ColumbiaGrid Planning Update to PCC Marv Landauer October 7 , 2014

1. ColumbiaGrid Planning Update to PCCMarv LandauerOctober 7, 2014

2. ColumbiaGrid Planning Variable Transfer Limit Studies for COI Regional Planning Processes Order 1000 2015 Biennial Plan Economic Planning Studies

3. Members and Planning Participants • 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

4. Variable Transfer Limit Study for COI • Updates to VTL numbers for EIM implementation • Utilizing collaborative methodology developed last spring • http://www.columbiagrid.org/download.cfm?DVID=3570

5. VTL Methodology 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

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 • Central Ferry-Lower Monumental Planning Review Group • PDCI Upgrade Project Rating • West of McNary Reinforcement Rating Process

9. Order 1000 • FERC responded to ColumbiaGrid filing on September 18. • ColumbiaGrid is comprised of both jurisdictional and non-jurisdictional members • Cost allocations are binding to enrolled members • Non-jurisdictionals can choose to enroll • 60 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

12. 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

13. Questions?