Tesla has completed the construction of what is believed to be the world’s largest lithium ion battery, the government of South Australia has announced.

Tesla was given 100 days to complete the 100 MW/129 MWh project after being awarded the contract in July 2017. It was already halfway through installation of the battery packs when it signed a grid connection contract in September.

The battery is located at a wind farm run by French firm Neoen and is part of an energy strategy announced by South Australia Premier Jay Weatherill earlier this year. It is composed of a series of PowerWall 2 batteries.

The plan also includes development of a natural gas-fired power plant and the creation of an energy security target.

“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,” said Weatherill said in a statement.

South Australia is Australia’s most wind-dependent state. The battery will be used for load shedding operations as well as the provision of system security services.