Transmission Reliability: A West Perspective

1. Transmission Reliability: A West Perspective Chifong Thomas Principal Consulting Engineer, PG&E October 28, 2004 San Francisco

2. Technical Perspective • What is covered: • Technical steps that must happen in the planning process so the system reliability is preserved. • Transmission Planning perspective

3. Topics • Integrating resource planning and transmission planning processes - considerations and steps in planning transmission expansion • trade-off between transmission projects and resource addition/siting and other non-wire alternatives • WECC Path Rating Process – A collaborative reliability process

4. Resource Plan Load Forecast Transmission Plan Integrating Resource Planning & Transmission Planning Processes A multi-step iterative process

5. Resource Planning vs. Transmission Planning Processes Resources by technology and location Resources by Technology Aggregated Load + estimated losses Loads by Substation bus Generator Production costs Aggregated Imports/Exports Network Topology Import, Export Typical Power flow/ Stability Models Typical Production Simulation Models Some Merging of Technology Power Flows on Facilities Reliability Indices Marginal Costs losses Expected Portfolio Production Costs Bus voltages

6. Reliability NERC Glossary of Terms: Reliability: the degree of performance of the elements of the bulk electric system that results in electricity being delivered to customers within accepted standards and in the amount desired (measured by frequency, duration, and magnitude of adverse effects) • Adequacy • Security

7. Planning Standards • NERC/WECC Planning Standards • California ISO Grid Planning Criteria • Performance Categories: • Category A: N-0 • Category B: Single Contingencies (e.g., G-1, N-1) • Category C: Multiple/Overlapping Contingencies (e.g., N-2) • Category D: Extreme Contingencies http://www1.caiso.com/docs/2001/06/04/2001060418221123496.htmlTransmission Problem => When Planning Standards are not met

9. Transmission Planning Process • Assess system performance - Problem identification • Formulate potential alternative solutions • Narrow down to a few most promising alternatives • Evaluation of alternatives • Select the alternative for detailed studies • Recommend the solution • Go through WECC Process, if required • Go through permitting Process, if required

10. Define Scenarios • Start with established Load Projection and Resource Plan • Build Transmission System Scenarios – season, load level, Load distribution, Generation dispatch, transmission system configuration (reasonable adverse cases)

11. Load Duration Curve % of system Load % Time

12. Daily Load Curves Typical Summer Typical Winter % Load % Load Hour of Day Hour of Day

13. Study Areas

14. Transmission System Performance • Test system performance by running power flow and stability analysis: • Steady-state “normal” • Dynamic Stability • Steady-state post transient • Steady-state “emergency” • Compare against Planning Standards

15. Define Transmission Problem • Nature of problem (thermal overload, instability, cascading, etc.) • System conditions when problem may occur (N-0, N-1, G-1, etc.) • Magnitude, duration of the problem • Expected frequency of contingences • Consequence of problem

16. Formulate Alternative Solutions Typically, one or a combination of the following: • Operational Solutions (switching facilities, redispatch) • Nomograms • Remedial Action Schemes (Special Protection Schemes) • Reconfiguring transmission system • Demand Reduction • New generation facilities • Transmission Upgrades To be a viable solution, the alternative must enable system to meet Planning Standards

17. Develop Transmission Expansion Plan • Identify preliminary transmission projects => annual transmission expansion plan. (Update plan as projects are refined and approved) • For each preliminary project, perform detailed transmission planning studies • Determine trade-off between resources close to load vs. remote from load • Develop detailed Cost Estimates

18. Evaluate Viability of Alternatives • Operational Solutions (switching facilities, redispatch generation) • Pre-contingency or post-contingency • Automatic or manual • Speed • Coordination with other operation procedures • Hardware requirements

19. Evaluate Viability of Alternatives • Nomograms - Pre-contingency curtailment based on e.g., power flow on another path and system conditions: • Safe operating region • Coordination Issues • Hardware requirements Unstable Power Flow on Path B Stable Power Flow on Path A

20. Evaluate Viability of Alternatives • Remedial Action Schemes (RAS) • Speed • Security • Coordination with other protection schemes • Complexity • Consequences of misoperation Need: Approval by WECC RAS Reliability Task Force

21. MW Hours MW Hours Evaluate Viability of Alternatives • Demand Reduction • Location(s) and Magnitude • Timing (e.g., peak vs. off-peak) • System impacts • Pre-contingency/Post-contingency • Frequency and Duration • Voluntary/Involuntary • Load restoration • Hardware requirements

22. Evaluate Viability of Alternatives Generator must be running • New generation facilities • Central generating station • Distributed generation • Location • Magnitude • Coincidence with occurrence of transmission problem • Pre-contingency/post contingency • Interconnection requirements • System Impacts (WECC/ISO requirements) • Islanding issues • Within established Resource Plan? MW Hours Generation cannot avoid transmission problem MW Hours

23. Evaluate Viability of Alternatives • Transmission Upgrades • Network Reconfiguration • Reconductor existing line + substation equipment • New line + substation equipment • End points of new lines • Hardware requirements • Clearance requirements • System Impacts (e.g., upstream and downstream) • WECC Regional Planning and Rating Process

24. Approvals • Obtain internal approval • If the recommended alternative is generation addition => Resource RFO • If the recommended alternative is transmission addition => CAISO approval and CPUC permit process if needed. • “Significant” generation or transmission project needs to also follow WECC Process

25. WECC Processes • Regional Planning Review Process – applicable to transmission projects with Regional Significance • Path Rating Review Process – for transmission projects to obtain and accepted Path Rating (3 phases) • Progress Report Policies and Procedures – applicable to significant generation and transmission projects

26. WECC Regional Planning and Facility Rating Review Process • Transmission Projects: • Regional Planning Process • Rating Process if an Accepted Path Rating is desired or required “Procedures for Regional Planning Project Review and Rating Transmission Facilities”,December 2001, Revised May 21, 2002

27. WECC Processes Project Planning Process Formation Studies Licensing Construction Regional Planning Process Assessment, Project Review Rating Review Process Phase 1 Proposed Rating Phase 2 Planned Rating Phase 3Accepted Rating Stakeholder Participation Non-utility Input Review, Approval, and Compliance Monitoring Regulatory Process

28. WECC Regional Planning Process • Purpose: • Foster the development of a broad regional planning perspective among all stakeholders • Promote and encourage the most efficient use and development of existing and future facilities that enhance interconnected system operation • Assure that all relevant regional planning issues are considered during the planning of transmission projects.

29. Regional Planning Project Review • Occurs independently, but before Phase 1 of Rating Process can be completed • Requested by WECC-Planning Coordination Committee (PCC), or • Project sponsor, or • Affected member • Sponsor to form Regional Planning Review Group

30. Regional Planning Project Review • Sponsor writes a Regional Planning Report • Presents to PCC and Technical Studies Subcommittee (TSS), comments expected in 30 days • PCC concurs completion of process – determines project’s conformity with WECC Regional Planning Guidelines • PCC Chair sends announcement to PCC & TSS

31. WECC Progress Report Policies and Procedures • Project reporting before, during and after Path Rating Review Process • Required for Significant additions: • New & upgraded generation projects 200 MW or higher • New & upgraded transmission projects 200 kV or higher • Other with significant impact to reliability • Can include new, re-designs, upgrades, removals, operating procedure changes, etc. • Sponsor to demonstrate that the project is in compliance with the NERC/WECC Planning Standards.

32. WECC Progress Report Policies and Procedures • Initial Progress Report– TSS & WECC Staff • Soon after project is made public • Comprehensive Progress Report- TSS & WECC Staff • Soon enough to allow changes from member review & input • 10 minimum requirements listed • Supplemental Progress Reports • Review of Progress Reports & Projects • Presentations at TSS meetings

33. Path Rating Review Process • Objectives • Integrate projects while preserving reliability and efficiency • Communicate plans, performance & limitations • Discover simultaneous limitations & resolve • Participation in review of project studies • Conclude studies in a timely manner • Facilitate development of curtailment sharing agreements

34. Phase 1 - Path Rating Review Process • Begins with Announcement • Significant Additions Report, or • Letter of Notification to TSS, Staff & PCC, or • Initial Progress Report • ** Proposed Rating **

35. Phase 1 - Path Rating Review Process • Completed when: • Regional Planning Report accepted by PCC • Modeling given to WECC Staff for WECC base cases • Comprehensive Progress Report • Given to TSS, WECC Staff & PCC • Minimum 60 day review after received by Staff • Staff record of Member comments are resolved, or • Project Sponsor agree to resolve outstanding issues in Phase 2

36. Phase 1 - Path Rating Review Process • Upon Request by Project Sponsor, TSS Chair • Checks with Staff on comments and resolution • Notifies PCC and TSS • Acceptance of Comprehensive Progress Report (not approval)

37. Phase 2 - Path Rating Review Process • ** Planned Rating ** • Considered on equal basis where similarly situated in Phase 2 • Letter sent by project sponsor to WECC Staff, TSS, PCC, and Operating Committee (OC) requesting interest in participating in a Review Group • Members have 30 days from date letter is received by Staff to respond with expression of interest

38. Phase 2 - Path Rating Review Process • Review Group purpose • Demonstrate Project meets Planning Standards • Identify non- and simultaneous path limits • Address mitigation of simultaneous limits • Resolve comments on Comprehensive Progress Report

39. Phase 2 - Path Rating Review Process • Completed when • Project Sponsor issues Phase 2 Rating Report • 60 day Review Group review after Staff receives • Staff record of Review Group comments are resolved • Upon request by the Sponsor, PCC Chair notifies PCC, TSS, and OC • Checks with WECC Staff on comments and resolution • Acceptance of Phase 2 Rating Report (not approval) • Project has entered Phase 3

40. Phase 3 - Path Rating Review Process • ** Accepted Rating ** • Monitoring Project Progress, at risk if: • Fails to complete plan of service • Failure of other projects required for rating • Failure to follow schedule (> 12 month delay) • Completed when • Construction is complete • Operating procedures are accepted • Placed in operation

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