Tesla CEO Elon Musk announced July 7, 2017 that his company will use its giant battery, the Powerpack, to build a 100 megawatt (MW) lithium-ion battery system in South Australia. When it is completed, it will be the largest battery storage product in the world. 
The batteries will store energy produced by a local wind farm in Jamestown, South Australia. The battery system will have the ability to power tens of thousands of homes.
Tesla wrote in a statement:
“The Tesla Powerpack system will further transform the state’s movement towards renewable energy and see an advancement of a resilient and modern grid.
Upon completion by December 2017, this system will be the largest lithium-ion storage project in the world and will provide enough power for more than 30,000 homes, approximately equal to the amount of homes that lost power during the blackout period.” 
By storing energy during off-peak hours and then recharging that energy during peak hours, utility companies will be able to cut costs and reduce reliance on non-renewable energy sources.
The Powerpack and Tesla’s at-home battery, the Powerwall, have been commercially available since 2015. The company released upgraded versions of both systems and unveiled a solar roof product. Tesla began accepting orders for the solar roof in March 2017.
Tesla beat out 91 international bidders for the project to build a 100 MW lithium-ion storage solution, most likely due to Musk’s clout and proven track record, not to mention his promise to waive the installation fee.
The Hawaiian island of Kauai is currently powered by Tesla’s Powerpack technology. Medium-sized businesses, too, are starting to rely on Tesla for energy storage, including the Sierra Nevada Brewing Co. Additionally, Los Angeles now uses a Powerpack storage facility Tesla built into Southern California Edison’s Mira Loma substation in Ontario, California, to power 15,000 homes.
 Business Insider
 The Verge