Elon Musk's Tesla to build world's biggest lithium ion battery to secure power for South Australia

South Australia will be home to the world's largest lithium ion battery thanks to a historic agreement between Tesla and the State Government.

The Hornsdale Wind Farm is still under construction.

And Tesla boss Elon Musk is promising to build it in 100 days, or it's free.

Tesla will build the 100-megawatt battery which will store energy from French renewable company Neoen's Hornsdale Wind Farm near Jamestown, which is still under construction.

The project will be in place before summer.

Mr Musk's '100 days or it's free' pledge starts once the grid interconnection agreement has been signed.

Read the ABC News story - “Elon Musk's Tesla to build world's biggest lithium ion battery to secure power for South Australia.”