55 days.

That was the time between Tesla signing off on the 100-megawatt battery in South Australia and its completion.

After an audacious twitter bet with Atlassian CEO Mike Cannon-Brookes in March this year, Musk claimed he could build South Australia the world’s biggest lithium-ion battery in under 100 days or it would be free.

Talks soon got serious between Musk and the South Australian government, and on September 29 a contract was signed between Tesla and the Australian Energy Market Operator, cementing the deal and starting the clock on Musk’s 100 days (although Tesla had started construction prior to this.)

It is believed that in making this bet with the South Australian government, the Tesla founder was putting more than $50 million on the line.

On Thursday last week Musk tweeted to his 15.3 million followers, “Congratulations to the Tesla crew and South Australian authorities who worked so hard to get this manufactured and installed in record time!”

The following day Cannon-Brookes said that he had, “Never been so happy to lose a bet.”

The Tesla Powerpacks have now been connected to the Neoen Hornsdale wind farm, with testing to begin shortly.

While renewable energy produces around 40% of South Australia’s energy, a string of severe blackouts last summer caused many to question the effectiveness of these sources.

The battery is designed as a way to store energy at times when solar or wind energy is not being generated, and prevent future blackouts, with the battery expected to be able to power 30,000 homes for over an hour if needed.

It comes as part of South Australia’s $550 million energy plan.

The site, located north of Adelaide in the Jamestown, will serve as a back-up power source for the state, which last summer experienced a series of lengthy blackouts caused by a storms and high energy consumption of air conditioners.

South Australian Premier, Jay Weatherill, promised that the new battery could fix South Australia’s energy woes.

“While others are just talking, we are delivering our energy plan, making South Australia more self-sufficient, and providing back up power and more affordable energy for South Australians this summer,” he said following the completion of the battery.

“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 renewable energy with battery storage.

“An enormous amount of work has gone in to delivering this project in such a short time, and I look forward to visiting Jamestown next week to personally thank those who have worked on this project.”

The site will be officially opened this week, with Musk expected to attend the launch.