1 Wind Integration Study Team (WIST) Report to the Northwest Wind Integration Forum Technical Work Group October 29, 2009 Jeff Miller - ColumbiaGrid Rich Bayless - NTTG

2 Assignments from the Northwest Wind Integration Forum’s Wind Integration Action Plan –Assignment 1 –Assignment 1 – Determination of Dynamic Schedule Limits (DSLs) 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 –Assignment 2 –Assignment 2 – Evaluate development of Close In versus Remote 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 –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, –Large & varied participation –Kick off meeting March 5, 2009 –Liaison with WECC VGS WIST Assignments

3 WIST Activities Assignment 1 – Dynamic Schedule Limits – Staged analysis plan –Reviewed PowerEx Northern Intertie Study method and results –Study Plan Schedule to align with Joint Initiative DSS implementation schedule Initial DSLs for key flowgates on track –BPA performing analysis, Determining methodology, Identifying initial DSLs for sample key flowgates, Will then apply method to all Assignment 2 - Remote versus Close in Wind development - Review of issues & methods –Collection & comparison of wind characteristics (ColumbiaGrid Statistical Analysis) For NW wind zones Ramp rates, frequency, magnitude Diversity & correlation –Identification of technical & operational issues Regulation requirements & costs Transmission Costs –Assessment of models & methods to calculate full delivered costs IPC simplified model Plexos, Promod, PNNL Projects WECC TEPPC Garrison Pumped Storage Study, TransCanada CAES GE NREL West Connect Study WREZ model & studies Assignment 3 - Will be deferred until after methods & results from Assignment 2 are more developed

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 4

5 IPC Simplified Model & Analysis

6 WREZ Model & LBNL Analysis

7 Preliminary Conclusions Diversity does exist between NW wind areas Exists between multiple areas Remote wind has better capacity factors Ramp frequency and magnitudes are similar in all areas and define balancing and regulation requirements. Dynamic Schedule Limits are effected by a number of issues: Frequency of switching devices and duty RAS Arming Voltage dips, and Voltage Collapse Dispatcher Work Load Existing nomograms and System Operating Limits Resource expansion solely by wind to meet new load growth will likely require substantial new supplemental energy resources. Very preliminary indications are that Close In Wind development is more economical than Remote generation even with remote storage. Extremely dependent on: Location, cost, and other uses of transmission Supplemental fuel prices Renewable policies, Tax Credits, other subsidies & requirements

8 Going Forward –Continue to develop DSL limits to meet DSS Schedule in April 2010 –Continue to evaluate and use various models to more accurately analyze Remote versus Close In wind development - more accurately evaluate: Cost of balancing Sub-hourly reserve issues –Coordinate with WECC VGS and other ongoing efforts (avoid duplication) –Monitor and provide input into National Labs projects