Transmission Facility Ratings

1. Transmission Facility Ratings Presentation to the Reliability CommitteeJune 14, 2005

2. Today’s Agenda Review and Vote: • New Planning Procedure No. 7 (PP-7) - Including Appendices A and C • Revised Operating Procedure No. 16 Supporting Materials: • ISO Rating Collaboration Req’ts Report - basis for new PP and some OP16 changes • SDTF Ambient Temperatures and Wind Velocities Report - documents “benchmark” values of PP-7

3. April RC Meeting Recap Why have rating procedures ? • RTO Transmission Operating Agreement • Section 3.06(a)(v): “Each Participant Transmission Owner shall collaborate with the ISO with respect to: • the development of Rating Procedures • the establishment of ratings …” • NERC Reliability Std (FAC-004-0/FAC-008-1) • The Transmission Owner and Generator Owner shall each document its methodology used for developing Facility Ratings…

4. April RC Meeting Recap Meeting the New Requirements… • New Planning Procedure No. 7 (PP-7) • “Best Practices” approach to rating procedures and ISO/SDTF review of NX-9 rating data • Roles/responsibilities of SDTF and ISO in each • CRPs rewritten as “Best Practices”, attached as appendices and maintained by SDTF • Provide for “Accepted Alternative Rating Practices” • Where are we now: • RC vote “to recommend support”

5. April RC Meeting Recap Meeting the New Requirements… • Modifications to OP-16 • Enforce existing requirements • Involve ISO (and SDTF) in establishing ratings • Meet NERC Reliability Standard FAC-009-1, Establish and Communicate Facility Ratings • Where are we now: • RC vote “to recommend support”

6. Since April Addressed RC Comments on PP-7: • References, add NERC Reliability Standard FAC-008-1 • Section 1.4, reworded ISO Responsibilities • Section 1.6 (new), addressed static and dynamic ratings • Attachment 1 (new), provided repository of “Accepted Alternative Rating Practices” • Appendix A, prepared report documenting temperature statistics and wind velocities, use of a single ambient temperature for all NE, and choice of Hartford data as being representative of all NE • Appendix C, clarified that methodology applies to both underground and submarine cables

7. Since April NERC Reliability Standards: • Reviewed PP-7 for conformance with FAC-008-1, Facility Ratings Methodology (will replace FAC-004-0) • Section 2.5, revised to clarify actions, responsibilities and timelines Eliminated Duplicative Requirements • Refers to OP16 for periods for which Summer and Winter ratings apply • Refers to OP19 for time durations to be used in calculating and applying Short- and Long-Time Emergency ratings

8. Ambient Temperatures and Wind Velocities Report • Documents Ambient Temps and Wind Used • Reaffirms Established Ambient Temperatures • 1975-2004 vs. 1905-1970 Hartford area data: same result • Hartford area similar to 1975-2004 average of 8 locations • Data provides no basis for carving NE into well-defined temperature zones • Largest temperature differences up to 3 to 4 °C • Affect 115kV line ratings by <2%; 345kV line ratings by <4%

9. PP-7 Implementation Schedule NERC FAC-008-1 Compliance Date NPCC Compliance Audit expected ISO Initiates Request for MP Rating Methodologies [2.5.1] ISO Reviews MP Responses, Solicits SDTF Advice [2.5.5, 2.5.7] 60 days Complete PP-7 Appendices SDTF Recommendations To ISO [2.5.5] ISO Acts on Recommendations: • Approve and Record Accepted Alternative Rating Practices • Initiate Disagreement Discussions [2.5.6] MP Responses Due: • Methodologies • Inputs/Assumptions • Differences from Best Practices • Schedule to Conform Or Justification for Practice [2.5.5 thru 2.5.7] PP-7 Appendices Approved and Posted