The company, which is Queensland’s biggest energy consumer, wants a massive 4000 megawatts of wind, solar and storage in central or southern Queensland and has called on the market for proposals.

The plan would cost several billion dollars. The state’s biggest wind scheme, the McIntyre wind farm project currently under development, is expected to cost $2 billion and deliver 1026 megawatts of capacity.

The scheme would deliver energy to the Gladstone assets by 2030 and was part of Rio’s ambitions to halve its C02 emissions.

The company has three major facilities in Gladstone: the Boyne Smelter, the Yarwun alumina refinery and the Queensland Alumina Refinery and they needed 1140 megawatts of reliable power which Rio said equated to 4000 megawatts of quality wind or solar power with firming (storage).

Last year the company signed a statement of co-operation with the State Government to underwrite “long term green offtake” for its assets.

Rio’s aluminium chief executive Ivan Vella said the company had an important role to play in driving the development of competitive renewables.

“It’s early in the process, but this is an important step towards meeting both our group climate change target of halving our emissions by the end of the decade and our commitment to net zero emissions by 2050,” he said.

The Australian Conservation Foundation’s Gladstone campaigner Jaclyn McCosker said it was significant that the state’s biggest energy consumer was showing that it was serious about using large-scale wind and solar to power its energy-hungry aluminium refineries and smelters.

“ACF welcomes this announcement and congratulates Rio Tinto for progressing its goal to cut emissions by 50 per cent by 2030,” she said.

“Coupled with the news that Australia’s energy ministers have agreed to come up with a national transition plan to phase out fossil fuels, this marks a significant moment in Australian action to tackle climate change.

“Queensland can and should be a renewable energy superpower and central Queensland has all the ingredients to thrive in a low carbon world.

“While this private sector announcement is positive, we also need more action from the Queensland Government to manage the orderly closure of coal-fired power stations and facilitate a just transition plan for workers, their families and communities.

“With a federal target to cut climate pollution by 43 per cent by 2030 and Rio Tinto taking the lead to repower some of Queensland’s most high-emitting projects, the Palaszczuk Government’s 30 per cent by 2030 target is now untenable.”

“As a custodian of the Great Barrier Reef, the Wet Tropics and the Gondwana rainforests, we urge the Queensland Government to lift its target and ambition on climate action.”