When work begins in early 2023, the more than $8-billion SunZia transmission and wind project will become the nation’s largest single-phase renewable energy project, according to its developers. This 550-mile bi-directional ± 525 kV high-voltage direct current transmission line will extend from central New Mexico to south-central Arizona.

With capacity to transport up to 3,000-plus MW to 2.5 million power users in Arizona, California and New Mexico, the SunZia transmission line will carry wind energy generated at farms in Lincoln, Torrance and San Miguel counties in New Mexico.

When completed in late December, Pattern Energy Group LP’s 1,050-MW Western Spirit Wind facility in New Mexico was the largest renewable energy project in U.S. history, says Jeremy Turner, the firm's director of New Mexico project development. SunZia Wind alone will be three times the size of Western Spirit, he contends.

In September 2016, Pattern Energy was selected by SouthWestern Power Group as the anchor tenant for the SunZia Transmission line. Pattern Energy is also developing SunZia Wind.

“SunZia Transmission will create a clean power superhighway for millions of Americans by opening access to huge, largely-untapped wind energy resources in New Mexico,” said Mike Garland, CEO of San Francisco-based Pattern Energy in a prepared statement.

The private developer/operator of wind, solar, transmission and energy storage projects recently acquired the SunZia Transmission project from SWPG, which develops utility-scale generation and transmission assets in the Southwest as a wholly owned subsidiary of Baton Rouge-based MMR Group Inc.

“We are creating and implementing the largest clean energy infrastructure project in American history, demonstrating the vast potential of New Mexico’s wind power and the regions’ ability to bring large interstate infrastructure to reality,” Garland said.

SunZia Transmission and Pattern Energy have partnered with the New Mexico Renewable Energy Transmission Authority to develop the project. Meanwhile, Pattern Energy and SouthWestern Power Group will continue to work together with SWPG to provide support services, including permitting real property, engineering and construction.

SouthWestern Power Group will maintain ownership of a second 500-kV high voltage-alternating current transmission line for HVAC, El Rio Sol Transmission, largely adjacent to the SunZia line, notes David Getts, general manager at SouthWestern.

Both privately funded, the SunZia transmission and wind project will create more than 2,000 construction jobs at peak, Turner says, with as many as 150 permanent staff to operate and maintain the projects.

Pattern Energy expects to begin full construction of the SunZia project in 2023, with start of operations for the transmission line expected in 2025 and wind power in early 2026.