Tesla Secures Contract to Build 129‑MWh Lithium‑Ion Battery, the Largest in the World, in South Australia

Tesla has secured a contract to construct the world’s largest lithium‑ion battery in South Australia. The new system will store 129 MWh of energy—three times the capacity of the current global leader—according to CEO Elon Musk.

The battery will be powered by renewable output from Neoen’s Hornsdale wind farm, a French utility that supplies clean energy to the region. Tesla will employ a design framework similar to its Powerpack platform, the industrial storage solution it launched in 2015.

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In March, Musk announced that Tesla could have the battery operational within 100 days or the project would be free. The company recently completed an 80 MWh test run in California, assembling the battery farm in just 90 days, demonstrating its rapid deployment capability.

The project is a key component of South Australia’s $550 million AUD ($380 million USD) energy strategy, developed after a statewide blackout. While some state politicians argue that the move to renewables was rushed, others contend that rising energy demand necessitated swift action.

"You can charge the battery when surplus power is available at low cost, then discharge it during peak demand periods, effectively lowering the average cost for customers," Musk explained.

Tesla already operates the world’s largest battery manufacturing facility, the Gigafactory. Adding this 129‑MWh battery to its portfolio underscores the company’s leadership in energy storage innovation, even as the firm faces recent market challenges and a stock decline from $365 to $310.