responded to 23 percent fewer outage events last year, and the number of customers affected by outages declined by 25 percent.

The company attributed the stronger reliability performance to improved system maintenance, increased spending for capital upgrades to its electric substations and distribution system, more funding for tree trimming around aerial power lines, and fewer damaging storms during the past year.

PECO said the average duration of sustained outages for those affected was 106 minutes, or less than two hours, compared with an average of 135 minutes, or about two hours, during 2006. The average frequency of outages per customer was 0.98, meaning the typical customer experienced only one service interruption in 2007. This measure dropped from 1.33 in 2006, when frequent storms contributed to 46 percent of all of the year’s customer service interruptions.

In summary:

• Outage events dropped 23%,
• Storm related outages was down 60%
• Tree-related interruptions declined 31%,
• Outages caused by equipment failure fell by 9%,
• Customers affected by electric service interruptions were lower by 25%, and the
• Average duration of outages 22 percent was lower than 2006.

“Safe, reliable and responsive service to customers is our goal, and we are very pleased with reliability performance in 2007 that turned out to be one of our best years. We hope our customers noticed a more positive experience,” said Craig Adams, PECO senior vice president and chief operating officer. “We also realize we must do better for some customers, and we’re committed to keep working on improving quality of service for these local areas.”

PECO said its engineers and system operators track reliability in a number of ways in an effort to rate service quality and identify areas for improvement. Events are evaluated based on the circuit or location, cause, duration, and individual customer experience.

A common cause of electric service interruptions is fallen trees or tree limbs contacting power lines or trees growing into overhead lines, especially during storms (about 30 percent of total). Other than trees, outages mainly result from lightning, wind, animal contact, other accidental contacts with power lines, vehicle accidents, and equipment failures. In 2007, 18 percent of outage events were associated with storms in contrast to 36 percent of outages that were considered storm-related in 2006.

With nearly $34 million in annual funding, PECO’s line clearance tree trimming along with the more favorable weather reduced tree-related outage events by 31 percent. More than 283,000 customers did not experience tree-related outages in 2007 compared with the previous year. Improved system maintenance and operations saved nearly 30,000 customers from service interruptions during 2007 due to fewer equipment failures or other operational issues. PECO crews completed more than 15,000 tasks as part of its maintenance program last year. Overall, PECO allocated nearly $300 million in capital improvements for system upgrades, reinforcement and expansion to its electric transmission and distribution system in 2007.

Each year, PECO reports its reliability performance to the state Public Utility Commission with an outline of its system maintenance program and planned capital improvements and areas identified for improvement. PECO maintains about 500 electric substations and more than 2,300 distribution circuits, spanning 13,000 miles, that deliver power to residential, business and institutional customers. On an ongoing basis, PECO prioritizes poor performing circuits for engineering analysis and targeted actions for reliability improvements to benefit customers. Those plans are now being finalized for 2008.