Southern California Edison (SCE) has completed upgrades to its West of Devers transmission lines, increasing capacity to facilitate more than 7GW of renewables and battery storage capacity in the coming years.
The transmission lines bring power from desert areas in the eastern part of California to the population centres of the Inland Empire and San Gabriel Valley.
“Completing the West of Devers project is another giant step in our ability to deliver clean energy throughout our service area,” said Kevin Payne, SCE president and CEO.
“While distributed energy resources like rooftop solar and battery energy storage will contribute to decarbonising our electric infrastructure, large-scale generation and reliable delivery of renewable energy will be vital to achieve California’s ambitious climate goals.”
The project consisted of removing and replacing conductors and supporting structures of four separate circuits of 220kV transmission lines through the existing 48-mile corridor from the Devers substation near Palm Springs to the Vista and San Bernardino substations in Grand Terrace and San Bernardino, respectively, about 200 miles of power lines.
The upgrades triple the capacity of power delivery from 1600MW to 4800MW, which helps with system reliability into the Southern California population centres during peak summer demand.
As part of the West of Devers Project, SCE entered into a transaction with Morongo Transmission for it to invest in the project, which allowed SCE to build the project across the Morongo Indian Reservation.
The total cost of the project was $740m, with Morongo Transmission expected to invest $400m later this year (upon regulatory approval).
In 2017, SCE received all necessary environmental permits and regulatory approvals to start construction, which began in early 2018.
West of Devers went into service about five months before its originally projected timeframe.
SCE built the project in an environmentally beneficial way by rebuilding within a corridor containing existing transmission lines, despite the unique operational challenges of this approach.
The project spans several Riverside and San Bernardino communities, including Banning, Beaumont, Calimesa, Colton, Grand Terrace, Loma Linda, Redlands and other unincorporated areas of Riverside and San Bernardino counties.
The corridor also passes through the reservation trust land of the Morongo Band of Mission Indians, a key partner with SCE in its bid to obtain environmental permits.