Northwest Wind Integration: Dynamic Transfer Limits and Remote vs. Local Wind Development

1. Wind Integration Study Team (WIST) Report to the Northwest Wind Integration Forum Steering Committee January 6, 2010 Jeff Miller - ColumbiaGrid Rich Bayless - NTTG

2. WIST Assignments • Assignments from the Northwest Wind Integration Forum’s Wind Integration Action Plan • Assignment 1 – Determination of Dynamic Transfer Limits (DTLs) on NW Flowgates: • Along with the Joint Initiative for sub-hourly scheduling, NWIF asked that CG & NTTG jointly assess technical impacts & cost effectiveness of increasing dynamic scheduling capabilities across • Key NW Balancing Authority interfaces, • Northern & Southern Interties • Internal BPA Flowgates • Assignment 2 – Evaluate development of Remote versus Local wind: • NTAC (subsequently CG & NTTG) should propose a methodology to assess developing wind on a more broad geographic basis versus close in • Identify full delivered costs including the costs of balancing & transmission • Assignment 3 – Transmission Planning Methodology for Variable Generation • CG & NTTG should develop & apply a Variable Resource Transmission Planning Methodology for the Northwest • WIST is a technical committee facilitated by CG & NTTG • Open to all interested parties • Monthly meetings, • Volunteered labor and time • Large & varied participation • Kick off meeting March 5, 2009 • Liaison with WECC VGS

3. Assignment 1 – Dynamic Schedule Limits Staged analysis plan Initiated from PowerEx Northern Intertie Study - method and results Study Plan Schedule to align with Joint Initiative DSS implementation schedule DTLs for key flowgates still on track Coordination with DSS operating protocols BPA performing analysis, BPA developing the method and analysis automation Study Team review of methods, assumptions, overall results Review and analysis of specific BA flowgate results by involved transmission owners PSE, NWE, BCTC, PowerEx, IPC Initial DTLs Conservative To meet timeline Unknown territory Goal to increase DTLs down the road Test and modify assumptions, refine methodology Determine, implement system fixes DSL Coordination with other Western Interconnection areas WestConnect, WECC VGS CaISO Dynamic Transfer initiative 3

4. Dynamic Schedule Limit Analysis • Paths/Flowgates under study: • California-Oregon Intertie (COI) • Northern Intertie • West of Garrison • NW-to-Idaho (LaGrande) • West of Cascades – North • West of Cascades - South • North of Hanford • North of John Day • South of Allston • West of McNary • West of Slatt • Voltage Support Equip Response

5. Preliminary Conclusions - DTLs • COI 4800 MW Example (preliminary) • Calculated Variability Limit = 531 MW • If used for Dynamic Transfers then • ATC = 4800 – 531 MW = 4261 MW for other scheduled transfers • North Of Hanford Example (preliminary) • DTL = (Calc Variability Limit) – (Historical Use) – (Reliability Margin) • DTL = 500 MW – 200 MW – 100 MW = 200 MW • Outages or other system conditions could reduce the DTL, as real-time reliability concerns demand

6. Assignment 2 - Remote Versus Local Wind Development • Collection & comparison of wind characteristics for NW various wind zones • ColumbiaGrid, BPA, IPC provided analysis using NREL and BPA data • Energy and Capacity Factors • Diversity & correlation with loads • Regulation and Load Following Characteristics • Ramp rates, frequency, magnitude • Identification of technical & operational issues • Energy and capacity • Regulation requirements & costs • Transmission operating effects and Costs • Assessment of models & methods to calculate full delivered costs • IPC simplified model • Production Cost Models, Plexos, Promod, PNNL Projects • WECC TEPPC & Garrison Pumped Storage Study, TransCanada Compressed Air Energy Storage • GE NREL West Connect Study • WREZ model & studies

7. IPC Model & Analysis January Load vs Wind -2006 NREL 10 min wind data -2006 IPC Load shape -Diverse Wind generation: 1/3 Gorge, 1/3 Wyo, 1/3 Mont Wind MW July Load vs Wind Load MW • 12 month analysis showed: • For 1000 MW load addition served by 1000 MW wind additions , • 970 MW of fast responding additional generation would be needed (4x greater than historic reg requirements) • to meet LOLP and reliability requirements Wind MW Load MW

8. WREZ Model & LBNL Analysis

9. Prelim Conclusions – Remote vs Local Diversity does exist between NW wind areas Eastern NW wind has better capacity factors Wind capacity not well correlated with coastal loads Within hour Ramp frequency and magnitudes are similar in all areas Regulation and balancing requirements similar Resource expansion solely by wind to meet new load growth will likely require substantial new supplemental energy resources. Preliminary indications are that Local Wind development is more economical than Remote generation even with remote storage. Extremely dependent on: Transmission cost is a big factor Location, cost, and other uses of transmission Supplemental fuel prices Renewable policies, Tax Credits, other subsidies & requirements 9

10. Going Forward • WIST to continue to develop DTL limits to meet DSS Schedule - Summer/Fall 2010, and continue other DTL activities • Change WIST Assignment Two on Remote versus Local Generation • Further analysis on Assignment 2 (Remote vs Local) requires additional resources • Modeling tools and studies • Additional volunteering of staff resources and $$. • Other Similar Studies Underway • BPA, WREZ, National Labs, and WECC VGS • DOE grants for Remote versus Local and Regulation Requirements studies • WIST functions well as an open review forum • WIST should change to become an Open Stakeholder Technical Review Forum to review and critique ongoing technical studies regarding renewables effecting the NW. • Relationship to other NW Work Groups • Assignment 3 - Will be deferred until after results from Assignments 1 & 2 • Recommendations or direction from the NWIF SC?