1. Bulk Electric System Definition Task Force Update Reliability Policy Issues Committee March 4, 2010 Brian Theaker BESDTF Chair

2. Todays Update BES definition proposal Material Impact Assessment Schedule Questions 1.2

3. December 2009 RPIC Guidance Phase 1 – focus on what Elements are part of the BES Transmission voltage performance Targeting OC approval in June Phase 2 – evaluate how entities may impact BES reliability Generators Loads Scope and timing undefined 1.3

4. Recent Events Posted on February 12: Proposal 4 MIA status (Appendix A) BES white paper (Appendix B) Response to comments on P3 Comments on P4 due 3/17 1.4

5. Proposal 4 Reformatted for clarity, eliminate conflict Tightened up radial exemption < 200 kV, serving only load, not hard-tapped Distribution Networks Networks > 100 kV that serve load and do not provide meaningful flow-through Seeking to define in a way that would allow exclusion from BES without an MIA Struggling and seeking comment 1.5

6. Proposal 4 – (2) Points of demarcation Automatic fault interrupting device Is AFID part of BES? Complex connections (ring bus, breaker-and-a- half) Protection systems and PRC-004/005 1.6

7. Proposal 4 – (3) Exclude Elements not represented in WECC-SRWG Annual Study Plan Basecases Will be controversial - expect comments 1.7

8. Material Impact Assessment Process must be: Clear and objective Technically defensible Accessible Repeatable Concerns: Regulatory approval (NPCC experience) Burden on smaller entities without study capabilities Burden on WECC staff to review Administrative process – logging, renewal, etc. 1.8

9. Material Impact Assessment Phase 1 – focused on: Transmission voltage performance Classifying BES Elements Two approaches: Three-phase fault with delayed clearing Scan for significant and widespread impacts Short-circuit MVA 1.9

10. Material Impact Assessment (2) TSS review Discussed with TSS on 1/20 TSS has formed task force to consider Use of three-phase fault with delayed clearing Generator and load tripping inevitable How much / what kind of tripping is allowed? Can alternate approaches be combined? Use SCMVA approach as a screen to reduce number of simulation studies? 1.10

11. Schedule Fourth Proposal posted on 2/12 Presenting to joint MIC/OC/PCC meeting on March 11 Seeking OC feedback 1.11

12. Schedule (2) Continue to develop MIA TSS and BESDTF MIA small group Post MIA for 45-day comment period Seek OC approval of BES definition and MIA in June (?) Waiting for TSS input makes June impossible Six-month gap between October and March Phase 2 - TBD 1.12

13. Questions? For every complex problem there is an answer that is clear, simple, and wrong. H.L. Mencken Things should be made as simple as possible, but not any simpler. Albert Einstein Brian Theaker Chair, BESDTF brian.theaker@dynegy.com