Grid Reliability & Security

Reliability Results

We strive to minimize the frequency and duration of service interruptions. As part of a long-term reliability strategy, we perform critical analyses of our transmission and distribution systems to identify areas requiring proactive maintenance. We track our response to interruptions using four reliability performance indicators. Below are our 2017, 2018, and 2019 storm-normalized reliability results as recorded by our interruption monitoring system.

Reliability Results

The number of interruptions lasting more than five minutes that an average customer experienced during the year.

  2017 2018 2019
Goal  <1.3 <1.3  <1.3
Actual  1.4 1.31  1.45


The average length of time a customer was without service during a sustained interruption.

  2017 2018 2019
Goal  <62 minutes <62 minutes <62 minutes
Actual  61.45 minutes 64.93 minutes  88.73 minutes


The average minutes of sustained interruption per customer during a year.

  2017 2018 2019
Goal  <80 minutes <80 minutes  <80 minutes
Actual  86.5 minutes 85.29 minutes  128.24 minutes


The number of interruptions lasting five minutes or less that an average customer experienced during the year.

  2017 2018 2019
Goal  <6.5 <6.5  <6.5
Actual 6.24  6.15  5.53


We participate in the Edison Electrical Institute (EEI) benchmark survey to measure our results along with those of other utilities. Our MAIFI and SAIFI results are often higher due to our large and vast service territory, while SAIDI and CAIDI results tend to be lower. In 2019 our results were impacted by the implementation of our new interruption monitoring system. The system captures additional interruptions, which accounts for a rise in our SAIDI result compared with 2018. The new system's lack of historical data also impacted the calculations of Major Event Days for exclusion in 2019 results.

Aware that the new system would affect our results, we set 2019 reliability goals by using existing data to make the most accurate predictions possible. Our plans for improving reliability include integrating geographic information system data, strengthening the electrical system, and developing continuous improvement workshops to improve efficiencies and processes. 


Compromises to cybersecurity pose a serious threat to the privacy of customer data and to the reliable operation of the electric system. To mitigate risk, we continue to secure systems and software and to educate and train employees on security and awareness. We’re regulated by the Federal Energy Regulatory Commission to comply with the Critical Infrastructure Protection Cybersecurity Standards. To comply with these standards, we leverage processes, controls, and technology to maintain physical, electronic, and protected information security for sites identified as impacted facilities.

The standards require us to categorize our cyber assets as high, medium, and low impact. We support our high- and medium-impact cyber assets to meet the required standards. These cyber assets must be programmable and located at certain control centers and generation and transmission facilities identified in the standards. We support our low-impact cyber assets for incident response/cybersecurity awareness to meet the required standards. We had no cybersecurity issues in 2019. We met the January 1, 2020, standard requirement for physical security. 

Preparedness Planning

Our company has history of actively engaging in the reliability of the system. Pursuant to the United States Federal Power Act, the Federal Energy Regulatory Commission (FERC) established the North American Electric Reliability Corporation (NERC) as the Electric Reliability Organization (ERO). NERC is the designated entity responsible for ensuring the effective and efficient reduction of risks to the reliability and security of the grid. As a NERC registered entity, we are actively engaged in the reliable operations of the system. Our company is a Local Balancing Area within the Midcontinent Independent System Operator, Inc. (MISO).

As evidenced via NERC public records, we have an outstanding record of compliance with the NERC Reliability Standards.

Presently, the we have an executive level officer on the Midwest Reliability Organization (MRO) Board of Directors, the NERC Reliability Issues Steering Committee, which is the highest level executive committee reporting to the NERC Board of Trustees, and the MRO Reliability Advisory Council. We are also a member of the North American Transmission Forum.

We have participated in the NERC GridEx events since their inception in 2011, and have been a leader and participant in numerous other emergency preparedness exercises at the state and local levels. Our involvement is integrally tied to managing and mitigating risk to ensure our company is prepared to provide reliable operations.

Our company incorporates recommendations and compliance obligations into our preparedness plans. We have approximately 20 situation-specific documents that provide a systematic approach to managing crises without causing major disruption to normal activities. These documents are general guidelines we supplement with employee education and training. We did not have any incidents in 2019 causing us to activate our preparedness plans.