Tehachapi Renewable Transmission Project

Tehachapi Renewable Transmission Project
Name	Tehachapi Renewable Transmission Project
Location	Tehachapi Mountains, Kern County, California, Los Angeles County, California, San Bernardino County, California
Status	Operational
Owner	Southern California Edison, Pacific Gas and Electric Company, Los Angeles Department of Water and Power
Operator	California Independent System Operator
Construction	2008–2016
Capacity	4,500–5,000 MW (planned/expanded)
Voltage	500 kV, 220 kV

Tehachapi Renewable Transmission Project is a major high-voltage transmission program designed to deliver renewable energy from the Tehachapi Mountains and Mojave Desert wind and solar zones to load centers in Los Angeles, Orange County, Riverside County, and San Diego County. The initiative involved multiple utilities, regional planners, federal and state agencies, and environmental groups to integrate large-scale wind power and solar power resources into the California electricity grid, supporting state renewable portfolio standards and transmission planning efforts led by the California Public Utilities Commission and the California Energy Commission.

Overview

The project was conceived within the planning frameworks of the California Independent System Operator and the Western Electricity Coordinating Council to relieve congestion and enable development in the Tehachapi Wind Resource Area, the Antelope Valley, and adjacent renewable zones. Key proponents included Southern California Edison, Pacific Gas and Electric Company, Los Angeles Department of Water and Power, and coordinated resource planners such as the Western Area Power Administration and regional transmission organizations. Permitting and compliance required coordination with the United States Fish and Wildlife Service, the California Department of Fish and Wildlife, the Bureau of Land Management, and county governments across the affected corridors.

Route and Infrastructure

Route planning traversed the Mojave Desert, crossing federally managed lands overseen by the Bureau of Land Management and state lands administered by the California Natural Resources Agency. Major terminal interconnections include Gate 2 Substation, Monolith Substation, Whirlwind Substation, and Edison Substation near Tehachapi, with ties into Palo Verde Transmission Project-linked pathways and southern California hubs such as Sylmar Converter Station (HVDC), Victorville Substation, and Red Bluff Substation. The transmission lines include double-circuit 500 kV towers and 220 kV lines, corridor upgrades through mountain passes, and new rights-of-way negotiated with Kern County. Engineering partners included national firms experienced with projects like the Path 26 upgrades and the Pacific DC Intertie modernization.

Project Phases and Timeline

The project was executed in multiple segments with phased commercial operation dates, reflecting scheduling similar to other major Western projects like the TransWest Express Transmission Project and the SunZia Transmission Project. Initial approvals and environmental impact statements were completed in the mid-2000s, with construction commencing in 2008 and major sections energized between 2010 and 2016. Critical milestones aligned with decisions by the California Public Utilities Commission and federal authorizations under the National Environmental Policy Act administered by the United States Department of the Interior and the Bureau of Land Management.

Environmental and Regulatory Issues

Environmental review processes engaged agencies such as the National Oceanic and Atmospheric Administration for avian concerns, the United States Fish and Wildlife Service regarding endangered species like the California condor and San Joaquin kit fox, and the California Native Plant Society for rare flora assessments. Litigation and settlement negotiations involved environmental nonprofits and land trusts, invoking statutes including the Endangered Species Act and the National Historic Preservation Act with consultations under Section 106 of the National Historic Preservation Act. Mitigation measures included raptor-safe design standards informed by studies from the Scripps Institution of Oceanography and the University of California, Davis research on wildlife interactions.

Stakeholders and Ownership

Primary ownership and construction responsibilities were held by utilities such as Southern California Edison and Los Angeles Department of Water and Power, with significant contract and coordination roles for Pacific Gas and Electric Company and municipal utilities in the Los Angeles Department of Water and Power service area. Regulatory stakeholders included the California Public Utilities Commission, the Federal Energy Regulatory Commission, and regional planning entities like the California Independent System Operator and the Western Electricity Coordinating Council. Community stakeholders encompassed Kern County Board of Supervisors, tribal governments with ancestral ties in the Tehachapi and Mojave regions, and conservation organizations such as the Sierra Club and the Audubon Society.

Technical Specifications and Capacity

The system employs high-capacity 500 kV double-circuit transmission lines and 220 kV collector systems capable of conveying several thousand megawatts from multiple collection points across the Tehachapi Wind Resource Area and adjoining solar facilities such as those in the Antelope Valley Solar Ranch and Mojave Solar Project. Synchronous operations are coordinated through the California Independent System Operator market and dispatch systems, with ancillary services procured under tariff frameworks administered by the Federal Energy Regulatory Commission and the California Public Utilities Commission. Interconnection studies referenced standards from the North American Electric Reliability Corporation and transmission planning models used by the Western Electricity Coordinating Council and the National Renewable Energy Laboratory.

Economic Impact and Benefits

The project enabled accelerated development of renewable projects, stimulating investment from independent power producers and developers, similar to activity seen with the Alta Wind Energy Center and Tejon Ranch projects. Economic benefits included construction jobs, local contracting opportunities, grid reliability improvements, and contributions toward California's Renewable Portfolio Standard goals enforced by the California Energy Commission. Regional economic development involved coordination with workforce programs and agencies such as the California Employment Development Department and infrastructure financing instruments influenced by state legislation like Assembly Bill 32 and renewable energy policy initiatives promoted by successive Governors of California.

Category:Energy infrastructure in California Category:High-voltage transmission lines in the United States