NOTICE DATE: March 4, 2025

NOTICE TYPE: M-A030425-01 Operations

SHORT DESCRIPTION: Implementation Details of NPRR1145, Use of State Estimator-Calculated ERCOT-Wide TLFs in Lieu of Seasonal Base Case ERCOT-Wide TLFs for Settlement

INTENDED AUDIENCE: All Market Participants, Qualified Scheduling Entities (QSEs), Load Serving Entities (LSEs)

DAYS AFFECTED: March 28, 2025

LONG DESCRIPTION:  On March 28, 2025, Protocol language associated with Nodal Protocol Revision Request (NPRR) 1145, Use of State Estimator Calculated ERCOT-Wide TLFs in Lieu of Seasonal Base Case ERCOT-Wide TLFs for Settlement, will be implemented.

NPRR 1145 changes the 15-minute level ERCOT-wide Transmission Loss Factors (TLFs) that are used in the Settlement process from seasonal base case TLFs to State Estimator-calculated TLFs in the Energy Management System (EMS). It also clarifies the use of Non-Opt-In Entity (NOIE) deemed actual TLFs to remove behind-the-meter Transmission Losses.

ACTION REQUIRED: Impacted Market Participants should implement changes to their shadow Settlement systems to incorporate the Protocol revisions made by NPRR 1145.

ADDITIONAL INFORMATION: Pursuant to Protocol Section 21.6, Nodal Protocol Revision Implementation, ERCOT is required to provide notice as soon as practicable, but no later than ten days prior to implementation.  

NPRR 1145 and the associated documents can be found on the ERCOT website.

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