The 100-megawatt battery in South Australia, scheduled to be switched on in the coming days, will provide security to the state's electricity grid and will store enough energy to power 30,000 homes for about an hour.
In March, billionaire businessman Mike Cannon-Brookes threw down the gauntlet to Musk questioning Tesla’s claim that it could end recurrent blackouts in South Australia and do it fast.
"The world's largest lithium ion battery will be an important part of our energy mix, and it sends the clearest message that South Australia will be a leader in renewable energy with battery storage," the state's Premier, Jay Weatherill, said in a statement.
"An enormous amount of work has gone in to delivering this project in such a short time," he added.
The project is part of a wider plan to ensure stable energy supply and ease frequent power outages in South Australia, the country’s most wind power-dependent state, which has suffered recently from energy shortages.