Reliability
Significant
Improvement:
Entergy’s reliability has improved significantly in recent years as a result
of the company’s efforts. The improvement has occurred since the company
introduced a new outage reporting system in 1998 that greatly increases 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. A historic challenge occurred in 2005 when
Entergy was affected by two 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, while 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 has passed since 1998. The easy fixes have been corrected,
so what remains to be solved are the more difficult reliability problems.
Entergy must continue to:
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manage the reliability improvement effectiveness of all the improvement
efforts.
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fund the existing basic reliability improvement programs.
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find ways to provide additional opportunities for reliability improvement.
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recover from the hurricanes Katrina and Rita, the two most destructive
hurricanes ever to hit the United States
Entergy Programs to Improve Reliability:
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Entergy’s System 2007 SAIFI score improved 50 percent since 1998. The system
2007 SAIDI improved 34 percent in the same timeframe. Small up and down
varriations from year to year are due to weather. Overall improvement trends
can be attributed to several actions Entergy has taken in recent years:
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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.
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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.
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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.
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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.
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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.
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Entergy is utilizing two new ways to enhance performance through technology
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Distribution automation can detect an outage and perform intelligent
decision-making to 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. Second, fault-monitoring technology can pinpoint a
fault's location. Response personnel can arrive sooner and reduce the outage
length.
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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 nearly 25 percent 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:
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Serves many rural areas where population is sparse, requiring longer lines.
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Contains several of the most vigorous vegetation growth zones in the
continental United States.
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Is subjected to some of the most intense lightning activity in the continental
United States, exceeded in intensity only by the Florida peninsula.
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Experiences some of the highest rainfall amounts in the nation.
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Has one of longest vegetation growing seasons in the nation.
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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. The best method to sustain reliability
improvement is to approach from the long-term perspective, maintaining
reliability programs at a stable level, year after year.
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