Sunrise Powerlink Construction Underway

After receiving regulatory approval, SDG&E began construction on non-transmission related facilities that are necessary to support the Sunrise Powerlink’s main transmission line in September 2010.  These efforts included developing the Sunrise Powerlink team’s headquarters in the community of Alpine, several construction staging yards and other project support sites.  This was followed by the start of construction on the main transmission line in November 2010, which occurred on the 6.2-mile underground section in Alpine.

Sunrise Powerlink construction currently is progressing in several areas along the project’s 117-mile route from the Imperial Valley to San Diego.  SDG&E has installed more than 75 percent of the concrete vaults and more than 10 percent of the cable in the underground segment of the project in Alpine.  Additionally, construction has started on the overhead portion of the project, including the completion of the first transmission tower in March 2011 near the community of Boulevard.  The overhead construction is occurring on non-federal and Bureau of Land Management (BLM) land.  More than 50 percent of the overhead portion of the Sunrise Powerlink will be built using the “Sun Bird” air-crane helicopter to avoid impacts to sensitive habitat.

Other ongoing construction work includes installing numerous tower foundations, assembling towers, upgrading seven existing substations to accommodate the increased power from the line and constructing the new Suncrest Substation.  In total, this $1.883 billion project will consist of 421 steel lattice towers supporting overhead transmission lines, as well as the 6.2 mile underground segment in Alpine.

One way to look at the transmission line project is to divide it into five “links” or segments.  Link 1 starts at the Imperial Valley Substation, crosses the region’s low desert running parallel to the existing Southwest Powerlink and then rises over the mountain ridges of Eastern San Diego County, reaching an altitude of 4,900 feet.  Link 2 of the line continues west through the Cleveland National Forest and north of Campo until it reaches Link 3, which is the site of the new Suncrest Substation east of Alpine and west of Japatul Valley Road.  Link 4 is the 6.2 mile underground segment along Alpine Boulevard.  Link 5 consists of two segments of 230kV overhead transmission line on either side of the Alpine underground portion, one that runs from the Suncrest Substation to Alpine and the other that starts west of Alpine and runs to the Sycamore Canyon Substation – where the project connects to the existing SDG&E system.  

The Sunrise Powerlink is being constructed under some of the most rigorous environmental and safety requirements ever placed on a transmission line project.  The project is implementing approximately 320 environmental and cultural mitigation measures requiring nearly 1,000 separate tasks.  SDG&E will continue to focus on ensuring safety, reducing impacts to the environment and providing information to the community throughout the project’s construction.

Upon completion in 2012, the Sunrise Powerlink will bring unparalleled benefits to San Diego and Imperial Counties.  It will bolster reliability for the region’s power grid, access vast sources of renewable energy and help boost the local economy.  The new transmission line will deliver up to 1,000 megawatts of clean power, or enough energy for 650,000 homes.  As only the second 500-kV transmission line in the region, it will help solve the area’s critical transmission shortage.  In addition, the project will open up new economic development opportunities, creating 400-500 local construction jobs and facilitating thousands of “green” jobs from associated renewable energy projects in the region.  In total, Sunrise Powerlink construction will inject $1.7 billion directly into the U.S. economy.

The project was approved by the California Public Utilities Commission (CPUC) in December 2008, the BLM in January 2009 and the U.S. Forest Service (USFS) in July 2010.