The world’s largest renewables project has been proposed in Western Australia, covering an area half the size of Belgium.

The Western Green Energy Hub would include as much as 50 gigawatts of wind and solar over more than 15,000 square kilometers (5,800 square miles), according to the international group that’s planning the project. It could cost as much as A$100 billion ($75 billion), with first production from the beginning of the next decade.

Two members of the consortium behind the plan, InterContinental Energy and CWP Global, are also involved in the Asian Renewable Energy Hub, another contender for the world’s largest green power site that was last month rejected by Australia’s environment minister. Hong Kong-based InterContinental is also seeking to develop a green hydrogen project in Oman.

The new Australia project would produce as much as 3.5 million tons of green hydrogen or 20 million tons of green ammonia per year for export and domestic use. A unit of Mirning Traditional Lands Aboriginal Corp., which represents the area’s indigenous landowners, is the third member of the group proposing the development.

Aside from environmental approvals, the main challenge for a massive project like the Western Green Energy Hub is finding buyers, according to Martin Tengler, BloombergNEF’s lead hydrogen analyst. While it’s too early to tell, most of the hydrogen from the hub will likely be exported by ship, which will become quite costly compared with local output in even the most expensive hydrogen producers such as Japan and South Korea, he said.

“The question will be how much demand Japan and Korea will have by then and how much they can supply domestically,” Tengler said.

The hub would be built in phases and take advantage of high levels of wind and solar energy in Western Australia, the group proposing the project said.

“Green fuels produced at the site will meet massive future demand from multiple sectors, including in co-firing in power generation, the shipping sector, heavy industry such as steel, chemicals and mining, as well as the aviation sector,” they said in their statement.

The $20 billion Sun Cable project that’s set to build a 14-gigawatt solar farm as well as an energy storage facility of 33 gigawatt-hours in Australia’s Northern Territory is currently the world’s largest planned renewable project, according to data from BloombergNEF. That project is expected to reach financial close in October 2023.

“The Western Green Energy Hub is a truly massive proposal that would see WA home to one of the world’s largest renewable energy projects,” Western Australia Hydrogen Industry Minister Alannah MacTiernan said in a statement. “Our State is perfectly positioned to lead the global renewable hydrogen industry, delivering a strong economic future for WA and becoming a major contributor to global decarbonisation.”