1 ColumbiaGrid Update June 27, 2008

Activities Planning OASIS Redispatch 2

3 Biennial Transmission Expansion Plan

4 System Assessment Completed Leading 3 study teams –Puget Sound Area –Olympic Peninsula –Northern Mid-C Initiating 6 sensitivity studies –Increased wind –low hydro –Cowlitz looped operation –Gas curtailment –Higher California transfers –Centralia out. Next Planning Meeting is July 10 th Biennial Plan

5 Planning Area Loads Legend MW in 2008 MW in 2018

6 Multi-System Violations requiring action this planning cycle Multi-System Violations Involving only one CG Party Future Needs Single System Needs

7 Wind Resources Wind Growth Legend Operating or Under Construction Proposed or in Queue

8 1.Met on May 20 th 2.Reviewed 2008 summer operating nomogram studies. 3.Analyzing the ability of the transmission system to simultaneously meet both local customer reliability needs and Canadian transfer requirements Study is being initiated to examine the effect that several potential transmission additions will have on reducing the likelihood of curtailments Study Plan approved at May 20 th meeting CG Staff is developing base cases for study Working on automating the simulations to speed up study work 4.Working with Seattle City Light to develop expansion plans to address reliability concerns in the Northern downtown Seattle area. Several alternatives under consideration Solution selected by SCL will be analyzed in #1 above 5.Acting as the WECC Project review group for the BCTC proposed Northern Intertie rating increase South to north only From 2000 MW to as high as 3000 MW Joint BCTC/ColumbiaGrid notice was sent out to WECC on April 25 th Study plan reviewed by group at May 20 th meeting Puget Sound Area Study Team

9 OASIS Program Goal is to have single OASIS interface that spans multiple transmission systems to improve customer access to transmission service. New Functional Agreement effective April 1, 2008 Participants: Avista, BPA, Chelan PUD, Grant PUD, Puget Sound Energy, Seattle City Light, Snohomish PUD, Tacoma Power Currently hiring staff to begin program.

: 1.Develop common ATC methodology 2.Facilitate development of common queues for transmission service and interconnection requests 3.Develop plan for a common web-based OASIS portal 2009 and beyond: 1.Implement common OASIS portal that points to participants individual OASIS platforms. 2.Implement common ATC methodology and common queues OASIS Program Schedule

Redispatch Program Improves the efficient use of the grid by increasing transmission capability through the selective redispatch of generation Helps to bridge problems until transmission can be built ColumbiaGrid effort: –Builds on current BPA redispatch program –Looking to expand program across control area boundaries to include more generator participants and increase benefits –May implement independent intra-hour energy bid market to facilitate redispatch and act as energy balancing source. This may be particularly useful in integrating wind generation. Collaborative work to continue 11

12 Questions?