Draft2013-2014TransmissionPlan

1 2017 -2018 TRANSMISSION PLANM arch 22 1 Board ApprovedForeward to Board-Approved 2017 -2018 Transmission Plan At the March 22, 2018 ISO Board of Governors meeting, the ISO Board of Governors approved the 2017 -2018 Transmission Plan. 2017 -2018 ISO Transmission Plan March 22, 2018 California ISO/MID i Table of Contents Executive Summary .. 1 The Transmission Planning Process .. 3 Planning Assumptions and State Agency Coordination .. 4 Key Reliability Study Findings .. 5 Renewables Portfolio Standard Policy-driven Transmission Assessment .. 7 Key Economic Study Findings .. 8 Non-Transmission Alternatives and Preferred 10 Informational Studies .. 10 Conclusions and Recommendations .. 11 Chapter 1 .. 13 1 Overview of the Transmission Planning Process .. 13 Purpose .. 13 Impacts of the Industry Transformation .. 16 Load Forecasting and Distributed Energy Resources Growth Scenarios .. 17 Resource Planning .. 19 System Modeling, Performance, and Assessments.

2 29 Structure of the Transmission Planning Process .. 31 Phase 1 .. 31 Phase 2 .. 33 Phase 3 .. 35 Interregional Transmission Coordination per FERC Order No. 1000 .. 37 ISO Processes coordinated with the Transmission Plan .. 39 Chapter 2 .. 43 2 Reliability Assessment Study Assumptions, Methodology and Results .. 43 Overview of the ISO Reliability Assessment .. 43 Backbone (500 kV and selected 230 kV) System Assessment .. 43 Regional Area Assessments .. 44 Peak Demand .. 44 Reliability Standards Compliance 45 NERC Reliability Standards .. 45 WECC Regional Criteria .. 45 California ISO Planning Standards .. 45 2017 -2018 ISO Transmission Plan March 22, 2018 California ISO/MID ii Study Assumptions and Methodology .. 46 Study Horizon and Years .. 46 Transmission Assumptions .. 46 Load Forecast Assumptions .. 47 Generation Assumptions .. 50 Preferred Resources .. 58 Firm Transfers.

3 64 Operating Procedures .. 65 Study Scenarios .. 65 Contingencies .. 70 Study Methodology .. 72 PG&E Bulk Transmission System Assessment .. 75 PG&E Bulk Transmission System Description .. 75 Study Assumptions and System Conditions .. 76 Assessment and Recommendations .. 81 PG&E Local Areas .. 90 Humboldt Area .. 90 North Coast and North Bay Areas .. 95 North Valley Area .. 105 Central Valley Area .. 111 Greater Bay Area .. 121 Greater Fresno Area .. 133 Kern Area .. 146 Central Coast and Los Padres Areas .. 153 California High Speed Train Project Load Interconnection .. 162 Southern California Bulk Transmission System Assessment .. 167 Area Description .. 167 Area-Specific Assumptions and System Conditions .. 169 Assessment Summary .. 171 Request Window Project Submissions .. 172 Consideration of Preferred Resources and Energy Storage .. 172 Recommendation .. 172 SCE Local Areas Assessment.

4 173 SCE Tehachapi and Big Creek Area .. 173 North of Lugo Area .. 177 SCE East of Lugo Area .. 181 SCE Eastern Area .. 184 SCE Metro Area .. 188 Valley Electric Association Area .. 197 Area Description .. 197 Area-Specific Assumptions and System Conditions .. 197 Assessment Summary .. 199 Request Window Project Submissions .. 199 Consideration of Preferred Resources and Energy Storage .. 200 Recommendation .. 200 SDG&E Area .. 201 San Diego Local Area Description .. 201 Area-Specific Assumptions and System Conditions .. 201 2017 -2018 ISO Transmission Plan March 22, 2018 California ISO/MID iii Assessment Summary .. 204 Request Window Project Submissions .. 204 Operational Modification and RAS Mitigations .. 208 Consideration of Preferred Resources and Energy Storage .. 209 Cancellation of Previously-Approved Projects .. 210 Recommendation .. 211 Balancing Authority Area Requirements - Phasor Measurement Units on ISO Interties.

5 212 Chapter 3 .. 213 3 Policy-Driven Need Assessment .. 213 Study Assumptions and Methodology .. 213 33% RPS Portfolios .. 213 Chapter 4 .. 219 4 Economic Planning Study .. 219 Introduction .. 219 Technical Study Approach and Process .. 220 Study Steps of Production Cost Simulation in Economic Planning .. 222 Production cost simulation tools and database .. 224 ISO Production Cost Model Development .. 225 Modeling assumptions .. 225 Network modeling .. 225 Load demand .. 225 Generation resources .. 226 Transmission constraints .. 226 Renewable curtailment 227 Financial Parameters Used in Cost-Benefit Analysis .. 228 Cost analysis .. 228 Benefit analysis .. 229 Cost-benefit analysis .. 229 Congestion Analysis Results .. 230 Economic Planning Study 237 Southwest Intertie Project - North .. 237 Bob SS to Mead Upgrade .. 239 Mira Loma Red Bluff 500 kV line .. 239 Devers Suncrest 500 kV line.

6 241 Renewable Energy Express .. 243 Round Mountain Cottonwood 230 kV Project .. 245 SunZia and 1500 MW Wind in New Mexico .. 246 LCR Benefit Evaluation: South Bay-Moss Landing, Wilson, LA Basin, San Diego/Imperial Valley .. 248 Detailed Investigation of Congestion and Economic Benefit Assessment .. 250 IID 230 kV S-Line congestion and capacity benefits .. 251 2017 -2018 ISO Transmission Plan March 22, 2018 California ISO/MID iv Bob SS - Mead S 230 kV line congestion benefits .. 254 San Diego North congestion benefits .. 256 South Bay-Moss Landing Sub-area Local Capacity Requirements .. 259 Summary and Recommendations .. 264 Chapter 5 .. 265 5 Other Studies and Results .. 265 Reliability Requirement for Resource Adequacy .. 265 Local Capacity Requirements .. 265 Resource adequacy import capability .. 268 Long-Term Congestion Revenue Rights Simultaneous Feasibility Test Studies .. 270 Objective.

7 270 Data Preparation and Assumptions .. 270 Study Process, Data and Results Maintenance .. 271 Conclusions .. 271 Chapter 6 .. 273 6 Special Reliability Studies and Results .. 273 Interregional Transmission Project (ITP) Evaluation and 50% RPS Out-of-State Portfolio Assessment .. 274 Objectives .. 276 Study components and methodology .. 279 Key insights .. 280 Recommendations and Next Steps .. 283 Risks of early economic retirement of gas fleet .. 284 Background .. 284 Objectives of Further Study .. 285 Summary of Results .. 285 Benefits Analysis of Large Energy Storage .. 287 Background .. 287 Objectives of Further Study in 2017 .. 291 Summary of System Benefit Results .. 292 Locational benefits .. 294 Frequency Response Assessment Generation Modeling .. 295 Frequency Response and Over generation issues .. 295 New NERC Standards MOD-032 and MOD-033 Modeling Requirements .. 300 Generator Modeling Issues observed in past ISO studies.

8 301 Generator Modeling Upgrades and Validation Study 2016- 2017 .. 304 2016- 2017 Progress .. 304 2017 -2018 Progress and Concerns: .. 306 Gas/Electric Coordination Special Study .. 311 Gas/Electric Coordination Transmission Planning Studies for Southern California .. 311 2017 -2018 ISO Transmission Plan March 22, 2018 California ISO/MID v Northern California Gas-Electric Coordination .. 313 Characteristics of Slow Response Local Capacity Resources .. 315 Background .. 315 How Slow Response Resources can help meet Local Capacity Needs .. 316 Demand response participation in the ISO market and operations .. 318 Study Methodology and Assumptions .. 320 Chapter 7 .. 325 7 Transmission Project 325 Transmission Project Updates .. 325 Transmission Projects found to be needed in the 2017 -2018 Planning Cycle .. 334 Reliance on Preferred Resources .. 336 Additional achievable energy efficiency (AAEE) and Behind-the-Meter PV Generation.

9 336 Integrating Transmission Planning with Preferred Resource Procurement .. 336 Competitive Solicitation for New Transmission Elements .. 338 Capital Program Impacts on Transmission High Voltage Access Charge .. 339 Background .. 339 Input Assumptions and Analysis .. 340 2017 -2018 ISO Transmission Plan March 22, 2018 California ISO/MID vi Intentionally left blank 2017 -2018 ISO Transmission Plan March 22, 2018 California ISO/MID 1 Executive Summary The California Independent System Operator Corporation s 2017 -2018 Transmission Plan provides a comprehensive evaluation of the ISO transmission grid to address grid reliability requirements, identify upgrades needed to successfully meet California s policy goals, and explore projects that can bring economic benefits to consumers. This plan is updated annually, and culminates in an ISO Board of Governors (Board) approved transmission plan that identifies the needed transmission solutions and authorizes cost recovery through ISO transmission rates, subject to regulatory approval, as well as identifying non-transmission solutions that will be pursued in other venues as an alternative to building additional transmission facilities.

10 It is prepared in the larger context of supporting important energy and environmental policies while maintaining reliability through a resilient electric system. The transmission plan is developed through a comprehensive stakeholder process and also relies heavily on coordination with key energy state agencies the California Public Utilities Commission (CPUC) and the California Energy Commission (CEC) for key inputs and assumptions regarding electricity demand side forecast assumptions as well as supply side potential. The aggressive pace of the electric power industry transformation in California continues to set the context for the ISO s annual transmission plan, where the focus is recalibrated each year to reflect the status of a range of issues at that time. This year s transmission plan continues to reflect those changing circumstances and the specific needs emerging at this particular point in time.