SDG&E Files Application to Increase Reliability in South Orange County

Substation, Transmission Upgrade Needed to Meet Region's Growth

May 18, 2012

SAN DIEGO, May 18, 2012 /PRNewswire/ -- San Diego Gas & Electric (SDG&E) today submitted an application to the California Public Utilities Commission (CPUC) for approval of a project designed to increase the reliability of the substation and transmission system in the northern part of SDG&E's service area.  The South Orange County Reliability Enhancement project would be located within the cities of San Juan Capistrano, San Clemente and the unincorporated areas of Orange County and is designed to increase reliability in southern Orange County.

"The energy demand in Orange County has more than tripled over the last 26 years," said Michael R. Niggli, SDG&E's president and chief operating officer.  "By upgrading our transmission and substation infrastructure in this area, SDG&E not only will increase reliability, but also provide additional capacity and flexibility for meeting our customers' needs."

The project has several components:

  • Upgrade the existing transmission lines that connect the substations in San Juan Capistrano and San Clemente by replacing an existing 138-kilovolt (kV) transmission line with a new 230-kV double-circuit line.  Most of the transmission line work will be conducted within SDG&E's existing right of way. 
  • Rebuild the 1950s-era 138-kV/12-kV substation and build a new substation in San Juan Capistrano to improve the reliability and capacity of the region.  The Capistrano Substation provides electric service to the majority of customers in San Juan Capistrano.
  • Reconfigure existing 138-kV transmission lines at SDG&E's substation in San Clemente, which is located on Marine Corps Base Camp Pendleton on the border of San Diego and Orange Counties, in the midst of undeveloped land.

While the existing transmission lines have served the area well, community and commercial growth, as well as technological and electronic advances such as flat-screen TVs, DVDs, DVRs and computers, are adding to the overall electrical demand on the system.  At times, these transmission lines run at near capacity – like a freeway at rush hour – leaving little room for a sudden surge in demand, such as when air conditioning units kick on during a heat wave or a transmission line trips out of service.  Not only has the south Orange County 138-kV transmission network reached its capacity, its current design is vulnerable to service interruptions due to potential transmission failures.  The proposed project will resolve these areas of concern and enhance SDG&E's delivery of safe, reliable electric power to south Orange County.

The California Independent System Operator approved the South Orange County Reliability Enhancement project last year as part of SDG&E's 2010/2011 Transmission Plan.  SDG&E then conducted extensive outreach to elected officials and community leaders, as well as to businesses and residents along the proposed route from San Clemente to San Juan Capistrano.

Along with its application for a Certificate of Public Convenience and Need, SDG&E submitted an extensive environmental assessment, which analyzes the potential environmental impacts of the proposed project. 

If the project is approved by the CPUC, construction could begin as soon as the end of 2013 with completion expected in 2017.

SDG&E is a regulated public utility that provides safe and reliable energy service to 3.4 million consumers through 1.4 million electric meters and more than 850,000 natural gas meters in San Diego and southern Orange counties.  The utility's area spans 4,100 square miles.  SDG&E is committed to creating ways to help customers save energy and money every day.  SDG&E is a subsidiary of Sempra Energy (NYSE: SRE), a Fortune 500 energy services holding company based in San Diego.  



For further information: Jennifer Ramp of San Diego Gas & Electric, 1-877-866-2066,, Twitter: @sdge