NOTICE DATE: December 31, 2015

NOTICE TYPE: W-A123115-01 Operations

SHORT DESCRIPTION: Change to maximum shadow prices for constraints previously determined to be irresolvable by SCED

INTENDED AUDIENCE: ERCOT Market Participants

DAYS AFFECTED: January 1, 2016 and January 30, 2016

LONG DESCRIPTION: Section 3.6.2 of the Other Binding Document, Setting the Shadow Price Caps and Power Balance Penalties in Security Constrained Economic Dispatch, requires ERCOT, at the end of each calendar year, to review each constraint previously identified as irresolvable by Security-Constrained Economic Dispatch (SCED) and to (1) determine if the constraint has since become SCED-resolvable, and, if not, (2) re-determine the Shadow Price for the constraint.

Effective January 30, 2016, the following constraints will no longer be considered irresolvable by SCED:

Contingency Name	Constraint Name	From Station / kV	Description
SAPACAD8	HEIGHTTN_HAT1	HEIGHTTN / 138	Loss of the 138 kV line from Caddo Switching Station TNP to Apache TNP overloading the 138/69 kV Heights TNP Autotransformer #1
STEJGR38	HEIGHTTN_HAT2	HEIGHTTN / 138	Tejas TNP to Greenbelt TNP (#38530 - #38575) 138kV line overloads Heights TNP Autotransformer 2 (#38740 - #38770)

Additionally, effective January 1, 2016, the following changes to the shadow prices for the constraints that are consistently irresolvable by SCED will be made:

Contingency Name	Constraint Name	From Station / kV	Description	Current Maximum Shadow Price ($/MWh)	Maximum Shadow Price Effective 1/1/16 ($/MWh)
BASE CASE	VALIMP	N/A	Valley Import Base Case	$2,000.00	$2,000.00
SLA_RIO8	HARLNS_OLEAND1_1	HARLNSW / 138	Las Palma – Rio Hondo 138 kV line overloads the Harlingen – Oleander 138 kV Line	$2,000.00	$2,000.00
SLA_RIO8	RIOHND_ERIOHND_1	RIOHONDO / 138	Las Palma – Rio Hondo 138 kV line overloads the Rio Hondo – East Rio Hondo sub 138 kV Line	$2,000.00	$2,000.00
SMCEABS8	ABNW_ELYT1_1	ABNW / 69	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	$2,780.38	$2,000.00
SMDFHLT8	6596__F	HLTSW / 69	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
XSA2N89	SACH_69T1	SACH / 138	Loss of the San Angelo North 138/69 kV Auto transformer overloading the San Angelo College Hills 138/69 kV Auto transformer	$2,000.00	$2,000.00

Section 3.6 of the Other Binding Document requires 30 days’ notice before the shadow price caps for SCED-resolvable constraints are reset to their default values. For this reason, the identified constraints will have their shadow price caps reset to their default shadow price cap values on January 30, 2016.

ADDITIONAL INFORMATION: Per Section 3.6.3 of the Other Binding Document, the net margin values for all constraints that continue to be consistently irresolvable by SCED will be reset to zero on January 1, 2016.

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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