NOTICE DATE: December 10, 2021

NOTICE TYPE: W-C102921-02 Operations

SHORT DESCRIPTION: ERCOT Board approval of Day-Ahead Market (DAM) price corrections for Operating Days (ODs) September 30 and October 6-12, 2021

INTENDED AUDIENCE: All Market Participants

DAYS AFFECTED: September 30 and October 6-12, 2021

LONG DESCRIPTION: On October 29, 2021, ERCOT informed Market Participants that DAM prices for ODs September 30 and October 6-12, 2021, were impacted by a data input error related to the modeling of the North Edinburg to Lobo (NE_LOBO) Generic Transmission Constraint. ERCOT also notified Market Participants that ERCOT would be seeking ERCOT Board of Directors (Board) review of Day-Ahead Settlement Point Prices (DASPPs), DAM Market Clearing Prices for Capacity (MCPCs), and DAM Locational Marginal Prices (LMPs) for Electrical Buses on those ODs. See Market Notice W-C102921-01.

On December 10, 2021, the Board reviewed DASPPs, DAM MCPCs, and DAM LMPs for September 30 and October 6-12, 2021, and directed ERCOT to implement the appropriate price corrections pursuant to ERCOT Protocol Section 4.5.3(6).

Board approval of these price corrections necessitates the issuance of DAM Resettlement Statements, which are expected to begin being issued the week of December 13, 2021. A Market Notice will be posted for each DAM resettlement, in accordance with ERCOT Protocol Section 9.2.6.

ADDITIONAL INFORMATION: The corrected prices will be posted in both CSV and XML formats in the DAM Price Corrections folder located on the Market Prices on

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 [log in to unmask].

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