Memorandum. This memorandum requires Committee action.

Transcription

1 California Independent System Operator Corporation Memorandum To: ISO Operations Committee From: Dariush Shirmohammadi, Director of Regional Transmission - South Armando Perez, VP, Planning & Infrastructure Development Date: June 7, 2006 Re: Approval of City of Riverside 230kV Transmission Interconnection Project This memorandum requires Committee action. EXECUTIVE SUMMARY This memorandum is a request for the ISO Operations Committee to recommend the Board s approval of the City of Riverside 230 kv Transmission Interconnection Project described as Option 1 in this memorandum. This project, which is needed as soon as possible to reliably serve load growth in the City of Riverside, includes a loop in the Mira Loma-Vista #1 230 kv transmission line and construction of a new 230/66 kv Substation. The estimated cost of the project is $ 52.5 million in 2008 dollars - $ 48.2 million for ISO controlled facilities and $ 4.3 million for non-iso controlled facilities. MOVED, that the Operations Committee recommends that the Board of Governors grant its approval of: the City of Riverside Transmission Project (Option 1 as described in this Memorandum dated June 7, 2006) as a necessary and cost effective addition to the ISO Controlled Grid and Directs Southern California Edison (SCE) to complete the construction of the City of Riverside Transmission Project as soon as possible and preferably no later than Q2, 2008; and support of SCE recovery of reasonably incurred costs associated with the permitting and construction of the City of Riverside Transmission Project (Option 1 as described in this Memorandum dated June 7, 2006) in relevant FERC and CPUC rate cases. ISSUE STATEMENT An interconnection study request was made by the Riverside Public Utilities (RPU) for the City of Riverside after Southern California Edison (SCE) had indicated that the existing 230/66 kv point of interconnection between SCE and Riverside at SCE s Vista Substation will not be adequate to serve Riverside s increased load in the future. The 2005 actual peak load 151 Blue Ravine Road Folsom, California (916)

2 was 552 MW. The projected 2006 peak load of 583 MW (1-in-10 year forecast) will exceed the combined capacity of the two A transformer banks (557 MVA) used to provide service to the City of Riverside. 1 SCE has determined that there are physical size limitations that restrict the expansion of the existing Vista 230 kv switch-rack. Expansion of the 230 kv bus by installation of another 230 kv bus across from the substation connected by 230 kv underground (UG) cables is also not possible due to an existing UG pipeline. Further expansion of the Vista Substation is not viable and it is not desirable to continue with a single point of service for the City of Riverside. A second point of service is required for the City of Riverside. OPTIONS TO SOLVE PROBLEM OR DEAL WITH THE ISSUE Three options were investigated to provide a second point of service to the City of Riverside. Option 1: Loop the existing Mira Loma-Vista #1 230 kv line by building 8.25 miles of new 230 kv double circuit transmission line from the existing Mira Loma-Vista #1 T/L ROW to into a new 230 kv SCE interconnection facility with RPU s new Jurupa Substation in Riverside. Option 2: Build a 230 kv SCE interconnection facility located at Riverside s new Jurupa Substation with two new 230 kv lines from the Mira Loma and Vista substations to the new Jurupa Substation. Option 3: Build a new SCE 230 kv interconnection facility adjacent to the existing Mira Loma Vista 230 kv rightof-way with new 8.25 miles of double circuit 230 kv transmission to a new Riverside 230/66 kv Jurupa Substation. SCE studies concluded that Options 2 was impractical 2 and Option 3 cost higher than Option 1. Option 1 would have no adverse system impacts and no system upgrades are necessary other than those facilities necessary to loop the Mira Loma-Vista #1 230 kv transmission line and the SCE constructed 230 kv substation. The recommended Option 1 is shown in the attached Figure 1. Also shown are the ISO and non-iso controlled facilities. RPU proposes to serve about half of its retail load radially from Vista Substation and the other half from the new Jurupa 230/66 kv substation 283 MW of the year 2008 load will be transferred from six existing 66/12 kv substations currently being supplied from the 230/66 kv Vista Substation. The new 230/66 kv Jurupa Substation is planned to serve up to 560 MW of existing and future load. RPU may not parallel the facilities served by the Jurupa Substation with any other electrical facilities served by SCE or others without receiving review and authorization. POSITIONS OF THE PARTIES Both RPU and SCE support the project and have formally requested ISO Board approval. SCE plans to finance, construct, own and maintain the new transmission facilities of the project upon Board approval and receipt of other necessary regulatory approvals. SCE intends that the $ 48.2 million cost of the ISO-controlled facilities constructed and 1 The capability of the existing supply from Vista may be exceeded this summer. To overcome this Riverside has two internal generating plants, with a combined nominal rating of 140 MW. This generation will be used to maintain the Vista transformer loading within acceptable limits, until the Jurupa Project can be constructed. 2 Option 2 is not feasible due to physical limitation at the Vista 230 kv bus.! Page 2

3 owned by SCE will be recovered through the ISO transmission access charge. SCE would recover the $ 4.3 million for non-caiso facilities from the City of Riverside (RPU) through their Wholesale Distribution Access Tariff (WDAT). Both SCE and City of Riverside (RPU) are Participating Transmission Owners pursuant to the ISO Tariff. RPU and SCE have entered into an Interim Agreement in order to expedite certain pre-construction activities while an Interconnection Agreement is developed that contains terms for RPU to interconnect to the SCE electrical system and for SCE to construct, own, operate and maintain the 230 kv lines and 230 kv substation developed pursuant to SCE s TO tariff. RPU will construct, own, operate and maintain the 66 kv switchyard facilities with 2-230/66 kv, 280 MVA transformers. MANAGEMENT RECOMMENDATION Based on the assessments performed, ISO Management recommends approval of the City of Riverside Transmission Interconnection Project. The City of Riverside may not parallel the facilities served by the Jurupa Substation with any other electrical facilities served by SCE or others without receiving review and authorization. MOVED, that the Operations Committee recommends that the Board of Governors grant its approval of: the City of Riverside Transmission Project (Option 1 as described in this Memorandum dated June 7, 2006) as a necessary and cost effective addition to the ISO Controlled Grid and directs Southern California Edison Company (SCE) to complete the construction of the City of Riverside Transmission Project as soon as possible and preferably no later than Q2, 2008; and support of SCE recovery of reasonably incurred costs associated with the permitting and construction of the City of Riverside Transmission Project (Option 1 as described in this Memorandum dated June 7, 2006) in relevant FERC and CPUC rate cases.! Page 3

4 Figure 1 Recommended Option 1 for City of Riverside 230 kv Transmission Interconnection Project To Mira Loma Substation Existing Mira Loma Vista Line #1 230 kv T/L To Vista Substation New 8.25 miles of 230 kv double-circuit transmission line 230 kv Highlight indicates Non-ISO Controlled Facilities New Jurupa Substation SCE Riverside WW WW kv, 280 MVA Transformer To City of Riverside! Page 4

5 ! Page 5 Figure 2 Proposed for City of Riverside 230 kv Transmission Interconnection Project