PECO, Philadelphia, Pennsylvania, customers experienced 205,500 fewer electric interruptions in 2008 compared to the previous year, or a reliability improvement of 16%, marking the company’s best non-storm performance in 15 years. Additionally, the number of outage events (the actual system problem that results in customer interruptions) dropped by 7.5%.

The city of Philadelphia had the best service reliability in PECO’s six-county service area, while service quality in Bucks County improved the most with a 16% overall reduction in customer interruptions

PECO said its average interruption frequency indicator improved from 0.76 to 0.63 last year, meaning the average customer experienced a power outage only about once every 19 months.

“Keeping the lights on for our customers is the foundation of our service, and we are very pleased with our results for reliability in 2008,” said Craig Adams, PECO senior vice president and chief operating officer. “We closely monitor reliability performance and invest heavily each year in maintaining and making improvements in our electric distribution system. We’ll keep working this year to improve in areas where our service is not yet on par with our customer expectations.”

PECO’s reliability programs, funded with nearly $300 million last year, include bi-annual circuit patrols using infrared cameras; line clearance tree trimming; periodic inspections of electric substations, utility poles, and manholes; targeted projects and equipment upgrades for summer and winter readiness, and other preventive maintenance activities.

The statistics above exclude 13 days with notable storm activity, five more storms than the average year. About 44% of all PECO customer interruptions in 2008 occurred during storms. The company tracks average outage duration as a better indicator of its operational performance in storms. This measure showed the average duration of customer interruptions was 90 minutes during non-storm days and 184 minutes, or roughly three hours, during storm days, which was similar to the previous year.

Overall, trees were considered to cause about a third of all outages in 2008 due to in-growth into aerial lines, fallen tree limbs, or uprooted trees. Other outage causes tend to be wind and lightning, vehicle accidents, animal intrusion, and equipment failure.