Building a better grid, project by project
Viridon’s projects strengthen and expand America’s high-voltage grid, meeting the needs of transmission system operators, power generators, data centers, and ultimately all utility customers.
Portfolio overview
The combined Viridon and Blackstone team has spearheaded the development, construction, and operation of major grid-transforming projects across America.
$ B
competitive awards $ B
transmission project experience GW
renewable energy integration
East West Tie Line
Location: Ontario (IESO)
Details: 280-mile, double-circuit 230 kV transmission line.
Background: Completed in 2022, this project enabled the replacement of inefficient generation in Northwestern Ontario with cleaner and cheaper sources of power while enhancing reliability. The project consortium included both a Canadian energy company and a pension fund, together with First Nation communities along the route, and involved extensive environmental consultations. Current Viridon team members, while at NextEra Energy, led the initial development and provided oversight and support at all stages of the project.
Empire State Line
Location: New York (NYISO)
Details: 20-mile, single-circuit 345 kV transmission line with two 345 kV switchyards and a Phase Angle Regulator (PAR).
Background: Completed in 2022, the project unlocked approximately 3,700 MW of renewable energy from Niagara Falls and Canada for delivery throughout New York. Originally selected by NYISO in 2017 as the first competitive project in New York awarded pursuant to FERC Order 1000. Current Viridon team members, while at NextEra Energy, provided oversight and support at all stages of the project.
GridLiance West
Location: Nevada (CAISO)
Details: 167-mile, 230 kV transmission system with pending 500 kV upgrades.
Background: GridLiance, a predecessor Blackstone portfolio company, partnered with a local cooperative utility in Nevada to acquire and upgrade the high-voltage system. Members of Viridon’s board, and current Viridon team members while at NextEra Energy, led these efforts from inception in 2016 until the recent approval by CAISO of 500 kV system upgrades to further increase the access of Nevada’s abundant solar resources to the California market.
Humboldt
Location: California (CAISO)
Details: Combined 416 miles of single-circuit 500 kV transmission line and the New Humboldt 500/115kV substation.
Background: CalGrid, a Viridon subsidiary, was selected by CAISO in 2025 to finance, construct, own, operate, and maintain two transmission projects in Northern California: New Humboldt–Collinsville and New Humboldt–Fern Road. Currently under development and planned for completion in 2034, the Humboldt projects will enhance the state’s high-voltage transmission backbone, improving regional reliability while facilitating the integration of renewable energy.
Lone Star Transmission
Location: Texas (ERCOT)
Details: 350-mile, double-circuit 345kV transmission line and 11 high-voltage stations.
Background: Completed in 2013 as part of a statewide buildout of the high voltage grid to accommodate the integration of 10,000 MW of wind energy. Current Viridon team members, while at NextEra Energy, provided oversight and support at all stages of the project, from permitting through to financing, construction, and operations.
Path 15
Location : California (CAISO)
Details: 84-mile, single-circuit 500 kV transmission line.
Background: Viridon acquired the Path 15 Project, which links Northern and Southern California and is a vital component of the state’s energy infrastructure. It was developed through a unique public-private partnership with the Western Area Power Administration, which owns and maintains the line.
Suncrest SVC
Location: California (CAISO)
Details: 230 kV, 300 MVar static VAR compensation (SVR) facility.
Background: Completed in 2020, the project supports the grid in and around San Diego by injecting or absorbing reactive power to maintain voltage levels, which helps integrate renewable energy. Originally selected by CAISO in 2015 as the first competitive project in California awarded to a non-incumbent utility pursuant to FERC Order 1000. Current Viridon team members, while at NextEra Energy, provided oversight and support at all stages of the project.
Trans Bay Cable
Location: California (CAISO)
Details: 53-mile, ±200 kV High-Voltage Direct Current (HDVC) transmission line and two converter stations.
Background: Completed in 2010, this first-of-its-kind submarine project can deliver 400 MW from the East Bay to the San Francisco, meeting 40% of the city’s peak electrical power needs while reducing energy costs and environmental impacts for California customers. Current Viridon team members, while at NextEra Energy, led the acquisition of the project in 2019 and provided oversight and support to the ongoing operations, maintenance, and management of the project.
Wisconsin Southeast
Location: Wisconsin (MISO)
Details: 106 miles of 345 kV lines and four 345 kV substations.
Background: Viridon Midcontinent, a Viridon subsidiary, was selected by MISO in 2026 to develop the Wisconsin Southeast Competitive Transmission (WISE) project. The WISE project is designed to strengthen reliability and address long-term system needs in southeastern Wisconsin.
Where we operate
Built to scale nationally
Viridon is qualified to develop new transmission projects nationwide. Our team has deep experience across all regional power systems, applying market-specific insight while maintaining a consistent, repeatable approach to project delivery.
