NOTICE DATE: December 31, 2014 NOTICE TYPE: W-A123114-01 Operations SHORT DESCRIPTION: Change to maximum shadow prices for constraints previously determined as irresolvable by SCED INTENDED AUDIENCE: ERCOT Market Participants DAY AFFECTED: January 1, 2015 and January 30, 2015 LONG DESCRIPTION: ERCOT Business Practice, Setting the Shadow Price Caps and Power Balance Penalties in Security Constrained Economic Dispatch, Section 3.6.2 requires ERCOT to review 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 Shadow Price for a constraint that continues to be irresolvable by SCED. Effective January 1, 2015, the following changes to the set of constraints that are consistently irresolvable by SCED will be made: Contingency Name Constraint Name Description Current Maximum Shadow Price Maximum Shadow Price Effective 1/1/15 BASE CASE VALIMP Valley Import Base Case $2,000.00 $2,000.00 SSALSK28 6146__A Skywest to Salt Flat Road 138kV line overloads Midland East to Buffalo 138kv line $2,377.57 $2,481.67 STEJGR38 HEIGHTTN_HAT2 Tejas TNP to Greenbelt TNP (#38530 - #38575) 138kV line overloads Heights TNP Autotransformer 2 (#38740 - #38770) $2,000.00 $2,000.00 SMCEABS8 ABNW_ELYT1_1 Loss of the 138 kV lines from Eskota Switch to McElmurray Tap Switchyard to Potter LCRA to Abilene South and Potter LCRA to Moore_Taylor Electric Coop overloads the 69 kV line from Abilene Northwest to Ely Rea Tap $2,131.06 $2,780.38 SLA_RIO8 RIOHND_ERIOHND_1 Las Palma - Rio Hondo 138 kV line overloads the Rio Hondo - East Rio Hondo sub 138 kV Line $2,000.00 $2,000.00 SMDFHLT8 6596__F Bakke Tap to Unocal Parker Bakke 138 kV line overloads the 69 kV line from Emma Tap - Holt Switch $2,800.00 $2,800.00 SAPACAD8 HEIGHTTN_HAT1 Loss of the 138 kV line from Caddo Switching Station TNP to Apache TNP overloading the 138/69 kV Heights TNP Autotransformer #1 $2,000.00 $2,000.00 SLA_RIO8 HARLNS_OLEAND1_1 Las Palma - Rio Hondo 138 kV line overloads the Harlingen - Oleander 138 kV Line $2,000.00 $2,000.00 Additionally, effective January 30, 2015, the following constraints will no longer be considered irresolvable by SCED: Contingency Name Constraint Name Description DODEQAL5 6215__A Odessa - Morgan Creek / Quail Sw 345 kV overloads China Grove to Bluff Creek Switch 138 kV SSUNMGS8 6215__A Sun Switch to Morgan Creek SES 138 kV overloads China Grove Switch to Bluff Creek Switch 138 kV SNCWHLT9 6915__A Odessa North to Holt Sw 69 kV overloads Odessa Basin Sw - Odessa North 69 kV XMGS58 MGSES_MR1H Morgan Creek Autotransformer #4 345 kV/138 kV overloads Morgan Creek Autotransformer #1 345 kV/138 kV Section 3.6 of the business practice document requires a 30-day notice before the shadow price caps for SCED resolvable constraints are reset to their default values. The identified constraints will have their shadow price caps reset to their default shadow price cap values on January 30, 2015. ADDITIONAL INFORMATION: Per Section 3.6.3 of the business practice document, the net margin values for all of the constraints that are remaining as consistently irresolvable by SCED will be reset to zero on January 1, 2015. 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]<mailto:[log in to unmask]>. If you are receiving email from an 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. mm