Rio Tinto has transitioned its entire fleet of heavy mining equipment at the Kennecott copper mine in Utah from conventional diesel to renewable diesel, making it one of the lowest carbon-emitting copper producers in the U.S. Kennecott’s 97 haul trucks, along with heavy machinery at the concentrator, smelter, refinery, and tailings areas, now run on renewable diesel sourced domestically. This switch is expected to cut the mine’s Scope 1 emissions by 450,000 tonnes, equivalent to the emissions from 107,000 cars annually. Additionally, PM2.5 tailpipe emissions from the haul trucks are reduced by 40%, a reduction on par with 2.3 billion miles of light vehicle travel per year.
Kennecott’s low carbon footprint reflects initiatives such as closing a coal-fired power plant, installing a 5-megawatt solar farm, deploying battery electric vehicles underground, and the transition to renewable diesel. As a result, the operation has reduced its overall carbon footprint by over 80% since 2018.
Celebrating the achievement at an on-site event with Utah Governor Spencer J. Cox, Rio Tinto Copper COO Clayton Walker stated, “Transitioning to renewable diesel marks a major milestone toward our decarbonization goals at Kennecott, where emissions are now down 80% thanks to recent initiatives. We are committed to environmental stewardship and continuously finding better ways to supply materials essential for the energy transition.”
This move also supports low-carbon fuel availability in Utah. HF Sinclair, in partnership with Kennecott, has dedicated two tanks with a combined capacity of 36,000 barrels (1.5 million gallons) to renewable diesel for the mine.
HF Sinclair’s Executive VP of Commercial, Steven Ledbetter, said, “We’re proud to support Rio Tinto’s sustainability journey by supplying low-carbon fuel from our facilities. It’s exciting to see Kennecott fully implement renewable diesel, which could benefit other industries adapting to new energy needs.”
In 2023, Kennecott conducted a successful trial comparing renewable diesel performance to conventional diesel across two haul trucks. Results showed comparable performance, consistent with findings from Rio Tinto’s Boron mine in California, which also completed its transition to renewable diesel in May 2023.
This transition at Kennecott, alongside the Boron mine, replaces 11% of Rio Tinto’s global fossil diesel consumption. The company aims to reduce its Scope 1 and 2 emissions by 50% by 2030 and achieve net zero by 2050.
The renewable diesel in use is composed of 90% soybean oil, with the remainder from animal fat and used cooking oil.
