Reliability
Significant
Improvement:
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.
The Challenge:
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.
• recover from the hurricanes Katrina, Rita, Gustav and Ike, the four most
destructive hurricanes ever to hit the Entergy service territory.
Entergy Programs to Improve Reliability:
Entergy’s System 2009 SAIFI score improved 51 percent since 1998. The system
2009 SAIDI improved 24 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 basis. 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 and repair problems.
• Fault-monitoring technology can pinpoint a fault’s location. Response
personnel can arrive sooner and reduce the outage length.
• Entergy is developing and enhancing methods for 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 performance enhancement. The company will continue to
strive to improve its reliability record.
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