NERC is seeking comments from industry stakeholders through Nov. 25 on a proposal to expand the categories of information collected in the Transmission Availability Data System (TADS) to improve the ERO’s understanding of load loss.  

The comment request was filed under Section 1600 of NERC’s Rules of Procedure, which grants the ERO the power to request data from registered entities “that is necessary to meet its obligations under Section 215 of the Federal Power Act.” Section 1600 data requests must be reviewed by FERC, posted for public comment, and reviewed by NERC’s Board of Trustees before they take effect. 

FERC reviewed the request in September, according to background information provided on NERC’s website. After the public comment period concludes in November, NERC staff will respond to comments and complete any necessary revisions before submitting the final proposal to NERC’s board at its open meeting in February. The ERO hopes to implement the changes to TADS by Jan. 1, 2026. 

Under the proposal, three items would be added to TADS reporting: 

• • load-loss data resulting from transmission system outages. 

• • geographical data for TADS elements. 

• • equipment sub-cause codes to supplement existing cause codes. 

NERC said it uses load-loss data “voluntarily collected by the IEEE Distribution Reliability Working Group for its analysis.” However, the organization is concerned about the completeness of this voluntarily provided data and its ability to fully represent an interconnection. In addition, the presence of a third party in the data-collection chain complicates the process of tying load-loss information to events. 

The changes should allow the ERO to incorporate more complete load-loss information in the annual State of Reliability (SOR) report and identify transmission system elements involved in specific events through the addition of geographical data, NERC said. Equipment sub-cause codes also will give the ERO better information about the failure rates of specific equipment types, recommend more specific measures to prevent outages and identify trends for the SOR and other studies.  

The data request will apply to all registered transmission owners (TO) that own either overhead or underground AC and DC circuits, transformers with a secondary voltage of at least 100 kV and AC/DC back-to-back converters. As with existing TADS data requests, information will be due 45 days after the end of each calendar quarter.  

In their comments, NERC is asking applicable TOs to respond to the following: 

• • whether they collect data on load loss, geographical location and equipment sub-cause codes for operation of their transmission systems. 

• • whether the data requested is reasonable and obtainable. 

• • whether the implementation schedule for the request is reasonable. 

NERC emphasized that answers to these questions are not required but “would be appreciated.” Respondents also are free to provide any other comments they would like regarding the data request. Stakeholders must email their responses to NERC, using the comment matrix form on the Section 1600 website.