MELBOURNE (REUTERS) - Atlassian Corp co-founder Mike Cannon-Brookes has pledged to help fund an ambitious A$20 billion (S$18.68 billion) project to supply solar power from northern Australia to Singapore by a subsea cable, an Australian newspaper reported on Wednesday (Sept 25).

The plan unveiled earlier this year by Singapore-based firm Sun Cable is to build the world's largest solar farm on a 15,000 hectare site in Tennant Creek in the Northern Territory, which could export 3 gigawatts of power via a 3,800-kilometre cable to Singapore. This represents approximately a fifth of Singapore's electricity supply, said Sun Cable on its website.

Cannon-Brookes did not specify how much of the "insane" project his family fund, Grok, planned to finance but said he was being joined by other Australian entrepreneurs and an announcement was likely before the end of the year.

"I'm backing it, we're going to make it work, I'm going to build a wire," the Australian Financial Review (AFR) quoted Cannon-Brookes saying in an interview on the sidelines of the United Nations Climate Action Summit in New York.

Sun Cable, which has not detailed its funding plans for the project, did not immediately respond to a request for comment.

The project, which has been given major project status by the Northern Territory to help fast-track approvals, would include battery storage.

Cannon-Brookes, who has been a vocal advocate for renewable energy in Australia, said the project could also expand to produce hydrogen fuel, which could be exported to markets such as Japan.

"This will be absolutely great - with world-leading engineering required all up and down. But we can do it," he was quoted saying in the AFR.

Cannon-Brookes, 39, became a billionaire through his stake in the software firm Atlassian, which he co-founded with Scott Farquhar.

He made his name in the power sector in 2016 when he challenged Tesla Inc's Elon Musk via Twitter to build the world's biggest battery in 100 days to help prevent blackouts in South Australia, the country's most wind power reliant state.

The bet was dismissed as outrageous at the time, but Tesla built the battery on time and the project has since proven to be profitable in helping manage power supply on South Australia's shaky grid.