2018 General Rate Case. Transmission & Distribution (T&D) Volume 3 R System Planning

Transcription

1 Application No.: Exhibit No.: Witnesses: A.1-0- SCE-0, Vol. 0 R E. Takayesu A (U -E) 01 General Rate Case Transmission & Distribution (T&D) Volume R System Planning Before the nd Errata Public Utilities Commission of the State of California Rosemead, California September, 01

2 1 DER solutions will meet the current need associated with one or more of the projects, SCE will refund the balance to customers. However, should the projects be determined to be needed at or sooner than expected due to increased load growth not met by DERs, then SCE will have recovered the revenue requirements associated with these expenditures as part of this request. IV. $,1 $,1 CAPITAL EXPENDITURE FORECASTS SCE is forecast to spend $, million in total capital expenditures from 01 00, of which $,1 million is CPUC-jurisdictional. Table IV- shows the total company (FERC and CPUCjurisdictional) capital expenditure summary and Table IV- shows the CPUC-jurisdictional capital expenditures only. SCE s System Planning work is managed through four primary categories: =, 01=,0 01=, 01=,0 00=, Total=1,1 1. Transmission & Interconnection Planning Projects, described in Section A;. Distribution & Subtransmission Planning Programs and Projects, described in Section B;. System Improvement Programs, described in Section C; and. Customer-Requested Projects, described in Section D. Table IV- System Planning Capital Expenditure Summary 01 (Total Company Nominal $000) 01=,01 01=, 01=1,0, 01=, 00=0, Total=,1,1 Note that the cost recovery for the DERs will not be collected through the GRC. 0 Refer to WP SCE-0 T&D-Vol., Book A, pp. (Tables IV- and IV-). 1 The following capital expenditures for projects with operating dates prior to 01 are not included in the table above: $1. M in 01, $.M in 01, and $.M in 01. Refer to WP SCE-0 T&D-Vol., Book A, pp. (In-Service Projects with CapEx in this GRC). -0-

3 01=, 01=,0 01=, 01=,0 00=, Total=1,1 Table IV- System Planning Capital Expenditure Summary (CPUC-Jurisdictional Nominal $000) 01=,1 01=, 01=,1 A. Transmission & Interconnection Planning Projects 01=, As described in the Transmission & Interconnection Planning Process Section III.A, SCE s 00=0,01 Total=,1,0 Transmission & Interconnection Planning Projects fall into three categories: (1) Grid Reliability Projects needed to support grid reliability; () Transmission System Generation Interconnection Projects needed to interconnect individual generation customers; and () Policy-driven Projects must support state and federal policy to deliver energy to SCE s transmission system. While the majority of work for these transmission projects fall under FERC-jurisdiction, some of these projects include components under CPUC jurisdiction such as upgrades to the underlying subtransmission system or equipment supporting telecommunications, automation, and controls. Both the total project and CPUC-jurisdictional forecast expenditures for these three project categories are shown in Table IV- and Table IV- respectively. The total company cost for all three categories of transmission work is $1,0. million. The CPUC-jurisdictional cost for these projects is $01. million. The tables also include the Generation Interconnection RAS, which has no forecast CPUC-jurisdictional capital expenditures and will not be discussed further in this testimony. Id. See SCE-0, Vol. 1 for SCE s methodology for separating capital expenditures between FERC and CPUC jurisdiction. -1-

4 SCE in 01, the analysis performed in reviewing how DERs impact the distribution system found that clustered DERs will drive more upgrades. 0 The study assumed. percent 1 of the allocated DERs were generating during minimum loading for each distribution circuit, versus 0 percent as often considered for impact studies. By comparing the forecast power flow to the rated capacity of the circuit conductors, the study identified approximately 1 circuit-miles of cable and conductor requiring replacement from on SCE s kv, 1 kv, and 1 kv distribution circuits. Of the circuit-miles, 1 circuit-miles will be overhead conductor and 1 circuit-miles will be underground cable. The total estimated cost to replace miles of overhead conductor and underground cable due to DER exceeding loading limits is approximately $. million (nominal dollars) from The forecast expenditures driven by load growth represent our baseline forecast for distribution circuit upgrades for The expenditure was reduced by $. million to account for energy storage pilots planned to meet distribution needs. 1 Last, forecast expenditure for DER driven upgrades are added to the cost for These three aspects were combined to develop the final expenditure for this category. We forecast capital expenditures to increase by approximately $.0 million per year (in constant 01 dollars) from compared to historical expenditures; as referenced before, 0 expenditure was omitted from the comparison due to changes in accounting. From SCE expects to slowly increase spending in this category to better utilize existing distribution asset capacity and address needs on the kv system.. New Distribution Circuits, WBS Element CET-ET-LG-CI As part of our DSP Program, SCE identifies new distribution circuits as part of three types of projects: new substation projects, substation capacity increase projects, and projects with unique drivers. Figure IV-1 shows the historical 0 costs for these three categories of new distribution circuits while future expenditure only includes standalone circuit projects. This is due to recent accounting changes to avoid overlap in capital expenditure requests. New distribution circuits are required to provide new capacity outside the substation fence in areas where multiple distribution circuits in the same geographical region are expected to exceed capacity; to serve new residential or 0 The Impact of Localized Energy Resources on SCE s Distribution and Transmission System, SCE, May Refer to WP SCE-0 T&D-Vol., Book A, pp. 1 (DER Driven Circuit Upgrades Methodology). Id. Refer to WP SCE-0 T&D-Vol., pp. (Cost of Overhead Conductor Rebuilds). 1 See SCE-0 T&D-Vol. Distributed Energy Storage Integration (DESI) Pilot Program. --

5 approximately a quarter mile from the Mono Lake Fault line and has antiquated equipment that is vulnerable to significant earthquakes. The scope of the project includes a complete rebuild of the substation to current reliability and seismic standards. This includes rebuilding the kv and kv switchracks, replacing the. kv switchrack with a 1 kv switchrack, installing two MVA / kv transformers, and installing two MVA /1 kv transformers. Upon completion of rebuilding Lee Vining Substation, the Cain Ranch./1 kv substation will be decommissioned and the existing. kv circuit currently served from Lee Vining Substation will require a new 1/. kv pole top. This will allow SCE to continue serving customers from the same. kv distribution circuit. The operating date is June 01 with a total project cost of $. million. SCE has identified one alternative for this project. The alternative is to eliminate the kv facilities at Lee Vining / kv substation which requires upgrades to subtransmission lines and neighboring Lundy /1 kv substation. The scope of work at Lee Vining / kv substation includes converting the substation from //. kv to a /1 kv substation, rebuilding the kv switchrack, installing two MVA /1 kv transformers, replacing the low voltage switchrack from. kv to 1 kv, and reconfigure distribution circuitry. The scope of work at Lundy /1 kv substation includes replacing the existing kv switchrack with a kv switchrack, install two MVA /1 kv transformers, and install one MVA /. kv transformer to interconnect existing hydroelectric generation. The subtransmission line work includes replacing approximately. miles of conductor and poles converting both Lee Vining-Lundy No.1 and Lee Vining-Lundy No. from kv to kv and tie in a new subtransmission line to feed temporary / kv transformation while the Lee Vining / kv substation rebuild construction is completed. The total estimated cost for the alternative is $1. million. The preferred project was selected because it is the most cost effective solution.. kv Programs The kv Programs include the conversion or elimination of substations and circuits to address equipment obsolescence, overloads, and reliability. Table IV-1 below shows the total capital forecast for kv Programs. --

6 (1) Santa Barbara County Reliability Project (Project #01) The Goleta-Santa Clara No. 1 and No. 0 kv transmission lines serve Goleta 0/ kv Substation, which serves approximately,000 metered customers in the city of Santa Barbara and surrounding communities. The Goleta-Santa Clara No. 1 and No. 0 kv Transmission Lines are approximately miles long, run on a common steel tower over hilly terrain subject to mudslides during rainy conditions, and are the sole source to Goleta 0/ kv Substation. During the preparation for El Nino in 01, this system received considerable attention from the community and third parties concerned about the potential reliability issues raised if a major landslide occurs that could jeopardize the integrity of the transmission lines, threatening the reliability of service to the Santa $. (DR CUE-DR- Barbara area. Q1) The project scope is to rebuild approximately. miles of existing /0 copper conductor kv subtransmission line connecting the Goleta kv System and the Santa Clara kv System with higher capacity rated Aluminum Conductor Steel Reinforced conductor. Rebuilding this kv subtransmission line will allow approximately two-thirds of the load served by Goleta 0/ kv Substation to be safely and reliably transferred to the neighboring Santa Clara 0/ kv Substation during an outage of the Goleta-Santa Clara No. 1 and No. 0 kv Transmission Lines. The operating date is December 01 with a total project cost of $1. million. This project was included in SCE s 01 GRC filing with a June 01 operating date and in the 01 GRC with a June 01 operating date, but was subsequently moved to December 01 due to the CPUC requiring that the project go through licensing. The CPUC issued SCE a Permit to Construct in Decision D (D.1--00) on November, 01. SCE identified one alternative to this project to construct a new 0 mile 0 kv transmission line from Santa Clara 0/ kv Substation to Goleta 0/ kv Substation. The alternative analysis can be found in the PEA (Application A filed October, 01). The total estimated cost of this alternative is $. million. SCE s proposed project is expected to cost $. million and was selected as the lower-cost alternative. () Base Case Reconductor/Recable Projects Of the remaining 1 subtransmission line reconductor/recable projects, six are needed to correct forecast normal base case overloads. These include the Vestal-Mariposa kv Line, the Vestal-Columbine-Delano-Earlimart kv Line, and the La Cienega Beverly Culver kv Line which correct both Base Case and Likely Contingency violations. In addition, normal Base --

7 Table IV-0 Subtransmission VAR Plan Capital Expenditure Summary (CPUC-Jurisdictional Nominal $000) Line Project Operating Project Name No. No. Date Prior Total 1 0 Projects with CPUC-jurisdictional cost < $M 1,00 1,0 1,0 1,0 1,, Total Subtransmission VAR Plan 1,00 1,0 1,0 1,0 1,, 1 C. System Improvement Programs The System Improvement Programs include three categories in which expenditure forecasts are developed: 1) Substation Equipment Replacement Program, ) Distribution VAR Plan, and ) the Substation Monitoring Program. These programs include evaluation and identification of equipment near or at the limit of its protection level, supplying sufficient reactive power to the distribution electrical system, and installing monitoring systems at substations to enable the retrieval of substation 01=1,1 loading and underground cable temperature data. SCE explains how these System Improvement 01=0, 01=,0 Programs are planned in Section III.C. Brief descriptions of these categories and forecasts are included 01=, below. 00=1,1 Total=1, Table IV-1 System Improvement Programs Capital Expenditure Summary (CPUC-Jurisdictional Nominal $000) 1. Substation Equipment Replacement Program, WBS Element CET-ET-LG-SU The Substation Equipment Replacement Program (SERP) covers forecast expenditures 01=, 01=,0 1 for work required to replace substation equipment identified to exceed their protection ratings to 01=, 1 interrupt fault current. SCE has identified substation circuit breakers projected to exceed short circuit 01=,0 00=, duty interrupting capabilities. Circuit breakers attempting to interrupt fault current that exceed ratings Total=1,1 1 have the potential to cause catastrophic failure resulting in prolonged outages. Leaving these breakers in 1 1 Line No. Program/Project Category Total 1 Substation Equipment Replacement Program 1, 1, 0, 1,0, 1, Distribution VAR Plan,,1,,1,1, Substation Monitoring Programs Total System Improvement,1,,1,0 0,0 1,1 service jeopardizes worker safety proposing the potential scenario where a catastrophic failure occurs when work is being performed in the substation. The only alternative option to replacing circuit breakers Refer to WP SCE-0 T&D-Vol., Book A, pp. 0 (Table IV-1). --

8 1 is to split the substation bus. This can reduce short circuit duty at circuit breakers at the bus being split. However, this solution can only be accomplished at subtransmission substations and not available for distribution substations. Splitting the bus at a distribution substation incorporates risk of not providing enough fault current to operate circuit breakers. In addition, the option of splitting a subtransmission substation bus is usually not a cost effective solution compared to replacing circuit breakers. More details on how SCE plans for this category is explained in Section III.C.1. SCE analyzed historical cost data to develop unit costs for circuit breaker replacements in this category. The unit cost was applied to our forecast units to develop our annual expenditure forecast. Table IV- provides the unit cost, unit count, and annual expenditure forecast for circuit breaker replacements in each voltage class for the SERP category. Table IV- Substation Equipment Replacement Program Capital Expenditure Forecast 1 WBS Element CET-ET-LG-SU (CPUC-Jurisdictional Nominal $000) kv CBs to Replace 1 kv Unit Cost $ $ $ $ $0 Subtotal $, $, $1,1 $1, $, kv CBs to Replace 1 1 kv CBs to Replace kv CBs to Replace kv Unit Cost $1 $1 $1 $1 $1 1 kv Unit Cost $1 $1 $1 $1 $1 1 kv Unit Cost $1 $1 $1 $1 $1 Subtotal $,0 $1, $1,0 $1, $1, Total $1, $1, $0, $1,0 $, 1 1 Figure IV- below, shows 0 01 recorded and forecast expenditures for SERP. From 0 01, our SERP expenditures averaged $. million per year (in constant 01 dollars). The total cost for the SERP over the forecast period is $1. million (in nominal dollars), or an average of $. million per year (in constant 01 dollars) in the period. Refer to WP SCE-0 T&D-Vol., pp. 1 1 (Cost of Circuit Breaker Replacements). 1 Refer to WP SCE-0 T&D-Vol., Book A, pp. 0 (Table IV-1). --

9 1 is to split the substation bus. This can reduce short circuit duty at circuit breakers at the bus being split. However, this solution can only be accomplished at subtransmission substations and not available for distribution substations. Splitting the bus at a distribution substation incorporates risk of not providing enough fault current to operate circuit breakers. In addition, the option of splitting a subtransmission substation bus is usually not a cost effective solution compared to replacing circuit breakers. More details on how SCE plans for this category is explained in Section III.C.1. SCE analyzed historical cost data to develop unit costs for circuit breaker replacements in this category. The unit cost was applied to our forecast units to develop our annual expenditure forecast. Table IV- provides the unit cost, unit count, and annual expenditure forecast for circuit breaker replacements in each voltage class for the SERP category. Table IV- Substation Equipment Replacement Program Capital Expenditure Forecast 1 WBS Element CET-ET-LG-SU (CPUC-Jurisdictional Nominal $000) kv CBs to Replace 1 kv Unit Cost $ $ $ $ $0 Subtotal $, $,0 $,01 $1, $1, kv CBs to Replace 1 1 kv CBs to Replace kv CBs to Replace kv Unit Cost $1 $1 $1 $1 $1 1 kv Unit Cost $1 $1 $ $ $1 1 kv Unit Cost $1 $1 $ $ $1 Subtotal $,0 $1, $1,0 $1,1 $1, Total $1,1 $0, $,0 $, $1,1 Figure IV- below, shows 0 01 recorded and forecast expenditures 1 for SERP. From 0 01, our SERP expenditures averaged $. million per year (in constant 01 1 dollars). The total cost for the SERP over the forecast period is $1. million (in nominal dollars), or an average of $. million per year (in constant 01 dollars) in the period. Refer to WP SCE-0 T&D-Vol., pp. 1 1 (Cost of Circuit Breaker Replacements). 1 Refer to WP SCE-0 T&D-Vol., Book A, pp. 0 (Table IV-1). -- A

10 Nominal 01=1,1 01=0, 01=,0 01=, 00=1,1 Figure IV- Substation Equipment Replacement Program (SERP) Expenditures WBS Element CET-ET-LG-SU Recorded 0-01/Forecast (CPUC-Jurisdictional Constant 01 and Nominal $000) Constant 01$ 01=1,0 01=1, 01=,0 01=, 00=, In 01, SCE analyzed the short circuit duties at existing substations against the ratings of the circuit breakers. This analysis prioritized circuit breaker replacements based on percentage of overstress to mitigate safety risks. The result was the development of a plan to address projected overstressed distribution breakers and 1 overstressed subtransmission breakers in years The forecast expenditures are displayed in Figure IV-. The evolving state of both the transmission and distribution systems has resulted in increased Short Circuit Duty levels across the SCE system. SCE views this as an issue important to system safety and reliability and accommodating DERs. 1 SCE is increasing the total distribution and subtransmission level breaker replacements compared to historical replacements to help facilitate DER expansion and maintain safety and reliability of the electrical system as it evolves.. Distribution VAR Plan, WBS Element CET-PD-LG-NC Distribution capacitor banks supply reactive power (VAR) to the distribution system to maintain acceptable power factor and suitable voltage to serve customers. Reactive power demand increases as load continues to increase on the system. Distribution capacitors are connected along the 1 Refer to WP SCE-0 T&D-Vol., Book A, pp. 1 (DER Driven Circuit Upgrades Methodology). --