Texas RE's Reliability Services group provides Regional coordination and execution of reliability assessments, performance analysis, events analysis, situation awareness, and infrastructure security; we also conduct internal review of system performance, outlook and risks to the bulk power system (BPS). These programs aim to better characterize present or emerging risks and to develop insights into potential impacts and mitigation strategies. A key function of Reliability Services is to facilitate the exchange of information and dialogue among stakeholders to promote a culture of reliability excellence.

The Event Analysis program promotes a structured, non-criticizing approach that identifies root and contributing causes, along with lessons learned across the industry. Texas RE strives to develop a culture of reliability excellence that promotes aggressive self-critical review of operations, planning, and critical infrastructure protection (CIP) processes. The event analysis process also serves as a learning opportunity for industry by identifying and disseminating valuable information to enable improved and more reliable operation.

An event is defined as “an unwanted, undesirable change in the state of plants, systems, or components that leads to undesirable consequences to the safe and reliable operation of the system.” Events can be avoided proactively or reactively. Combining proactive and reactive methods is the best strategic approach for identifying and eliminating hidden organizational weaknesses and situations that can cause an event to occur. NERC’s Event Analysis Program aims to promote the reliability of the BPS in North America. This goal is directly supported through Texas RE and stakeholders' cooperative efforts in:

  • Evaluating BPS events.
  • Understanding the underlying cause of events.
  • Undertaking appropriate levels of analysis to determine the causes of events.
  • Promptly implementing corrective actions.
  • Providing recommendations and lessons learned to the industry.
  • Providing valuable feedback to the reliability standards development process, compliance enforcement, training and education, and reliability trend analysis efforts.
  • Developing a culture of reliability excellence that promotes and rewards aggressive self-critical review and analysis of operations, planning, and critical infrastructure protection processes.

Successful event analysis relies on a collaborative approach through which registered entities, Regional Entities (REs), and NERC work together to first understand causal factors and then to determine appropriate mitigation and implement it.

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Event Contact Information

NERC Reliability Standard EOP-004-3 requires submittal of disturbance reports to NERC, Texas RE, and the Department of Energy (DOE) to monitor major system incidents on electric power systems. ERCOT Operating Guide Sections 3.2.3 and 3.8 require submittal to ERCOT ISO as well. Consult the Reliability Standard for details on reporting thresholds, timelines, and forms. Initial reports are due within 24 hours of recognition of meeting an event threshold, with follow-up required within 72 hours in some instances for OE-417 reports to the DOE.

For NERC Event Reports and OE-417s, please use these email addresses:

Online submittal is available for OE-417 reports to the DOE, but copies must be emailed to ERCOT, Texas RE, and NERC at the email addresses above. NERC and Texas RE will accept the DOE OE-417 form in lieu of the NERC EOP-004-2 Event Reporting Form if the entity is also required to submit an OE-417 report.

Event Analysis Reports

As a learning tool, Texas RE event analysis serves an integral function of providing insight and guidance by identifying and disseminating valuable information to owners, operators, and users of the BPS to enable improved and more reliable operation.

Texas RE has posted public versions of event analysis reports from events that occurred in the ERCOT region below.


Situational Awareness monitors ongoing system conditions and coordinates with NERC and governmental agencies to share information (respecting confidentiality) on developing situations such as storms, natural disasters, human threats, and geopolitical events that may potentially impact the BPS. Texas RE promotes stakeholder participation in programs sponsored by industry and government, including NERC Alerts, the Electricity-Information Sharing and Analysis Center (E-ISAC), GridEx, and several NERC conferences: GridSecCon, the Human Performance Conference, and the Monitoring and Situational Awareness Conference. In addition, Texas RE hosts local events such as the generator winter preparation workshops and provides outreach in other forums. These aim to help the industry understand and prepare for natural and human-based threats to the BPS. For more information about each of these, please see below, or contact Texas RE RAPA.

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NERC Alerts

NERC discovers, identifies, and provides information that is critical to ensuring the reliability of the BPS in North America. NERC disseminates this information through e-mail alerts, which are divided into three levels:

  1. Industry Advisory – Purely informational, intended to alert registered entities to issues or potential problems. A response to NERC is not necessary.
  2. Recommendation to Industry – Recommend specific action be taken by registered entities. Require a response from recipients as defined in the alert.
  3. Essential Action – Identify actions deemed to be essential to BPS reliability. Require NERC Board of Trustees approval prior to issuance. Like recommendations, essential actions also require recipients to respond as defined in the alert.

Texas RE forwards NERC Alerts as necessary and as permitted by handling requirements of the alert, assisting registered entities in using the system, and providing outreach.

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Electricity – Information Sharing and Analysis Center (E-ISAC)

The E-ISAC serves the electricity sector by facilitating communications between electricity sector entities, U.S. and Canadian federal governments, and other critical infrastructure sectors, in order to improve the ability to prepare for and respond to cyber and physical threats, vulnerabilities, and incidents. The E-ISAC promptly disseminates threat indications, analyses and warnings to assist electricity sector entities to evaluate the situation and take appropriate actions.

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Generator Winter Preparation

Texas RE and ERCOT ISO review winterization plans at generating stations from December to February of each winter season (reference ERCOT Nodal Protocol 3.21 and Public Utility Commission of Texas Substantive Rule 25.362 (i)(2)), including on-site visits that consider design criteria, critical instrumentation, freeze protection systems, fuel supply (including alternate fuels), transformer oil levels, winter emergency stores items, training, operational inspections, and other topics. Annual winter preparation workshops typically held in September highlight regional generators’ efforts to improve preparations for extreme cold weather and support better communications during frigid conditions. Texas RE contributes to and promotes NERC-issued guidance, lessons learned, and training material based on winter experiences of Generator Owners.

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NERC conducts a biennial grid security and emergency response exercise, GridEx. The objectives of GridEx are to:

  • Exercise crisis response and recovery;
  • Improve communication;
  • Identify lessons learned; and
  • Engage senior leadership.

GridEx III provided an opportunity for industry and other stakeholders to respond to simulated cyber and physical attacks affecting the reliable operation of the grid. Led by the E-ISAC, GridEx III was the largest geographically distributed grid security exercise to date. GridEx III consisted of a two-day distributed play exercise and a separate executive tabletop on the second day. More than 4,400 individuals from 364 organizations across North America participated in GridEx III, including industry, law enforcement, and government agencies. Planning for GridEx IV is underway.

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Performance Analysis reviews current and historical reliability trends and metrics to objectively analyze reliability performance, risks, and emerging issues. The ERO-wide analysis is published in the annual NERC State of Reliability report. Texas RE publishes an annual Assessment of Reliability Performance report for the ERCOT region to specifically provide analysis and feedback on risks and reliability trends within the region. Texas RE also coordinates the collection of regional stakeholder data used in these analyses, primarily through NERC’s reliability data systems, as described below.

Performance Analysis Reports

NERC State of Reliability Report

The NERC State of Reliability report represents NERC’s independent view of ongoing BPS reliability trends to impartially analyze the state of reliability based on metric information and provides an integrated view of reliability performance. The key findings and recommendations serve as technical input to NERC’s Reliability Standards and project prioritization, compliance process improvement, event analysis, reliability assessment, and critical infrastructure protection.

ERCOT Region Assessment of Reliability Performance

The goals of the Assessment of Reliability Performance are to illuminate the historical and overall BPS reliability picture, help identify risk areas, prioritize and create actionable results for reliability improvements, and build on successes. This report represents the ongoing effort by Texas RE to provide a view of risks to reliability based on historic performance, integrate many ongoing efforts underway, provide analysis and feedback on risks and reliability trends, and understand the risks impacting reliability performance.


Reliability Data Systems

Texas RE provides coordination, analysis, user training, and support for the collection of performance data key to preparation of reports and other analysis. Applicable registered entities submit outage and availability data through a common NERC web portal managed by Open Access Technology International (OATI). NERC recently developed a separate portal for protection system misoperations.

DADS – Demand Response Availability Data System

Demand Response helps ensure resource adequacy while providing operators with additional flexibility in maintaining operating reliability. The DADS goal is to collect Demand Response data from events and to measure the actual performance to include system reliability. This analysis can provide the industry with a basis for projecting contributions of dispatchable and non-dispatchable Demand Response supporting forecast adequacy and operational reliability. DADS data is input twice yearly by ERCOT and certain registered Distribution Providers (DP) with demand response programs using the OATI webPortal.

DADS ContactBob Collins

TADS – Transmission Availability Data System

TADS collects simple transmission equipment availability data as well as detailed information about individual outage events in a common format. This provides a uniform approach to report and measure transmission availability, performance, and other related transmission system reliability data. Analysis on TADS data at the regional and NERC level will provide information that may be used to improve Bulk Electric System (BES) reliability. Registered Transmission Owners (TO) submit data quarterly through the OATI webPortal for their 138kV and 345kV facilities.

TADS ContactBob Collins

GADS – Generation Availability Data System

GADS collects design, event, and performance data about generation units for improving the performance of hydro and conventional electric generating equipment. GADS data also helps those researching the vast amounts of information on power plant availability. The information is used to support equipment reliability and availability analysis and decision making by GADS data users. Registered Generator Owners (GO) submit GADS data quarterly through the OATI webPortal.

Wind has become a major player in energy. NERC-registered Generator Operators who operate wind plants of 75 MW or greater of total installed capacity, and with a commission date of January 1, 2005 or later, report using the GADS Wind Data Submission Site. Reporting is phased in over a four-year period based on plant MW output. GADS Wind Turbine Generation Data Reporting Instructions assists wind plant personnel in reporting information to NERC. The instructions detail the procedure, schedule, and format to follow when reporting data.

GADS ContactJagan Mandavilli

MIDAS – Misoperation Information Data Analysis System

MIDAS collects protection system misoperation data as well as protection system operation counts in a common format. This provides a uniform approach to report, measure, and analyze protection system performance and to analyze misoperation data. Analysis of MIDAS data at the regional and NERC level provides information that may be used to improve BES reliability. Protection system operations data is submitted through the MIDAS system by GOs, TOs, and certain DPs with 100kV or higher voltage Transmission elements, and is due 45 days after the end of each quarter.

MIDAS ContactDavid Penney

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Texas RE participates in development of NERC Reliability Assessments - specifically the Long-Term Reliability Assessment, Probabilistic Assessment, Short-Term Reliability Assessment, and Short-Term Special Assessment - in coordination with NERC, ERCOT ISO, and stakeholders, primarily through the NERC Reliability Assessments Subcommittee (RAS). The assessment development process includes peer reviews by other Regional Entities prior to finalization of each assessment area’s data and narrative contributions to the final report. These ERO efforts build on ERCOT ISO’s internal Seasonal Assessment of Resource Adequacy (SARA) and Capacity, Demand and Reserve (CDR) reports. Texas RE also supports and provides outreach on special assessments conducted across NERC to assess emerging risks and their potential impacts to reliability on topics such as environmental regulations, growth of renewable generation, changes in resource mix, and interdependency between natural gas and electric power.

Interconnection Model Building Review

NERC has initiated fidelity and quality reviews of the Interconnection power system models used in the study cases that underlie system assessments. As NERC’s designee defined in Reliability Standard MOD-032-1, R4, Texas RE will support the annual creation of the interconnection-wide powerflow and dynamics cases with ERCOT and other registered entities in the Texas Interconnection.