Tesla is making serious headway on its massive battery project in South Australia.

On Friday, Tesla and SpaceX CEO Elon Musk said that the company was halfway done building the battery bank that will become the world's biggest battery once it's complete. Musk made the announcement at a party overlooking the project's construction, ABC News Australia reported.

Tesla is building the 129-MWh battery with French energy company Neoen. The battery will be draw energy from Neoen's Hornsdale wind farm that's 142 miles north of Adelaide. The electricity will be delivered to South Australians during peak grid times to reduce the number of blackouts in the area, which are frequent in summer months.

"The system is a big battery, a battery big enough to power 50,000 houses -- the biggest in the world," Neoen global COO Romain Desrousseaux previously told Business Insider.

Tesla is building the bank using its commercial battery, the Powerpack, which is being manufactured at the company's Gigafactory in Sparks, Nevada. 

Musk said in March that it will cost just over $32 million to build the battery, before taxes and labor. He said the company will build the battery in 100 days, a tight timeline that began Friday after the Australian Energy Market Operator officially approved the project.

Panasonic usually manufactures the battery cells for Tesla's Powerpacks, but Tesla chose Samsung as the supplier for this particular project, Nikkei Asian Review reported. Samsung was reportedly better situated to supply the cells within Tesla's 100-day deadline. 

This post originally appeared on Business Insider.