NOTICE DATE: December 15, 2009 NOTICE TYPE: W-A121509-01 Operations SHORT DESCRIPTION: ERCOT Frequency Bias change for 2010 INTENDED AUDIENCE: QSE Operations Personnel DAY AFFECTED: January 5, 2010 LONG DESCRIPTION: The ERCOT Frequency Bias will change to 667 MW/0.1 Hz on January 5, 2010, and will remain effective until further notice. The current ERCOT Frequency Bias of 660 MW/0.1 Hz will remain in effect through January 4, 2010. 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]>. If you are receiving e-mail 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<http://lists.ercot.com/>. dh