Sycamore to Peñasquitos 230-kV Transmission Line Project

The California Public Utilities Commission (CPUC) approved a new 230-kilovolt (kV) transmission line that will run between SDG&E’s existing Sycamore Canyon and Peñasquitos substations on October 13, 2016. The new line will help improve reliability and integrate more renewable energy into our system, which helps meet state mandated goals. 

Project Schedule

  • Construction start date: January 2017
  • In-service date: June 2018

Construction Activity

Our work is likely to affect your business operations. Please use this questionnaire to tell us more about your business and any concerns you may have.

Business questionnaire (fillable PDF) 

SDG&E and its contractors will perform:

  • Site preparation
  • Staging yard preparation and mobilization
  • Conductor and structure removal
  • Foundation and structure construction
  • Wire stringing
  • Road excavation and trenching
  • Vault installation, conductor pulling and splicing
  • Clean up and restoration

Helicopters will be used for some activities along Segments A and C. Construction yards will be used for equipment staging, prepping materials and other construction-related activities.

Construction activities often occur intermittently and are not completed concurrently. Traffic control measures will be followed in accordance with the City of San Diego and the Caltrans issued Traffic Control plans and permits.

Construction for each segment will start after the Notice to Proceed is received from the CPUC and all preconstruction conditions have been satisfied.

Project Purpose and Need

A 230-kV transmission line connecting the Sycamore Canyon and Peñasquitos substations is critically needed for a number of reasons.

  • 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.
  • Grid Reliability – A statewide task force, requested by Governor Brown, deemed the 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.
  • Priority – The California Independent System Operator identified this project as a priority in its 2012-2013 Transmission Plan.

Project at a Glance

The project consists of approximately 14 miles traversing through developed residential and commercial areas as well as undeveloped areas and includes the following components: 

Segment A  

  • Construction of approximately .75 miles of new 230-kV transmission line and relocated 138-kV power line located underground and on new steel poles and steel H-frame structures all within SDG&E’s existing right-of-way located between the Sycamore Canyon Substation and a trail starting at Stonebridge Parkway.

Segment B

  • Construction of approximately 11.5 miles of 230-kV underground transmis­sion line within existing roads and bridges.

Segment C  

  • Construction of a new cable pole at the transition point from underground to overhead near the intersection of Scranton Road and Carroll Canyon Road and installation of approximately 2.2 miles of new 230-kV transmission line and communication cable on existing 230-kV tubular steel poles within SDG&E’s existing right-of-way from the cable pole to the Peñasquitos Substation.

Additional minor modifications of the existing Sycamore Canyon and Peñasquitos substations will also be completed to allow for connection of the new 230-kV transmission line. SDG&E will temporarily utilize several construction staging yards during the project to support construction activities.  

Key Benefits

  • Improved reliability.
  • Integration of existing renewable energy into our system.
  • Elimination of potential long-term visual impacts by placing the majority of the transmission line underground.

More Information

Contact SDG&E's Public Affairs Department:

Todd Voorhees
Public Affairs Manager