NOTICE DATE: December 30, 2021
NOTICE TYPE: W-A123021-01 Operations
SHORT DESCRIPTION: Change to maximum Shadow Prices for constraints previously determined as irresolvable by SCED
INTENDED AUDIENCE: ERCOT Market Participants
DAYS AFFECTED: January 1 and 30, 2022
LONG DESCRIPTION: Section 3.6.2 of the Other Binding Document, Methodology for Setting Maximum Shadow Prices for Network and Power Balance Constraints, requires ERCOT to review annually each constraint previously determined irresolvable by Security-Constrained Economic Dispatch (SCED) and determine (1) if the constraint has become SCED resolvable, and, if not, (2) re-determine the maximum Shadow Price for a constraint that continues to be irresolvable by SCED.
Effective January 1, 2022, the following changes in maximum Shadow Price will be made to the set of constraints that are consistently irresolvable by SCED:
| Contingency Name |
Constraint Name |
From Station / kV |
Description |
Current Maximum Shadow Price ($/MWh) |
Maximum Shadow Price Effective 1/1/2021 ($/MWh) |
| BASE CASE |
VALIMP |
N/A |
Valley Import Base Case |
2000 |
2000 |
| SBEVASH8 |
HAMILT_MAVERI1_1 |
HAMILTON/ 138 |
Loss of the ASHERTON to BEVO 138kV line overloads the 138kV line from HAMILTON to MAVERICK |
2000 |
2000 |
| SCRDJON5 |
915__E |
CMBSW/138 |
Loss of the JOHNSON SWITCH (ONCOR) to CONCORD 345kV Single Circuit overloads the 138kV Line from DECORDOVA DAM to CARMICHAEL BEND SWITCH |
2000 |
3500 |
Additionally, effective January 30, 2022, the following constraints will no longer be considered irresolvable by SCED:
| Contingency Name |
Constraint Name |
From Station / kV |
| DNEDWED8 |
AZTECA_HEC1_1 |
HEC / 138 |
| SMV_ALT8 |
479T479_1 |
WESLACO / 138 |
| SPHAWES8 |
KEY_SW_N_MCAL1_1 |
KEY_SW / 138 |
| SHACPB38 |
LYNX_TOMBST1_1 |
LYNX / 138 |
Section 3.6 of the Methodology for Setting Maximum Shadow Prices for Network and Power Balance Constraints document requires a 30-day notice before the Shadow Price caps for SCED resolvable constraints are reset to their default values. Accordingly, the identified constraints above will have their Shadow Price caps reset to their default Shadow Price cap values on January 30, 2022.
ADDITIONAL INFORMATION: The Methodology for Setting Maximum Shadow Prices for Network and Power Balance Constraints document can be found on the Real-Time Market, and Other Binding Documents List pages of the ERCOT website.
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