NOTICE DATE: October 7, 2025

NOTICE TYPE: M-B100725-01 Operations

SHORT DESCRIPTION: Reliability Standard 2025-2026 Magnitude: Request for Information to Transmission Operators and Load Forecast Posting

INTENDED AUDIENCE: Transmission Operators

DAYS AFFECTED: October 24, 2025

LONG DESCRIPTION: On October 7, 2025, ERCOT issued a Request for Information (RFI) to each Transmission Operator (TO) in the ERCOT Region requesting information to determine the magnitude criterion of the reliability standard established by the Public Utility Commission of Texas (PUCT) in 16 Texas Administrative Code (TAC) Section 25.508.  The RFI specific to each TO is posted to the Market Information System (MIS).  The generic RFI is attached here as a PDF.

Pursuant to 16 TAC Section 25.508(b)(3), ERCOT is required to file with the PUCT by December 1 each year "the maximum number of megawatts of load shed that can be safely rotated during a loss of load event and a summary of the methodology used to calculate this value."  ERCOT will utilize TOs' responses to this RFI to inform its annual magnitude filing with the PUCT.  The values provided by TOs in response to this RFI are solely for development of the updated magnitude value to help measure reliability in the ERCOT Region at a system-wide level and will not be used for compliance purposes.

The RFI provides a forecasted peak load for the ERCOT System of 77,338 MW for winter 2025-2026 as well as each TO's respective share of that load.  A spreadsheet containing the load forecast is attached.  Additional information on the development of this forecast is posted to ERCOT's Load Forecast webpage and will also be described in ERCOT's forthcoming magnitude filing with the PUC.

ACTION REQUIRED: Each TO in the ERCOT Region must send ERCOT its response to the RFI by 5:00 P.M. on October 24, 2025.

CONTACT: If you have any questions, please contact your ERCOT Account Manager. You may also call the general ERCOT Client Services phone number at (512) 248-3900 or contact ERCOT Client Services via email at ClientServices@ercot.com.

If you are receiving email from a public ERCOT distribution list that you no longer wish to receive, please follow this link in order to unsubscribe from this list: http://lists.ercot.com.

dg