The US$245 million Tanami power project was completed on time.
The project included the installation of two power stations, built and operated by Zenith Energy, a 66kV interconnected power line, and a 450km natural gas pipeline, which was built and will be maintained by Australian Gas Infrastructure Group.
Newmont will make annual cash lease payments over 10 years starting this year.
The project will lower the mine's power costs and reduce carbon emissions by around 20%.
The project is expected to generate net cash savings of $34 per ounce from 2019 to 2023, delivering an internal rate of return of greater than 50%.
"In addition to lowering costs and carbon emissions, the completed Tanami power project will pave the way to further extend the life of the operation," Newmont CEO Gary Goldberg said.
Newmont completed the $125 million Tanami 1 expansion in late 2017 and has been studying a further expansion, with a decision due in the second half of this year, which would extend the mine's life beyond 2028.
Tanami was Australia's fourth-largest gold producer in 2018, with gold output of 496,000 ounces, and is Australia's second-largest underground gold mine.
"Consistent execution and delivery remain the hallmark of our ability to generate free cashflow and create long-term value for our shareholders and other stakeholders," Goldberg said.
"Completion of the project coincides with Tanami pouring its 10 millionth ounce of gold on the back of record production of 500,000oz last year.
"This achievement is a testament to the skill of our team as well as our valued partnership with the Warlpiri people, the Traditional Owners of the land."