Sycamore to Penasquitos 230 kV Transmission Line Project


Customers frequently hear from government officials, utilities, and the media that the “utility industry is changing.” The California Independent System Operator’s (CAISO) competitive solicitation for the proposed Sycamore to Peñasquitos 230 kV transmission line is an example of these changes. CAISO conducts a yearly Transmission Planning Process where it collaborates with Participating Transmission Owners to study the reliability of the state’s electric system.

The 2012-2013 Transmission Plan identified the proposed project as reliability-driven but eligible for competitive solicitation because of policy benefits such as meeting state environmental and energy policy goals. On June 3, 2013, SDG&E submitted a comprehensive bid to CAISO for the proposed project. This is the first transmission project within SDG&E’s service area that required a competitive bid from SDG&E.  On March 4, 2014, CAISO announced that it had selected SDG&E as the winning Project Sponsor responsible to finance, construct, own, operate and maintain the new line.  

Project Purpose and Need

  • Efficiency – Deliver imported energy more efficiently to the San Diego coastal area.
  • Policy – Meet state policy goals addressing the planned retirement of coastal power plants that use once-through cooling systems.
  • Electricity Demand – Reliably and economically meet the forecasted increase in electricity demand in the San Diego region.
  • Task Force – A statewide task force, requested by Governor Brown, deemed the Proposed Project as necessary for grid reliability, due to the planned retirement of coastal power plants as well as the unanticipated early retirement of the San Onofre Nuclear Generating Station.
  • CAISO – The proposed project was approved as part of CAISO’s 2012-2013 Transmission Plan.

Project at a Glance

SDG&E submitted an application to the California Public Utilities Commission (CPUC) for approval to construct a new 230-kilovolt (kV) transmission line that would run approximately 16.7 miles from our existing Sycamore Canyon Substation on Marine Corps Air Station (MCAS) Miramar to our existing Peñasquitos Substation located in the Torrey Hills area.   

The proposed project is broken into the following primary components

  • Segment A – Replace existing 138 kV wood frame structures with new 230 kV steel poles. The 8.3 miles are within SDG&E’s existing right-of-way that runs from the Sycamore Canyon Substation and Carmel Valley Road.
  • Segment B - Install a new 230 kV underground transmission line along Carmel Valley Road. The 2.8 miles are located in SDG&E’s existing franchise position.
  • Segment C – Install a new 230 kV conductor on existing 230 kV steel structures. The 2.2 miles are located in SDG&E’s existing right-of-way between Carmel Valley Road and Peñasquitos Junction.
  • Segment D - Install a new 230 kV conductor on existing 230 kV steel lattice towers and relocate two existing 69 kV power lines to new tubular steel poles. The 3.3 miles are within SDG&E’s existing right-of-way located between Peñasquitos Junction and the Peñasquitos Substation.
  • Minor modifications of the existing Sycamore Canyon and Peñasquitos Substations to allow for connection of the new 230 kV transmission line.

Key Benefits

  • Improved reliability and integration of existing renewable energy into our system.
  • Use of existing electric utility corridors, structures, access to roads and work areas.
  • Fire “hardening” by replacing existing wood structures with steel.

Proposed Project Schedule

  • Construction start date: June 2016
  • In-service date: May 2017

Next Steps

On July 24, 2014 the CPUC deemed the SDG&E Certificate of Public Convenience and Necessity (CPCN) Application complete.  It’s anticipated that the CPUC, as the lead agency, will begin the California Environmental Quality Act (CEQA) process in August 2014.  Check back here for updates on project progress.

More Information

Contact SDG&E's Public Affairs Department for more information.

Todd Voorhees
Public Affairs Manager
(866) 382-0886
[email protected]