Tesla and ContourGlobal finalized a long-term power purchase agreement marking one of the largest solar-plus-battery storage corporate contracts from a single facility in the United States. Project Sterling, a hybrid solar and battery energy storage system in Arizona, will supply Tesla with approximately 1 terawatt-hour of electricity annually under the deal.

The facility represents ContourGlobal's largest renewable asset, combining photovoltaic generation with more than 1.4 gigawatt-hours of battery storage capacity. This scale positions Sterling to deliver consistent power across multiple hours of operation, addressing the intermittency challenges that solar-only installations face.

The agreement reflects Tesla's aggressive procurement strategy for clean energy, as the electric vehicle manufacturer seeks to reduce reliance on grid electricity and associated emissions from fossil fuel generation. Long-term corporate PPAs lock in predictable power costs while ensuring renewable developers secure sustained revenue streams necessary for project financing.

Arizona's solar resource potential and existing transmission infrastructure made Project Sterling feasible. The state receives approximately 5.8 kilowatt-hours of solar irradiance per square meter daily, among the highest in the continental United States.

Battery storage capacity proves essential for this contract structure. Without onsite batteries, Tesla could only access solar power during daylight hours. The 1.4 GWh system allows ContourGlobal to store excess midday generation and dispatch it during evening peak demand periods, enabling the 1 terawatt-hour annual commitment across a full 24-hour cycle.

Corporate renewable PPAs have accelerated adoption of utility-scale solar installations. Companies including Microsoft, Google, and Amazon have executed similar megawatt-scale agreements, collectively driving billions in renewable energy investment.

This deal underscores market momentum toward solar-plus-storage hybrid facilities. Declining battery costs, dropping from $1,200 per kilowatt-