The $2.4-billion RioSol clean-energy transmission project between New Mexico and Arizona gained Federal Energy Regulatory Commission approval earlier this month to sell clean energy capacity on the planned 550-mile line, a key milestone for the project, says its Phoenix-based developer Southwestern Power Group, owned by MMR Group.
“We expect to launch the open solicitation before the end of this year,” says David Getts, general manager of Southwestern Power Group, which seeks to build the proposed 1.6-GW, 500-kV high-voltage, alternating current power line and at least five substations.
RioSol, being co-developed with the New Mexico Renewable Energy Transmission Authority and first proposed in 2006, will bring wind and solar resources to market, "accessing clean power from gigawatt-scale wind farms in New Mexico and solar farms in Arizona,” according to the project website.
“There are engineering team members and consultants in New Mexico, Arizona and around the country working on the project now,” Getts says. “The primary decisions related to construction will take place in 2026,” he adds, with completion about two years later.
Project construction would follow completion of the now-underway SunZia Wind and Transmission project, which includes wind-power generation and a high-voltage direct-current line that will travel the same route as RioSol.
SunZia is billed as “the largest clean energy infrastructure project in U.S. history” and set to be in full operation by 2026.
In Nevada, the federal Bureau of Land Management is considering near-final approval of the $4.2-billion GreenLink Nevada project, which includes 700 miles of transmission lines that will tap the renewable energy potential of western and northern Nevada. Solar and geothermal electricity producers are expected to make use of the project's network of substations and high-capacity 525-kV lines to send power throughout the West.
A spokeswoman for the developer, Berkshire Hathaway Energy-owned NV Energy, said in a statement that project construction is set to start in December for the line, which will run from just outside Las Vegas to just outside Reno. It is expected to operate in May 2027, with the east-west northern leg being completed at the end of 2028.
Much of the project crosses public land, requiring extensive federal regulatory involvement, and the pace of approvals has slowed the project.
But in a May 31 filing to state regulators in Nevada, NV Energy noted the escalated cost of the Greenlink project, up from about $2.5 billion it stated in a 2021 filing, with the company citing supply chain constraints, labor rates and inflation. “The only practical alternative to the construction of Greenlink is the construction of additional generation closer to the load centers ... similar reliability cannot be achieved at a lower cost without Greenlink,” NV Energy said. It noted “considerable load growth in the state through 2034” due to rising population, electrification and more data centers in its service territory.
Carolyn Barbash, formerly NV Energy vice president of transmission development and policy, told a Las Vegas TV station late last year that Greenlink was "probably about 11 months behind" in the permitting process.
The company noted that project costs are going to be recovered over 70 years, and that revenue from wholesale transmission customers making use of the lines will defray costs for utility ratepayers.
“Once the permitting process is complete, we'll be able to share more updates about timeline and construction,” the spokeswoman said.
