ContourGlobal Breaks Ground on Major Arizona Solar-Plus-Storage Project
ContourGlobal has started building Project Sterling, a 509 MW solar and 1.4 GWh battery facility in Arizona, to supply Tesla with over 1 TWh of clean power annually under a long-term agreement.
ContourGlobal has commenced construction on Project Sterling, a combined solar and battery storage facility in Mohave County, Arizona. The October 7, 2026 groundbreaking ceremony in Topock marked the visible start of major on-site work, bringing together company executives, state and local officials, industry partners, and community members.
Project scale and technology
Project Sterling is expected to become ContourGlobal’s largest renewable asset worldwide once operational. Located about 20 miles north of Lake Havasu City, the facility will extend across more than 2,000 acres in the Mojave Desert. The project combines 509 megawatts-peak of solar photovoltaic capacity with a 360 megawatt battery storage system capable of holding 1.4 gigawatt-hours of electricity.
The installation will require more than 760,000 solar modules and over 300 battery storage containers. The battery system uses lithium iron phosphate technology with liquid cooling and integrated fire protection, providing four hours of storage capacity.
| Component | Specification |
|---|---|
| Solar Capacity | 509 MW-peak / 450 MW-alternating current |
| Battery Capacity | 360 MW / 1.4 GWh |
| Solar Modules | >760,000 |
| Battery Containers | >300 |
Tesla agreement and energy output
Once operational, the plant is expected to generate more than 1.1 terawatt-hours of electricity per year. This output will be supplied under a long-term power purchase agreement with Tesla, covering around 90% of expected production. ContourGlobal announced the Tesla PPA in July 2026.
The agreement is among the largest corporate solar-plus-storage PPAs signed for a single hybrid renewable energy facility in the United States. It represents ContourGlobal’s largest PPA to date. This output is enough to meet the average residential needs of a city with 100,000 to 120,000 inhabitants.
Construction timeline and workforce
Construction began in mid-2026 with an average workforce of 400 people and is scheduled for commercial operation in early 2028. Off-site physical work started earlier, in June 2025. ContourGlobal began building Polaris Road, the project’s 5.2-mile access route linking to historic Route 66, in July 2026.
First energization is targeted for the third quarter of 2027. Work will continue through 2028, involving local teams in civil work, road building, and site logistics.
Grid integration and regional impact
The facility is designed to deliver clean electricity for up to 16 hours a day by storing solar generation for use after sunset. Project Sterling is physically connected to the Western Area Power Administration grid and holds firm transmission rights to access the California Independent System Operator market.
ContourGlobal plans to use a pseudo-tie arrangement to serve Tesla’s contracted electricity needs. The company says this arrangement can support regional grid reliability by facilitating transfers across the Western Interconnection. Antonio Cammisecra, ContourGlobal’s president and chief executive, spoke at the ceremony. "Today’s ceremony marks the visible beginning of our partnership with Mohave County, the State of Arizona and our customer, Tesla," he said.
The privately financed project secured an equity bridge loan from a syndicate of international banks to support construction. ContourGlobal acquired the project at the development stage in December 2024 and later redesigned it to meet Tesla’s requirements. Following this project and the recent completion of Black Hollow Sun in Colorado, ContourGlobal’s U.S. portfolio now totals 2.4 gigawatts in operation or under construction. This portfolio comprises 1.2 gigawatts of thermal generation and 1.2 gigawatts of renewable energy and storage capacity across several states. Commercial operation is scheduled for the first quarter of 2028, at which point the facility will begin delivering power to Tesla under the long-term PPA.
