Project 2023-01 EOP-004 IBR Event Reporting

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The​ formal comment period for draft one of Reliability Standard EOP-004-5   Event Reporting concluded at 8 p.m. Eastern, Monday, September 11, 2023. The drafting team will review all responses received during the comment period and determine the next steps of the project.

The Standard Authorization Request (SAR) proposes enhancements to EOP-004-4 (EOP-004) focused on ensuring timely reporting by industry to the Electric Reliability Organization (ERO) Enterprise through reporting of events involving inverter-based resources (IBRs). Currently, the standard has relatively large generator loss size thresholds and uses language more suitable for synchronous generation. The SAR proposes to enhance the standard by adding clarity and lowering the generator loss threshold to encompass the lessons from widespread IBR loss events that have occurred. The NERC Inverter-based Resource Performance Subcommittee (IRPS) presented the SAR to the Reliability and Security Technical Committee (RSTC) for comment in September 2022. After responding to the RSTC comments, the IRPS resubmitted the SAR, and the RSTC endorsed the SAR on December 6, 2022. The Standards Committee accepted the SAR on January 25, 2023.  

Standard Affected: EOP-004-4​

Purpose/Industry Need
The proposed project will address the issue that reporting of generation loss events, per the current EOP-004, uses relatively large size thresholds more suitable for synchronous generation; however, NERC and the Regional Entities have analyzed multiple widespread solar PV loss events (some also involving other generation losses as well) across a large number of resources that did not meet the EOP-004 criteria, yet have highlighted systemic reliability risks posed by IBRs that should be reported by applicable entities. This project will modify the existing generation loss criteria so it is more suitable and appropriate for reporting IBR events and so it aligns with past large-scale disturbances analyzed by the ERO. Without these improvements, the ERO must lean on ad hoc reporting per the NERC Event Analysis Process, which is voluntary in nature and involves significantly longer reporting timelines. The EOP-004 standard should be aligned with this process from a reporting size criteria perspective. As reported in numerous ERO disturbance reports, access to data useful for event analysis and risk mitigation following large-scale disturbances has been challenging for IBRs. This has resulted in data unavailability and overwriting by affected facilities since the ERO Enterprise is unable to send requests for information in a timely manner (i.e., must wait for the brief report to be submitted by the associated Reliability Coordinator first). Improved reporting will enable quicker response to widespread IBR loss events and ultimately lead to improved performance of the generation fleet through more detailed analysis and coordination with affected entities, where applicable. 

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Draft Actions Dates Results Consideration of Comments

Draft 1

Cl​ean​ | Redline to Last Approved

Implementation Plan


Supporting Materials

Technical Rationale

Unofficial Com​ment​ Form​​

VRF/VSL Justifications

Initial Ballots and Non-binding Poll

Ballot Open Reminder​



8/30/2023 - 9/11/2023

Ballot Results


 Implementation Plan

 Non-binding Poll 

​Join Ballot Pools​​

7/28/2023 - 8/28/2023

 Comment Period


Submit Comments

7/28/2023 - 9/11/2023

Standard Authorization Request
Clean | Redline​​

Accepted by the Standards Committee​​5/17/23

​ Drafting Team Nominations

Supporting Materials

 Unofficial Nomination Form (Word)​

Nomination Period


Submit Nom​inations

2/7/2023 – 3/8/2023

​Standar​d Authorization Request​​

​Supporting Materials

Unofficial Comment Form (Word)

​Comment Period


Submit Comments

2/7/2023 – 3/8/2023