Billionaire Mike Cannon-Brookes has claimed control of the controversial Sun Cable solar export project, winning a bidding war after falling out with his former project partner, Andrew Forrest.

The pair, who are among Australia's richest men, have been in a closed door bidding process to wrest control of what's been promoted as "the world's largest solar energy infrastructure network". 

Andrew Forrest's entity Squadron Energy said it made an initial offer for the Northern Territory project, but then withdrew from the final bidding process. 

Sun Cable's administrators said the company had now entered into a sale agreement with a consortium connected to Mr Cannon-Brookes's Grok Ventures.

The consortium also includes infrastructure investor Quinbrook.

Under their control, the project will pursue its original goal of exporting solar power from the outback of Australia to the island nation of Singapore. 

Mr Forrest said his company was "unconvinced of the commercial viability" of sending the power to Asia.

But, in a statement, Mr Cannon-Brookes said the outcome was "a big step in the right direction":

"We've always believed in the possibilities Sun Cable presents in exporting our boundless sunshine, and what it could mean for Australia. It's time to stretch our country's ambition. We need to take big swings if we are going to be a renewable energy superpower. So swing we will."

A joint statement from Grok and Quinbrook said Sun Cable had "the potential to be a nation-building project for Australia, generating and transmitting critical clean energy to Singapore and [supplying] renewable energy to new Northern Territory industries".

Sun Cable was put up for sale earlier this year, after a split between the two men, who were its biggest backers when it required an initial investment of $30 billion. 

The men had different visions over what to do with the 20-gigawatts of power the solar farm was expected to generate in the middle of the outback.

On Friday, Mr Forrest congratulated Mr Cannon-Brookes, and issued a statement saying:

"While Squadron Energy did not participate in the final binding bid process for Sun Cable, we are delighted that other investors like Grok are playing a role in tackling global warming, by replacing fossil fuel investment with green energy projects.

"Squadron decided the capital allocation did not align with Squadron's strategic goals, as we are already working to deliver 30 per cent of the renewable energy required to meet the federal government's target of 82% renewables by 2030 and want to bring new green electrons into the grid as soon as possible."

Harnessing the sun to help power Singapore

Sun Cable was formed in 2018 by a team of people based in Singapore and Australia, including current chief executive David Griffin.

In 2019, it revealed a plan to transform Australia, one of the world's biggest miners, into an exporter of renewable energy.

Sun Cable wanted to build a solar farm in outback Northern Territory, which would be large enough to be seen from space, with much of the renewable power it generated to be sent to Singapore.

To do this, Sun Cable wanted to install a large battery network and run a 4,200 kilometre undersea transmission line from a spot near Darwin to the gas-dependent island nation.

Initially, Mr Cannon-Brookes and Mr Forrest appeared to be united on the project's goal to export solar power to Singapore. But the partnership fractured earlier this year.

In a statement early this month, the Energy Market Authority of Singapore (EMA) told ABC News it was in "discussions" with Sun Cable and couldn't discuss them as they were commercially sensitive.

"No agreement has been signed with Sun Cable," a spokesperson said. "And EMA has not made any financial contribution to the project."

Final environmental approvals for the solar farm also haven't been given, and traditional owners need to be consulted about the 12,000 hectares of panels to be erected.

Why did two of Australia's richest men fall out over Sun Cable?

Earlier this year, Mr Forrest's private investment arm Squadron indicated it no longer supported Sun Cable's goal to export solar to Singapore, and would prefer to use the energy it generated for local projects, such as making hydrogen.

Mr Forrest has been a vocal proponent of hydrogen, including for generating so-called green steel.

After the split emerged, Sun Cable was put into administration and up for sale.

As well as Mr Cannon-Brookes's Grok Ventures and Mr Forrest's Squadron, the ABC understands there were several other entities bidding for control of the project.

Final bids closed on May 23.

What does this mean for local supply of solar?

Much of the focus on Sun Cable to date has been on its plan to export power to Singapore to supply up to 15 per cent of the island nation's energy needs.

However, it also planned to supply a chunk of solar energy to the Northern Territory, provisionally reported as around 800 megawatts.

Critical minerals company Tivan signed a non-binding deal with Sun Cable earlier this year, while it was still in administration, to take some of its solar energy in Darwin.

Tivan wants to mine critical minerals in Australia and process some of them at a development precinct proposed by the NT Government at a site in Middle Arm.

Tivan's executive chair Grant Wilson said it hoped to take 200-300MW of solar energy from Sun Cable to power its proposed Middle Arm site.

"We're happy to work with either party," Mr Wilson said ahead of the announcement, but added the deal may need to be re-negotiated if there was a change of management or board structure.

Mr Wilson said if Friday's decision meant they could not access Sun Cable's solar power, they would seek to get renewable energy elsewhere to offset production, and even floated the idea of accessing electricity from beleaguered NT solar farms not yet connected to the grid.

"It's a decision for Sun Cable. We just want to see the project go ahead," he said.

"Because Sun Cable is such a mega project, they're able to offer the lowest price [for the solar] because of the economies of scale."