Tesla and energy company ContourGlobal have executed a long-term power purchase agreement under which Tesla will procure roughly 1 terawatt-hour of renewable electricity per year from Project Sterling, a hybrid solar photovoltaic and battery energy storage facility being developed in Arizona.

Project Scale and Significance

Project Sterling is configured with approximately 509 megawatts of solar generation capacity paired with more than 1.4 gigawatt-hours of battery energy storage. ContourGlobal has described the project as the largest renewable asset in its portfolio. The deal is also being characterized as one of the largest corporate PPAs ever signed for a single solar-plus-storage plant in the United States. ContourGlobal noted that securing the agreement represents its biggest PPA to date, a milestone the company linked to the scale and structure of the project itself.

Construction and Timeline

Physical construction on Project Sterling began in 2025, with off-site preparatory work initiated in part to meet subsidy qualification deadlines. Commercial operations are targeted for 2028, at which point electricity delivery under the PPA is expected to commence. The Arizona location positions the project within one of the country's higher-resource solar regions, suited to the generation volumes called for under the agreement.

Corporate Offtake Context

For Tesla, the agreement represents a significant long-term energy procurement commitment. The company has expanded its energy division in recent years, encompassing both stationary battery storage products and broader power supply arrangements. Contracting for approximately 1 TWh annually from a single facility underscores the scale at which Tesla is now seeking to secure renewable electricity supply. The PPA structure, in which Tesla serves as the offtaker for power generated by a third-party developer, is a common mechanism for large corporate buyers to access clean energy without directly owning generation assets.

ContourGlobal's Portfolio Move

For ContourGlobal, Project Sterling marks a notable expansion into large-scale hybrid renewables in the United States. The project's combination of utility-scale solar and a substantial battery storage component reflects broader industry trends toward co-located generation and storage, which can provide more consistent power delivery and improve a project's value under long-term contracts. Having Tesla locked in as the offtaker provides the revenue certainty typically required to move a project of this magnitude through financing and into construction.