Tesla's Powerpacks are connected to a wind farm in Hornsdale, owned by French renewable energy company Neoen. Jay Weatherill, a politician and current Premier of South Australia, says it's the first time the state has been able to reliably dispatch wind energy to the grid 24 hours a day, seven days a week. It was possible, of course, to capture this energy resource before -- the problem has been controlling when, and how much of the resulting electricity is fed back into the grid. With a 100MWV battery farm, the state can now power more than 30,000 homes, regardless of the weather.

"The completion of the world's largest lithium-ion battery in record time shows that a sustainable, effective energy solution is possible," a Tesla spokesperson said. "We are proud to be part of South Australia's renewable energy future, and hope this project provides a model for future deployments around the world." Tesla has built similar battery farms before; a year ago, the company completed a 20 MW system in Ontario, California that can store up to 80 MWh of electricity. It took just 90 days for the company -- that hopes to commoditize electric cars, semi-trucks and home energy storage -- to install the necessary 396 Powerpacks.