The Bureau of Land Management at the end of last week approved the construction of a 500 kV transmission line connecting Central Arizona and Southern California that will move up to 3.2 GW of solar power in the Southwest Desert. The Ten West Link project, most of which will be on federal land and in existing utility corridors or alongside utility infrastructure, is expected to be online in 2023.
Avoiding costly new rights-of-way is a major advantage, Neil Millar, California Independent System Operator vice president of Transmission Planning, said of the project’s chosen route. Because it “parallels the existing Palo Verde-Colorado River 500 kV line, it will reduce the risk of losing transmission capacity should that original line be out of commission for any reason,” he added in a blog late last year.
“The project will provide critical transmission infrastructure to support the development of future utility-scale solar energy resources and will boost the reliability of the bulk power system for millions of customers in Central Arizona and Southern California,” BLM stated. The Bureau recently approved three new large solar and battery projects to be built on public land in Riverside County.
The 126-mile high voltage project, estimated to cost $390 million, will run from the Arizona Public Service’s Delaney Substation near Tonopah in Mariposa County to Southern California Edison’s Colorado River substation in Blythe, Riverside County, with almost 22 miles in the state. BLM expects construction to start in September.
The transmission project will connect directly to CAISO’s market, allowing it to “provide an additional 1,000 MW of deliverability for resources that can provide capacity under the Resource Adequacy program,” Millar said.
CAISO’s 2014-15 Transmission Plan stated an additional high-voltage transmission connection between the Delaney and Colorado River substations was necessary for reliability and to increase the level of renewable energy supplying California as required by state law. Last November, the California Public Utilities Commission approved a construction permit for the high voltage project.
CAISO customers will pay the full cost of the project.
Ten West Link was one of the first economic competitive solicitation projects CAISO’s board approved “because it promotes the economic efficiency of the ISO controlled grid and considers federal and state environmental and other policies affecting the provision of energy,” said Anne Gonzales, grid operator spokesperson.
CAISO selected developer Starwood Energy Group affiliate DCR Transmission, Limited Liability Corp. to construct and operate the project following a competitive bidding process. Starwood owns a minority interest in some transmission lines in California, Arizona, and Nevada, and developed wind generation in Texas and gas generation in California.
The transmission project approval follows federal green lights for three major solar projects in the desert in eastern Riverside County. Last week, BLM approved the building of the 500 MW Oberon solar project that includes 200 MW of battery storage. Developer Intersect Power just began building the project and it’s estimated to be online by September 2023. On June 13, BLM approved Clearway Energy’s 265 MW Arica and 200 MW Victory Pass solar projects, which will provide a combined 400 MW of battery storage near Desert Center. The estimated operation date for Arica and Victory Pass projects is September 2023, according to BLM’s Kate Miyamoto.
The three solar projects are the first ones to be approved pursuant to the stakeholder-approved Desert Renewable Energy Conservation Plan. The established plan allows 10.8 million acres managed by the BLM to be used for renewable energy development.