Tesla CEO Elon Musk promised back in March that his electric car company, which also owns solar energy provider SolarCity, could help the state of South Australia with its routine weather-caused blackout issues. At the time, Musk said Tesla was so serious about the endeavor, he wrote on Twitter that the project could be completed within 100 days of a signed deal or it’d come free of charge. Now, Tesla is getting the opportunity to make good on that promise, as the company has won the government of South Australia’s bid to build what would be the world’s largest lithium-ion battery.

Tesla beat out 91 international bidders for the project — perhaps because of Musk’s clout (and proven track record) and his audacious claim to waive the installation fee — to supply South Australia with a 100-megawatt lithium-ion energy storage solution. It would be the largest lithium-ion battery system ever made, and it appears to involve a substantial scaling up of Tesla’s current commercial Powerpack system first unveiled back in 2015.

This will be the highest power battery system in the world by a factor of 3. Australia rocks!! https://t.co/c1DD7xtC90 — Elon Musk (@elonmusk) July 7, 2017

The battery will store wind energy generated from French company Neoen’s Hornsdale Wind Farm, located outside Jamestown, South Australia. “The Tesla Powerpack system will further transform the state’s movement towards renewable energy and see an advancement of a resilient and modern grid,” Tesla wrote in a statement issued yesterday. In simple terms, by storing solar energy during off-peak hours and then discharging that energy during peak hours, utilities companies are able to cut costs and reduce reliance on non-renewable energy sources.

“Upon completion by December 2017,” the statement goes on, “this system will be the largest lithium-ion battery 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.” The next largest battery of this kind is 30 megawatts, Musk said in interview conducted with the Australian Broadcasting Corporation.

This isn’t Tesla’s first solar energy rodeo

That December timeline means that once the grid interconnection agreement is signed some time before the fall, Tesla will have 100 days to complete the project or the company might be on the hook for $50 million or more in installation costs, according to ABC.

Of course, the company has made substantial progress on the utility front since the Powerwall and Powerpack’s introduction two years ago. Tesla now supplies energy to the Hawaiian island of Kauai using a large solar energy plant running on the very same Powerpack technology. Medium-sized businesses are also turning to Tesla tech for energy storage, including the Sierra Nevada Brewing Co., while the city of Los Angeles now uses a Powerpack energy storage facility Tesla built into Southern California Edison’s Mira Loma substation in Ontario, California to power 15,000 homes.

So while the South Australia project may be an ambitious one due to Musk’s self-imposed timetable, Tesla has built itself an impressive resume that suggests the 100-day goal won’t be an issue — if all goes according to plan.

Correction: A previous version of this story misidentified the news organization that interviewed Musk. It is the Australian Broadcasting Corporation, not the American Broadcasting Company.