AEP Sustainability - Reliability Performance

Reliability Performance

The electric power grid is essential to the economic vitality and well-being of society. It is our top-priority to provide customers with a safe, reliable, secure and resilient power grid to meet their energy needs at all times. We are dedicated to meeting this standard and continuously improving upon it.

Despite our excellent service record and our continuous efforts to improve reliability, there are times when our performance does not meet our customers’ needs or expectations. Equipment failure from aging grid components, falling trees and tree limbs, and damage from severe weather cause outages that, depending on the severity, can have negative impacts on our customers.

We rely on three key metrics to measure the reliability of our system.

  • The System Average Interruption Duration Index (SAIDI) represents how many minutes the average customer experiences an interruption in electric service in a given year. During 2018, the AEP System SAIDI was 256.6 minutes, excluding major events, a 19% percent increase from 2017. The growth of vegetation contributed to about 38 percent of SAIDI results, and equipment failure accounted for about 22 percent of SAIDI.
  • The System Average Interruption Frequency Index (SAIFI) represents the number of interruptions experienced by customers in a year. During 2018, the system’s SAIFI was 1.531, a 10 percent increase from 2017. Vegetation and Distribution Line equipment failures were also the major contributors to SAIFI performance.
  • The Customer Average Interruption Duration Index (CAIDI) represents the average length of time it takes to restore service when an outage occurs. AEP’s 2018 CAIDI was 167.7 minutes, an 8 percent degradation from 2017.

The deterioration of performance in 2018 was due to a combination of many factors, most notably a higher frequency of storms, an increasing number of vehicle accidents that damaged equipment and trees outside of rights-of-way (ROW) falling into our equipment.

When an outage occurs, the first thing a customer wants to know is when the power will be restored to their home or business. One of AEP’s primary concerns during these events is to quickly establish and share with customers a global estimated time of restoration (ETR). Providing an accurate ETR – and restoring power within that timeframe – is crucial to maintaining high customer satisfaction. Because it is such an effective and important tool for keeping our customers informed, we are continually looking for new ways to share and improve the accuracy of the ETR.

AEP provides customers with an array of tools to make it easy to report service interruptions and track their ETR. Customers who sign up to receive service alerts can receive timely information about their ETR by text message or email. More than 2 million customers have already enrolled in AEP’s mobile alerts. In addition, the mobile app is particularly useful during outages as it allows customers to use their smart-phones to instantly report and monitor our restoration progress. Read more about this in the customer experience section of this report.

AEP also provides public access to mobile-friendly, online interactive maps that provide detailed information about power outages. These maps are easily accessible on the AEP website and mobile app and provide all interested stakeholders with greater transparency regarding outages. Users can search for details and updates by street, city, ZIP code or county to track AEP’s restoration progress, without the need to log into a customer account.

Public Service Company of Oklahoma’s Distribution Automation Circuit Reconfiguration Program allows circuits to “self-heal” to the extent that is practical in the event of a power outage. This technology is currently on 45 circuits including locations where customers have expressed a need for continuous power.

We are currently working on the development of a storm prediction model in partnership with major universities. In addition to enhancing our ability to predict and prepare ourselves when severe weather is imminent, the prediction tool will also alert our customers to help them prepare for potential power outages that could impact them as a result of severe weather. This is an example of enhancing the customer experience by providing value-added information they can use.

Momentary Average Interruption Frequency Index

We expect momentary outages will become a more significant concern for our customers as consumers use more electronics. The Oklahoma Corporation Commission now requires electric utilities to start reporting a Momentary Average Interruption Frequency Index (MAIFI) to the extent possible. Due to the nature of this metric, gathering the data necessary to track and report MAIFI was not possible before we implemented smart metering.

In 2018, PSO partnered with GridCure, a third party data company, to develop a “blink module.” The technology uses Advanced Metering Infrastructure (AMI) data to target potential power quality issues on the distribution system before they become a problem for customers. This will allow us to pinpoint areas where problems occur and take proactive corrective action. The technology will be released in 2019.