Rio Tinto is scoping out options for up to 4 gigawatts of solar and wind power to supply its Queensland aluminium assets, after soliciting for proposals last June.

In December, the company commissioned a 34 megawatt solar power plant for its Gudai-Darri iron ore mine.

It also pledged $600 million for two 100 MW solar power facilities and a 200 MWh on-grid battery storage plant in the Pilbara iron-ore region, which will be built by 2026.

This forms part of a $3 billion planned investment program to power its Pilbara operations with 1 gigawatt of green energy this decade.

Rio Tinto’s head of technology and development, Mark Davies, told investors in November that it made sense for the company to develop its own renewables in the Pilbara, “as we own much of the infrastructure and operate the grid as part of our integrated operations”.

But elsewhere the company might go for power purchase agreements because “other investors focused on renewables can develop large solutions at a more attractive cost of capital, offering us real operating cost savings”.

Rio Tinto said it was still discussing the 2026 phase-one Pilbara plan, which will involve about 225,000 solar panels, with state and local governments and the traditional landowners.

#"It’s not that easy"

CEO Mr Stausholm raised some issues however, saying Rio Tinto’s effort to shift to large-scale renewable energy sources at its Australian aluminium smelters was “not that easy, and it actually takes a lot of time”.

“People say, ‘Oh Australia, perfect, lots of sun, lots of space’. It’s not that easy,” he said.

“You actually first have to acquire the land, you have to get working with Indigenous people, you have to go through the cultural clearance of sites, etcetera.

“We’re used to big sites in mining, but quite frankly mining sites are small compared to the scale of these parks; and the world has not really done this at scale yet.

“That’s why I think sometimes we’re fooling ourselves a little bit on the timeline. It’s going to take time.”

Mr Stausholm was asked whether governments should try to cut red and green tape to get mining and green energy projects onstream more quickly. His response was cautious.

“We cannot compromise on other things. You’ve got to bring along your local communities, Indigenous populations. It takes the time it takes,” he said.

“There is something about bureaucratic procedure and permitting you can break down. But the whole process of environmental impact assessment is a proven thing, it works well. Obviously, we should try to speed it up.”

Many embodied CO2 studies rely on outdated data which does not acknowledge the constant greening of the supply chain. 1/3 of Gudai-Darri iron ore mine's energy needs for example is met from solar energy. It is likely that the benefits of moving to renewable energy will compound much more rapidly than anticipated.