1. Western Area Power Administration Transmission Customer Meeting October 17, 2007

2. Western Area Power Administration AGENDA: POWER OPERATIONS UPDATE General Update 890 Filing Darren Buck, Power Operations Manager ATC Calculations Mariam Mirzadeh, Transmission Planning Engr. Rates Update Sean Sanderson, Rates Manager

3. Physics of Disturbances Thermal Overloads Voltage Limits System Stability Transient Voltages Frequency Limits Damping VARs and Voltage Stability Remedial Action Schemes System Synergy Islanding Cascading Western Area Power Administration

4. Transfer Capability Limit Criteria Total Transfer Capability (TTC) Maximum amount of power that can be transferred across an interconnection or a transfer path from one control area to another or within an area while ensuring that the transmission system is able to suffer and recover from a severe outage (meeting the NERC/WECC reliability criteria). Net schedules shall not exceed TTC TTC & ATC are directional Operating Limits No element shall be scheduled above it’s continuous operating limits Western Area Power Administration

5. Stability Following an Outage N-1s shall not cause cascading System Response to Contingencies Prior to Readjustment (Transient period) Voltages and element loading shall meet the WECC/NERC corresponding criteria, loading shall not exceed emergency ratings Western Area Power Administration Transfer Capability Limit Criteria Cont’d

6. Available Transfer Capability (ATC) – OATT & Mandatory Reliability Requirements

7. Western Area Power Administration ATC = TTC (allocated to Western) – Committed Uses Where Committed Uses = Existing Transmission Commitments + Transmission Reliability Margin (TRM) + Capacity Benefit Margin (CBM) TRM Includes: Unscheduled Flow (Loop Flow) Accommodation for any simultaneous limitations associated with operation under a nomogram & Uncertainty in load forecasting – regulation, etc.

8. CBM Includes: Capacity for movement of water in order to meet Bureau of Reclamation/Corp of Engineers water schedules, or for moving generation under black starts conditions. All transmission (PACI, COTP, network and P-P) reservations are subject to real-time operation operating limitations especially the Sacramento area simultaneous import Nomogram. Western Area Power Administration

9. CVP Network transmission ATC calculation methodology, SNR business practice # 20: https://www.westtrans.net/WASN/WASNdocs/CVP_Trans _BP-20_V_01_10-15-07.pdf OATT: http://www.oatioasis.com/WASN/WASNdocs/tariff_mast ercopy_(11_05).pdf Rates: http://www.wapa.gov/sn/marketing/rates/ http://www.wapa.gov/sn/marketing/rates/

10. Questions/Discussion Western Area Power Administration