Entergy Arkansas

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.

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.

SAIFI and SAIDI:

Electric utilities primarily use two industry-wide reliability indices. The System Average Interruption Frequency Index (SAIFI) captures the frequency or number of interruptions experienced by a typical customer. The System Average Interruption Duration Index (SAIDI) captures the duration or total number of minutes of interruptions experienced by a typical customer.