NOTICE DATE:  July 22, 2015

NOTICE TYPE: W-A072215-01 Operations

SHORT DESCRIPTION:  Implementation of maximum shadow price for an irresolvable constraint in SCED

INTENDED AUDIENCE:  ERCOT Market Participants

DAY AFFECTED:  July 22, 2015

LONG DESCRIPTION: On July 22, 2015, ERCOT is implementing a modified maximum shadow price for a constraint that was found to be irresolvable per the criteria defined in Section 3.6.1 of the business practice document, “Setting the Shadow Price Caps and Power Balance Penalties in Security Constrained Economic Dispatch.” The contingency/constraint pair and maximum shadow price (set in accordance with Section 3.6.2 of that same document) are as follows:

Contingency Name	Constraint Name	From Station / kV	Description	Maximum Shadow Price
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

This maximum shadow price will be used for all constraints in SCED sharing the same monitored element (i.e. constraint name) and direction.

ADDITIONAL INFORMATION:  The business practice document is posted under Key Documents on the Real-Time Market webpage.

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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