The lithium battery and subsequent bet are part of South Australia's 530 million dollar energy plan alongside the construction of backup generators.
The battery, according to Hornsdale Power Reserve, takes up less than 2.5 acres of land and has the ability to power 30,000 homes for an hour during a blackout.
"Neoen is pleased to be able to reinforce its Australian footprint through the achievement of the Hornsdale Wind Farm & Battery and is extremely proud to contribute further to the development of renewable energy in Australia".
The world's biggest lithium-ion battery has plugged into an Australian state grid, an official said Friday, easily delivering on Tesla Inc. chief executive Elon Musk's 100-day guarantee.
Musk accepted the challenge, adding if he couldn't produce the battery within 100 days of signing the contract the battery and installation would be free.
South Australia suffered a severe blackout a year ago that left 1.7 million people without electricity, prompting Australian PM Malcolm Turnbull to lash out at state regulations that encouraged what he believed to be a too heavy a reliance on renewable energy: the Australian Energy Market Operator found that the blackout was caused by too sensitive protection mechanisms at some windfarms in South Australia.
Tesla Powerpacks in South Australia, which make up about half of the new Australian mega-battery.
Highlighting industry hopes for the take-up of battery storage, Tesla CEO Elon Musk visited the site some 225 kms (141 miles) north of the state capital Adelaide in July, hailing the battery as "just the beginning".
The Australian grid operator has warned of potential shortages of gas-fired electricity across southeast Australia by late next year.
The manufacturer, Tesla, says the lithium-ion device made up of PowerWall 2 batteries is the "largest" by storage and "most powerful" of its type in the world.
Although the country still relies on fossil fuels for two-thirds of its electricity, wind energy is a large contributor in South Australia.