NOTICE DATE: July 30, 2012

NOTICE TYPE: W-A073012-01 Operations

SHORT DESCRIPTION: Change to (HCAP) effective on Operating Day August 1, 2012

INTENDED AUDIENCE: ERCOT Market Participants

DAY AFFECTED: August 1, 2012

LONG DESCRIPTION: In accordance with Public Utility Commission of Texas (PUCT) Substantive Rule 25.508, High System-Wide Offer Cap in the Electric Reliability Council of Texas Power Region, the High System-Wide Offer Cap (HCAP) will be $4,500 for Energy and Ancillary Services beginning on Operating Day August 1, 2012.

Note that offer submittals at the new HCAP take effect only for submissions starting at 00:01 Central Prevailing Time (CPT) on Operating Day August 1, 2012.

ADDITIONAL INFORMATION: See the ‘System-Wide Offer Cap and Scarcity Pricing Mechanism Methodology’ ERCOT Business Practice for further details. This document is located in the Other Binding Documents List on ERCOT.com at http://www.ercot.com/mktrules/obd/obdlist.

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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