ColumbiaGrid Planning Update to PCC Marv Landauer October 7, 2014

Variable Transfer Limit Studies for COI Regional Planning Processes Order Biennial Plan Economic Planning Studies ColumbiaGrid Planning 2

Avista Corporation Bonneville Power Administration Chelan County PUD Cowlitz County PUD Douglas County PUD Enbridge Grant County PUD Puget Sound Energy Seattle City Light Snohomish County PUD Tacoma Power 3 Members and Planning Participants

4 Variable Transfer Limit Study for COI Updates to VTL numbers for EIM implementation Utilizing collaborative methodology developed last spring 

1. Customer Service Impacts  Acceptable voltage ranges for transmission busses 2. System Equipment Impacts  No manual operation of equipment especially RAS within the scheduling period 3. Reliability Impacts  Contingency analysis of critical points from #1 and #2 VTL Methodology 5

6 VTL Study for COI Power Engineers is performing the study State Estimator cases used as starting points Analyzing 2-week periods for 3 seasons  Spring (for Fall and Spring operations)  Winter  Summer

7 VTL Study for COI (cont) Approximately 300+ cases per season For COI study, simulate transfer between CA/PNW  CA generation: Midway and Bay Area  PNW generation: Gorge wind and Mid Columbia hydro Ongoing study, anticipated completion – Oct 2014

8 WECC Regional Planning 1. Central Ferry-Lower Monumental Planning Review Group 2. PDCI Upgrade Project Rating 3. West of McNary Reinforcement Rating Process

9 Order FERC responded to ColumbiaGrid filing on September ColumbiaGrid is comprised of both jurisdictional and non-jurisdictional members 3. Cost allocations are binding to enrolled members 4. Non-jurisdictionals can choose to enroll days to refile with FERC

10 Biennial Plan Sensitivity Studies Four sensitivity studies are ongoing  Comprehensive N-1-1 outages study  NW Washington Load Area IROL verification in the planning horizon  Post Contingency voltage angle differences  Maximum area generation during light load The study results will be presented in upcoming planning meetings and included in the next Biennial Plan

11 Economic Planning Study Backcast 2010:  Backcast power flow on key paths within WECC  West of Cascades North and South, Montana to NW, Idaho to NW, COI, PDCI, WOR,..  Input actual loads, fuel cost, transmission system,  Learn what modeling techniques are required to mimic historic operations Forecast 2014, and 2017:  Apply lessons learned in the backcast to the forecast runs.  This assumes that future operations will mimic historic operations  Compare loading of lines/paths, congestion, change in flow patterns and area losses

Economic Planning Study Coal Retirement Study:  Evaluate location impact of replacement capacity for Centralia on the Pacific Northwest transmission system  Three areas are being considered for replacement capacity: Centralia area, North of Seattle, and Stanfield Area (McNary to Boardman)  Replacement capacity is assumed to be combine cycle  Run with 2017 loads: This eliminates the need to install new capacity to meet load growth and reserves for 2024 (+19,000 MW of additional supply)  Include announced Coal retirements, replacement projects and fuel conversion to NG (impacting 6,500 MW of ST-Coal from 2013)  Include California Once Through Cooling retirements  Sensitivities on potential retirement of Colstrip 1&2 and additional wind in Montana

Questions?