The company will spend the funds to build two 100MW solar power facilities, as well as 200MWh for on-grid battery storage in the Pilbara by 2026.
This will be an addition to recently installed solar power of 34MW at the newly commissioned Gudai-Darri iron ore mine.
Rio Tinto has received approval for funding for the company's first major stand-alone farm on the Pilbara coast, as well as a 100 MW solar photovoltaic system and associated transmission infrastructure.
The company will begin construction next year, while the project will be commissioned in 2025. Construction will include the installation of approximately 225,000 solar panels which will be built to weather cyclonic conditions in the Pilbara.
Rio Tinto expects final capital approval to be finalised in the June quarter 2023.
These projects are expected to abate approximately 300,000 tonnes of carbon dioxide, equivalent to a 10 percent reduction in total Scope 1 and Scope 2 emissions from the company's iron ore assets in the Pilbara. The estimates are based on 2021 levels of emissions.
Relying on renewable energy will also decrease gas costs by approximately US$55 million on an annual basis, as it will replace an estimated 30 percent of Rio Tinto's current gas consumption in the Pilbara.
"The Pilbara is extremely well-positioned to take advantage of renewable power with land, access to people, and abundant wind and solar resources," Rio Tinto Iron Ore chief executive Simon Trott said.
"Our Pilbara electricity grid is the largest privately-owned grid in Australia, ensuring that we have the initial infrastructure required to enable a transition to renewable energy."
Rio Tinto expects to invest around US$3 billion to install renewable assets in addition to transmission and storage upgrades in the Pilbara. It is targeting the halving of emissions from the Pilbara by 2030.