NOTICE DATE:  January 5, 2009
NOTICE TYPE:  M-A010509-01 Operations
SHORT DESCRIPTION:  Update to Trading Hub Calculations due to 2009 Congestion Zones
INTENDED AUDIENCE:  Market Participants
DAY AFFECTED:  January 1, 2009
LONG DESCRIPTION:  ERCOT has updated the Trading Hub calculations for 2009.  Several transmission buses moved between Congestion Zones in the 2009 Commercially Significant Constraint definitions, approved by the Board on October 21, 2008.  While the buses that comprise the hubs remain the same, in accordance with Protocol Section 7.9.2, ERCOT Trading Hubs, the calculation for converting transactions at Trading Hubs to existing Congestion Zones is revised.  Market Participants should use the following table to convert transactions at Trading Hubs to existing Congestion Zones:


2009 Congestion Zone

Trading Hub

North

South

Houston

West

North

.976

0.024





South



0.97

0.03



Houston

0.050



0.950



West

0.235





0.765

Bus Average

0.571

0.221

0.123

0.085

ERCOT Average

0.315

0.249

0.245

0.191


A Protocol Revision Request will be submitted by ERCOT to update Section 7.9.3.4 accordingly.
ADDITIONAL INFORMATION:  ERCOT posts Trading Hub Prices for each ERCOT Trading Hub for each Settlement Interval as part of the Balancing Energy Service Report at http://www.ercot.com/mktinfo/services/bal/index.html.  This report will post today for January 1-4, 2009.
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 e-mail at [log in to unmask]<mailto:[log in to unmask]>.
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sg