CRR; Operations

Thu, Aug 27, 2020 03:58 PM

M-A082720-01 Potential Price Corrections - Incorrect RAS Modeling Impacting Day-Ahead Market

NOTICE DATE: August 27, 2020

NOTICE TYPE: M-A082720-01 Operations

SHORT DESCRIPTION: Potential Price Corrections - Incorrect RAS Modeling Impacting Day-Ahead Market

INTENDED AUDIENCE: All Market Participants

DAYS AFFECTED: August 20 - 24, 2020

LONG DESCRIPTION: On August 24, 2020, ERCOT became aware of a data input error related to the modeling of the Stryker Creek Remedial Action Scheme (RAS) in the Day-Ahead Market (DAM). When ERCOT staff executed a manual change in the ERCOT Market Management System (MMS) on August 19, 2020, to enable the Bearkat RAS in the DAM, the Stryker Creek RAS was inadvertently disabled . The Stryker Creek RAS was incorrectly disabled in the DAM for Operating Days (OD) August 20 to 24, 2020. ERCOT re-enabled the Stryker Creek RAS in the DAM effective OD August 25, 2020. This issue did not impact the Real-Time Market.

When ERCOT determines that there are conditions that cause questionable DAM prices, it must notify Market Participants that DAM prices are under investigation. See ERCOT Protocol Section 4.5.3(3). On August 25, 2020, ERCOT provided a Public Notice that prices for DAM OD 08/24/20 were under investigation due to the incorrect disabling of a RAS.  Thereafter, ERCOT issued a Public Notice that ERCOT corrected DAM prices for OD 08/24/20 before prices became final. See ERCOT Protocol Section 4.5.3(4)(a).

ERCOT has completed an initial analysis and determined that the incorrect disabling of the Stryker Creek RAS also impacted DAM prices on ODs 8/20/20, 8/21/20, and 8/23/20. When ERCOT determines that DAM prices are in need of correction after prices are final and intends to seek review of such prices by the ERCOT Board of Directors (Board), ERCOT must notify Market Participants no later than 30 days following the relevant OD. See ERCOT Protocol Section 4.5.3(5)(a).

ERCOT intends to seek ERCOT Board review of DAM prices for ODs 8/20/20, 8/21/20, and 8/23/20, at the October 2020 ERCOT Board meeting.

ADDITIONAL INFORMATION: ERCOT plans to present the impact analyses concerning these potential price corrections at stakeholder meetings as the information becomes available. Supporting documents and re-calculated prices will be included in materials for the ERCOT October 2020 Board meeting.

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

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