Preliminary Planning Study Central California Clean Energy Transmission Project Study Plan Version 1.2 February 29, 2008 Stakeholder Group Study 1 Table of Contents Study Objective...................................................................................................................3 Potential Alternatives ..........................................................................................................3 Alt-1: Status Quo.............................................................................................................3 Alt-2: Central California Clean Transmission Project (C3ETP).....................................3 Alt-3: Same as Alt-2, except building a Midway – E2 Single Circuit Tower Line (SCTL) ............................................................................................................................5 Alt-4: Build a Whirlwind – San Joaquin - E2 500 kV DCTL.........................................5 Alt-5: Build a Midway – E2 230 kV DCTL...................................................................5 Alt-6: Build a new PG&E and SCE Big Creek 230 kV Tie............................................6 Alt-7: Build a Midway – McCall – E2 230 kV DCTL....................................................6 Alt-8: Build a Gates – Gregg 230 kV DCTL ..................................................................6 Alt-9: Raisin City Switching Station...............................................................................7 Alt-10: New Generation..................................................................................................7 Reliability Assessments.......................................................................................................8 1. Study Base Cases: ...................................................................................................8 2. Renewable Resources............................................................................................10 3. 500 and 230 kV Contingencies .............................................................................10 4. Sensitivity Studies:................................................................................................10 5. Study Criteria........................................................................................................11 6. Study Scope...........................................................................................................11 7. Methodology for Reliability Analysis...................................................................11 a. Load Serving Capability to the Fresno and Yosemite Area..................................11 b. Transmission Capacity for Supporting Helms Pumping Operation......................12 c. Import Capability from southern California..........................................................12 Economic Assessments .....................................................................................................13 1. Methodology for Economic Analysis ...................................................................13 2. Study Base Cases for Economic Analysis.............................................................14 Preliminary Study Schedule..............................................................................................16 Attachment 1 One Line Diagram ......................................................................................17 Attachment 2 Transmission Facilities Included in Reliability Assessment Base Cases ...31 Attachment 3 Potential New Generation in the Greater Fresno Area ...............................35 Attachment 4 Renewable Resource List Modeled in 2022 Summer Peak Base Case).....37 Attachment 5 List of Old Thermal Generation Plants (May be Modeled Off-line)..........40 Attachment 6 List of Contingencies..................................................................................44 Attachment 7 Reliability Criteria ......................................................................................47 2 Study Objective The purpose of this study is to evaluate further the benefits of potential alternatives that could meet the following major long-term (at least 20 years) goals in order to identify the least cost-highest benefit alternative that achieves these goals: 1. Support California’s Renewable Portfolio Standard (RPS) target(s) by increasing the ability of Central and Northern California to access renewable resources in southern California; 2. Improve transmission reliability and serve load growth in the Fresno and Yosemite areas by allowing sufficient access to generation to meet local demand for at least the next twenty (20) years; 3. Maximize asset utilization by providing support for all three units at Helms Pumped Storage Plant (PSP) to operate in the pumping mode using excess off- peak energy; 4. Provide opportunity for future expansion that can be integrated with the California regional bulk transmission system, in order to allow increased access to renewable resources and other resources, including greenhouse-gas neutral resources, in Southern California in order to serve load growth in the San Francisco Bay Area, Sacramento Valley Area, and other areas. Potential Alternatives Alt-1: Status Quo Alt-2: Central California Clean Transmission Project (C3ETP) The Central California Clean Transmission Project (C3ETP) would build a new 500 kV Double Circuit Tower Line (DCTL) from Midway to a new 500/230 kV Substation (E2) between Gregg substation and Helms PSP. See Fig 1. This project includes the following facilities: 1. Build a 500 kV DCTL strung with two 2300 kcmil AAL conductors (bundled), 2. Build a new 500 kV Substation (E2) with one 500/230 kV 1,120 MVA transformer bank, 3. Loop the Helms – Gregg #1 and #2 230 kV lines into the E2 Substation, 4. Build 500 kV line terminations at Midway and E2, and 5. Install additional voltage supports in the Fresno area. The amount and location of the voltage support will be evaluated in a separate voltage stability study. This alternative will mainly consider two alternative corridors; an east corridor and a west corridor. East Corridor: The potential route on the east corridor (or east route, which is estimated to be about 141 miles) is easterly of the Southern California Edison’s Big Creek 230 kV corridor and 3 terminates at the new E2 Substation at where it crosses of the Helms-Gregg 230 kV lines. Because it would run parallel to SCE’s Big Creek – Magunden 230 kV lines for part of the distance, the east route of the C3ET Project could potentially use SCE’s existing access roads and could also support SCE’s future expansion plans to serve SCE’s customers in the Big Creek area. SCE’s future expansions alternatives, which could take advantage of the east route should the associated CPCN be granted are as follows: Alt-2A: Build a San Joaquin 500 kV Substation looping into one of the Midway – E2 500 kV DCTL Alt-2A is a future expansion alternative of the C3ET Project. This alternative would allow SCE to build the following facilities to serve SCE’s customers in the Big Creek area: 1. A new SCE 500/230 kV Substation (currently named “S2”) with two 500/230-kV 1,120 MVA transformer banks in the vicinity of the SCE’s San Joaquin Valley load center 2. Loop one Midway-E2 500-kV line into S2 Substation 3. Loop three existing Big Creek Corridor 230-kV transmission lines into the new S2 Substation (i.e., Big Creek 4-Springville 230-kV, Big Creek 3-Rector No. 2 230-kV, and Rector-Springville 230-kV) Alt-2B: Same as Alt-2A, except also building a Magunden 500 kV Substation looping into the second Midway – E2 500 kV DCTL and a new Magunden – Whirlwind 500 kV SCTL Alt-2B is also a future expansion alternative of the C3ET Project. This alternative is same as Alt-2A, except it would allow SCE to build the following additional facilities to serve SCE’s customers in the Big Creek area: 1. Build a new SCE 500/230-kV Substation (S3 or “Magunden 500-kV”) with one 500/230-kV 1,120 MVA transformer bank in the general vicinity of the existing SCE Magunden 230-kV Substation, 2. Loop the second Midway – E2 500 kV line into S3 Substation by building a 500 kV DCTL from the C3ET Project to S3 Substation, 3. Construct a Whirlwind- S3 500 kV SCTL 4. Connect the S3 substation 230-kV bus to the existing Magunden 230-kV bus via short segment of 230-kV DCTL (“jumper”) Alt-2C: Same as Alt-2A, except also upgrade PG&E-own section of the Midway – Vincent #3 500 kV line Alt-2C is also a future expansion alternative of the C3ET Project. This alternative would include upgrading by PG&E of the northern section of the Midway – Vincent #3 500 kV line (owned by PG&E) to improve transfer capability on Path 26 in both directions; Importing additional renewable resources from southern California and increasing power transfer to southern California. 4 West Corridor: The west corridor of the C3ET project runs west of the existing Los Banos – Midway 500 kV line corridor, then crosses the valley at a point north of Avenal to the vicinity of Gregg Substation (about 147 miles) and then extends to and terminates at the new E2 Substation (an additional 30 miles). As such, a route in the west corridor (west route) would be too far away from the SCE’s Big Creek area to support any SCE’s future expansion alternatives described above to serve customers in the Big Creek area. Alt-3: Same as Alt-2A, except building a Midway – E2 Single Circuit Tower Line (SCTL) This alternative will build a Midway – E2 500 kV SCTL with 50% series compensation. Alt-4: Build a Whirlwind