The world's largest lithium-ion battery has officially been turned on in South Australia, as the state tries to solve its energy woes.
Premier Jay Weatherill flicked the switch at Jamestown on Friday, saying it was history in the making.
"South Australia is now leading the world in dispatchable renewable energy, delivered to homes and businesses 24/7," Mr Weatherill said.
"I want to express my gratitude to the workers who have constructed this battery. They have every right to be proud of what they have constructed."
By coming in ahead of schedule, Tesla tech billionaire Elon Musk has made good on his promise to build the 100-megawatt facility in 100 days or provide it free.
The battery is paired to the neighbouring Hornsdale Wind Farm, owned by French company Neoen, and aims to bring added reliability and stability to the state's electricity grid.
That reliability was tested before the battery's official launch when it began dispatching around 59 megawatts into the state's electricity network on Thursday afternoon as the state hit temperatures above 30C.
The facility has the capacity to power 30,000 homes for up to an hour in the event of a severe blackout but is more likely to be called into action to even out electricity supplies at less critical times.
Its production came after a now-famous Twitter exchange between Mr Musk and Australian tech billionaire Mike Cannon-Brookes, who challenged the Tesla boss to help solve SA's energy problems.
Mr Musk responded that if he couldn't build a 100-megawatt battery in 100 days from signing the contract, he would provide it for free.
But the company easily beat the deadline, finishing the battery in about 63 days, though it did get a head start on construction.
"The completion of the world's largest lithium-ion battery in record time shows that a sustainable, effective energy solution is possible," Tesla said in a statement on Friday.
Mr Musk was not at the launch on Friday.
The battery, along with newly installed back up diesel generators, form part of the state government's $550 million energy plan to bring reliability and security to the grid.
The plan was developed after the statewide blackout in September last year.
