Entergy’s reliability has improved significantly since 1998 as a result of the company’s efforts. The company introduced a new outage reporting system in 1998 that greatly increased the accuracy of reported outages. In addition, Entergy significantly increased reliability spending beginning in 1999. The improved reliability is especially significant when considering the number and degree of adverse conditions that affect Entergy’s service territory. Back-to-back historic challenges occurred in 2005 and 2008 when Entergy was affected by four of the most destructive hurricanes ever to hit the United States.
SAIFI and SAIDI:
Electric utilities primarily use two industry-wide reliability indices. The System Average Interruption Frequency Index captures the frequency or number of interruptions experienced by a typical customer. The System Average Interruption Duration Index captures the duration or total number of minutes of interruptions experienced by a typical customer.
Entergy’s reliability improvement gains have proven more difficult to attain with each year that passes. The easy fixes have been corrected. What remains are the more difficult reliability problems. Entergy must continue to:
- manage the reliability improvement effectiveness of all the improvement efforts.
- fund the existing basic reliability improvement programs.
- find ways to provide additional opportunities for reliability improvement.
- implement reliability technology.
Entergy Programs to Improve Reliability:
Entergy’s System 2011 SAIFI score improved 54 percent since 1998. The system 2011 SAIDI improved 25 percent in the same timeframe. Small up and down variations from year to year are due to weather. Overall improvement trends can be attributed to several actions Entergy has taken in recent years:
- Continued emphasis on the Targeted Actions Centered Toward Improving Customer Satisfaction program. TACTICS seeks to uncover the root cause of distribution devices experiencing repeated outages. The program finds repeatedly offending devices and corrects the root causes of failure.
- Utilization of the Targeted Circuit program, which concentrates annual improvement work on the worst performing feeders across Entergy’s system. A small number of poor-performing feeders can significantly affect a reliability index. This program strives to concentrate work on the feeders providing the greatest opportunity for improvement.
- Establishment of infrastructure / maintenance programs to focus on maintaining a properly functioning electric distribution system. These programs, which satisfy the requirements of the National Electric Safety Code, consist of regular inspections and appropriate replacements of key equipment, such as poles, capacitors, regulators, reclosers, underground cables, etc.
- Creation of the backbone feeder inspection program, which provides for inspection of the main circuit backbone on a cycle bases. This initiative promotes a low cost “patrol and fix-what-is-broken” effort which eliminates the need to wait for a feeder’s performance to degrade before attending to reliability improvement.
- Improvements to the company’s vegetation management process in order to move away from reactive trimming and establish a system to trim each electrical distribution feeder proactively, based on its own unique trim cycle.
- Entergy is developing new ways to enhance performance through technology.
- Distribution automation can detect an outage, perform intelligent decision-making, and reconfigure the system. This cuts the outage time for many customers to a few minutes, instead of the longer time needed to manually reconfigure the system.
- Fault-monitoring technology can pinpoint a fault’s location. Response personnel can arrive sooner and reduce the outage length.
- Research in hardening assets along the coastal regions to reduce the affects of hurricanes.
Entergy Reliability Compared with Other Utilities:
Like other utilities across the nation, Entergy’s reliability is adversely affected by vegetation, lightning and animal contacts. But, Entergy's percentage of outages from these causes is significantly more than for other utilities. This is due in part to Entergy’s service territory being located in the South and Southeast. In addition, Entergy:
- Serves many rural areas where population is sparse, requiring longer lines.
- Contains several of the most vigorous vegetation growth zones in the continental United States.
- Is subjected to some of the most intense lightning activity in the continental United States, exceeded in intensity only by the Florida peninsula.
- Experiences some of the highest rainfall amounts in the nation.
- Has one of longest vegetation growing seasons in the nation.
- Has significant exposure to Gulf Coast hurricane activity.
Despite these adverse conditions affecting reliability, Entergy has made steady progress in recent years. The company will continue to strive to improve its reliability record.