Tesla, the electric car business owned by billionaire Elon Musk, is set to build the world's largest ever lithium-ion battery.
Ever the entrepreneur, Mr Musk and Lyndon Rive, the head of Tesla's battery division, proposed building an energy storage facility in South Australia following total blackouts across the state following a storm in March 2016.
South Australia has struggled to access renewable energy supplies and retain power for residents in recent years.
As a maker of electric automobiles, Tesla has also invested heavily in energy storage and solar panel technology - and it believes its technology could develop far beyond vehicles and supply power to the grid.
Mr Musk stressed to Mike Cannon-Brookes, the Australian entrepreneur behind the American technology company Atlassian, that Tesla was capable of meeting South Australia's energy needs.
Mr Musk tweeted that Tesla "will get the system installed and working 100 days from contract signature or is free. That serious enough for you?"
That deal has now been agreed, and will see Tesla manufacture a 129MWh battery in Jamestown, a town with a population of less than 1,500 people, just over 120 miles north of Adelaide.
"This is not a minor foray into the frontier," said Mr Musk. "I'm pretty darn impressed with South Australia willing to do a project of this magnitude that is beyond anything else in the world.