NOTICE DATE: May 15, 2025
NOTICE TYPE: M-A051525-01 Operations
SHORT DESCRIPTION: Potential Price Correction - Generic Transmission Constraint incorrectly being considered in SCED
INTENDED AUDIENCE: All Market Participants
DAYS AFFECTED: March 29, 2025
LONG DESCRIPTION: On March 27, 2025, during a routine software release update for the Energy Management System (EMS), a configuration parameter was inadvertently reset to its default value resulting in a more restrictive limitation. As a result, a post-contingency overload on the Generic Transmission Constraint (GTC) was activated such that it impacted the optimization of Security-Constrained Economic Dispatch (SCED). At times the constraint reached its maximum shadow price of $5,251 per megawatt hour (MWh). See Market Notice M-B040225-01.
In order for ERCOT to seek approval of a price correction by the ERCOT Board of Directors (ERCOT Board), ERCOT Protocols Section 6.3(7)(b) requires that the absolute value impact to any single Counter-Party in the Real-Time Market (RTM) must meet one of the following two criteria:
- 2% and also greater than $20,000 (Protocol Section 6.3(7)(b)(i)); or
- 20% and also greater than $2,000 (Protocol Section 6.3(7)(b)(ii)).
ERCOT has determined that Operating Day (OD) March 29, 2025 has met the criteria for seeking ERCOT Board approval for a price correction. The number of Counter-Parties meeting one of the two criteria for significance are shown in the table below.
|
Operating Day
|
No. of Counter-Parties meeting Criterion 1
|
No. of Counter-Parties meeting Criterion 2
|
|
3/29/2025
|
12
|
12
|
The table below has the maximum estimated absolute value impact to any individual Counter-Party.
| Operating Day |
Maximum Amount |
Maximum Percentage
for Criterion 1
|
Maximum Percentage
for Criterion 2
|
| 3/29/2025 |
$99,580.31 |
49.37% |
98.30% |
ERCOT intends to seek an approval of correction to RTM prices for the impacted OD that met the necessary criteria at the ERCOT Board meeting on June 24, 2025. ERCOT also intends to provide information regarding the price correction to the Technical Advisory Committee (TAC) at its May 28, 2025 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 ClientServices@ercot.com.
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