Forward to the Revised Draft 2014-2015 Transmission Plan This revised draft transmission plan reflects a number of changes from the draft plan released on February 2, 2015. To assist our stakeholders following the transmission plan cycle, we have summarized a number of those changes: The model estimating the impact of the transmission plan on the ISO’s High Voltage TAC has been updated and the results added to the model. The ISO has confirmed with Duke American Transmission Company that DATC’s request window submission for the San Luis Transmission Project was sent, but not received on the original request window submission timeline. It has subsequently been resent and received by the ISO. Accordingly, the plan has been revised to incorporate the review of the to the request window submission. A number of clarifications and edits have been added throughout the plan to address other stakeholder comments. 2014-2015 ISO Transmission Plan March 19, 2015 Table of Contents Executive Summary ..................................................................................................... 1 Introduction ...................................................................................................... 1 The Transmission Planning Process ................................................................ 3 Collaborative Planning Efforts .......................................................................... 4 Advancing Preferred Resources ....................................................................... 6 Reliability Assessment ...................................................................................... 7 33 Percent RPS Generation Portfolios and Transmission Assessment ............. 8 Economic Studies ........................................................................................... 12 Conclusions and Recommendations .............................................................. 12 Chapter 1 ................................................................................................................... 14 1 Overview of the Transmission Planning Process ............................................ 15 1.1 Purpose ........................................................................................ 15 1.2 Structure of the Transmission Planning Process ........................... 18 1.2.1 Phase 1 ................................................................................... 18 1.2.2 Phase 2 ................................................................................... 21 1.2.3 Phase 3 ................................................................................... 23 1.3 Interrelated Processes and initiatives ............................................ 25 Chapter 2 ................................................................................................................... 32 2 Reliability Assessment – Study Assumptions, Methodology and Results ........ 33 2.1 Overview of the ISO Reliability Assessment .................................. 33 2.1.1 Backbone (500 kV and selected 230 kV) System Assessment ............................................................................. 33 2.1.2 Regional Area Assessments .................................................... 33 2.2 Reliability Standards Compliance Criteria...................................... 35 2.2.1 NERC Reliability Standards ..................................................... 35 2.2.1.1 System Performance Reliability Standards (TPL-001 to TPL-004) .. 35 2.2.2 WECC Regional Criteria .......................................................... 35 2.2.3 California ISO Planning Standards .......................................... 35 2.3 Study Methodology and Assumptions ........................................... 36 2.3.1 Study Methodology .................................................................. 36 2.3.1.1 Generation Dispatch ....................................................................... 36 2.3.1.2 Power Flow Contingency Analysis .................................................. 36 2.3.1.3 Transient Stability Analyses ............................................................ 36 2.3.2 Preferred Resources Methodology .......................................... 37 2.3.3 Study Assumptions .................................................................. 38 2.3.3.1 Study Horizon and Study Years ...................................................... 38 2.3.3.2 Peak Demand ................................................................................. 38 California ISO/MID i 2014-2015 ISO Transmission Plan March 19, 2015 2.3.3.3 Stressed Import Path Flows ............................................................ 41 2.3.3.4 Contingencies ................................................................................. 41 2.3.3.5 Generation Projects ........................................................................ 42 2.3.3.6 Transmission Projects .................................................................... 43 2.3.3.7 Load Forecast ................................................................................ 43 2.3.3.8 Reactive Power Resources ............................................................ 43 2.3.3.9 Operating Procedures..................................................................... 44 2.3.3.10 Firm Transfers ................................................................................ 44 2.3.3.11 Protection Systems ......................................................................... 46 2.3.3.12 Control Devices .............................................................................. 46 2.4 Northern California Bulk Transmission System Assessment ......... 47 2.4.1 Northern California Bulk Transmission System Description ..... 47 2.4.2 Study Assumptions and System Conditions ............................ 48 2.4.3 Assessment and Recommendations ....................................... 51 2.5 PG&E Local Areas Assessment .................................................... 55 2.5.1 Humboldt Area ........................................................................ 55 2.5.1.1 Area Description ............................................................................. 55 2.5.1.2 Area Specific Assumptions and System Conditions ........................ 55 2.5.1.3 Assessment and Recommendations ............................................... 57 2.5.2 North Coast and North Bay Areas ........................................... 59 2.5.2.1 Area Description ............................................................................. 59 2.5.2.2 Area-Specific Assumptions and System Conditions ........................ 59 2.5.2.3 Assessment and Recommendations ............................................... 61 2.5.3 North Valley Area .................................................................... 63 2.5.3.1 Area Description ............................................................................. 63 2.5.3.2 Area-Specific Assumptions and System Conditions ........................ 63 2.5.3.3 Assessment and Recommendations ............................................... 64 2.5.4 Central Valley Area ................................................................. 66 2.5.4.1 Area Description ............................................................................. 66 2.5.4.2 Area-Specific Assumptions and System Conditions ........................ 67 2.5.4.3 Assessment and Recommendations ............................................... 68 2.5.5 Greater Bay Area .................................................................... 69 2.5.5.1 Area Description ............................................................................. 69 2.5.5.2 Area-Specific Assumptions and System Conditions ........................ 70 2.5.5.3 Assessment and Recommendations ............................................... 71 2.5.6 Greater Fresno Area ............................................................... 74 2.5.6.1 Area Description ............................................................................. 74 2.5.6.2 Area-Specific Assumptions and System Conditions ........................ 74 2.5.6.3 Assessment and Recommendations ............................................... 76 California ISO/MID ii 2014-2015 ISO Transmission Plan March 19, 2015 2.5.7 Kern Area ................................................................................ 77 2.5.7.1 Area Description ............................................................................. 77 2.5.7.2 Area-Specific Assumptions and System Conditions ........................ 77 2.5.7.3 Assessment and Recommendations ............................................... 78 2.5.8 Central Coast and Los Padres Areas ...................................... 81 2.5.8.1 Area Description ............................................................................. 81 2.5.8.2 Area-Specific Assumptions and System Conditions ........................ 82 2.5.8.3 Assessment and Recommendations ............................................... 83 2.6 Southern California Bulk Transmission System Assessment ......... 85 2.6.1 Area Description ...................................................................... 85 2.6.2 Area-Specific Assumptions and System Conditions ................ 87 2.6.3 Assessment and Recommendations ....................................... 93 2.6.3.1 Conclusions and Assessments ....................................................... 93 2.6.3.2 Preferred Resources Assessment (Non-Conventional Transmission Alternative