3. The Proposed Project
SCE states that the amount of electricity that can presently be delivered into the ENA by the Chino, Soquel, Archibald, and Mira Loma Substations is limited to the maximum amount of electricity that these four substations can transmit before exceeding designed operating limits. The combined electrical capacity of these substations is presently limited to 275 megavolt-ampere (MVA). SCE added capacity to the Archibald Substation in 2007, which will increase the combined operating capacity of these four substations to 311 MVA. SCE states that general plans and specific plans affecting the ENA indicate that by 2025 there will be approximately 16,000 acres of new residential development consisting of 59,800 new units, 900 acres of new commercial development, and 1,160 acres of new light industrial development. This represents approximately 490 MVA of demand at full build-out by 2025 within the ENA.
Although SCE presently plans to upgrade Mira Loma Substation in 2010 to increase capacity in the ENA, these modifications do not eliminate the need for the Proposed Project because the distribution circuits from Mira Loma Substation as well as from Chino, Soquel, and Archibald Substations to certain areas within the ENA are too long to reliably serve demand. SCE states that areas within the ENA are presently experiencing low voltage conditions caused by long distribution lines. SCE has various plans in place to correct the low voltage conditions but asserts that as the source of electrical demand continues to grow and move further from existing substations, it will be more difficult to maintain Commission-mandated voltage levels.
The distribution lines that serve the ENA originate from Archibald, Chino, Soquel, and Mira Loma Substations. Some of these distributions lines range in length from five to seven miles, which were once sufficient to serve electrical demand in the area when the land was primarily used for agriculture. However, a transition from agricultural communities to residential development in the ENA is affecting SCE's ability to serve growing electrical demand using these long distribution lines.
SCE states that the length of the distribution lines from the source substations to portions of the ENA need to be shorter than the existing five to seven mile long distribution lines in order to accommodate the greater demand. The shorter distribution line length is necessary to maintain adequate voltage levels at the end of the line and permits electric system operational flexibility. The shorter distribution line lengths allow SCE to transfer load between distribution lines and between substations in response to variations in demand, thereby reducing the possibility of overloading the equipment and its subsequent failure.
When completed, the Proposed Project will ensure that safe and reliable electric service is provided to meet customer electrical demand without overloading the existing electric facilities that supply the ENA by (1) increasing the total transformation capacity available within the ENA, (2) providing enhanced system reliability by locating Kimball Substation in proximity to area of load growth, (3) enhancing operational flexibility by providing the ability to transfer load between distribution lines and substations within the ENA, and (4) meeting projected demand in the ENA.
The Proposed Project includes the following:
1. Construction of a new 66/12 kV substation (Kimball Substation). The proposed Kimball Substation will be constructed on an approximately 2 acre site in the City of Chino, and will be an unmanned, automated, low-profile, 56 MVA 66/12 kV substation.
2. Modification of approximately 6.7 miles of the Chino-Corona-Pedley 66 kV subtransmission line and the construction two new 340-foot long underground circuits to extend the Chino-Corona-Pedley line into the proposed substation. The existing lines to be modified are located in either SCE-owned rights-of-way or public street rights-of-way. Along approximately 5.6 miles of the line, the existing wood poles will be replaced with LWS poles and the conductor will be replaced. Along approximately 1.1 mile of the line, the conductor will be replaced on poles that will have been replaced before construction of the Proposed Project as part of a separate relocation project exempt from General Order (GO) 131-D. These modifications will form the new Chino-Kimball 66 kV subtransmission line.
3. Addition of a second circuit to an approximately 0.9 mile segment of the existing Archibald-Chino-Corona 66 kV subtransmission line and construction of a new 0.4 mile segment within public street rights-of-way to connect the Chino-Corona-Pedley 66 kV line to the Archibald-Chino-Corona 66 kV line. These modifications will form the new Chino-Cimgen-Kimball 66 kV subtransmission line.
4. Construction of six 12 kV underground circuits extending from the proposed substation to the nearest public street.
5. Installation of new fiber optic cable and communication equipment to connect the proposed Kimball Substation to SCE's existing telecommunication system.
The estimated cost of the project is $13.3 million.3 The original one-year construction period was scheduled to begin in July 2008 and the originally planned operating date for the Proposed Project was June 2009. However, this schedule was subsequently revised. Construction is now scheduled to begin in September 2009 and SCE plans to begin operating the Proposed Project in June 2010.
3 PEA, at 2-2.
