The path ahead for decarbonising our mines

Last updated: 29 May 2025

Jessica, our Senior Manager of Diesel Transition Program, spoke with attendees at The Decarbonised Mine: The 9th annual Energy and Mines Australia Summit, about how to operationalise mine decarbonisation.

Here are some of the key insights from her discussion.

Progress on the mining industry’s decarbonisation efforts

“We are making solid progress towards our targets. Our emissions are now 14% below baseline levels and we’ve delivered 5 million tonnes (Mt) of operational emissions abatement since we set our targets,” Jessica said.

“We are largely on track for 50% operational emissions reduction by 2030 with a pipeline of investments in place.

“Our single largest lever – accounting for around one quarter of our emissions – is at the Boyne and Tomago aluminium smelters in Queensland and New South Wales in Australia. Repowering these operations remains a core priority to achieve the 2030 target.

“The first 50% of emissions reductions is the lowest cost and lowest risk portion of our emissions, largely related to renewable power. We’re now entering into the more challenging areas of our portfolio, this is mineral processing and diesel transition.

“In these areas, the key challenge is that the technology is simply not ready to be deployed in an operational setting in a safe and reliable way, and so our investments are focussed on maturing this technology.

“Electrification is also not technically or financially feasible at all mining operations today, or for all types of equipment. It’s well suited to our greenfield applications where we have large fleets, but less so to brownfield operations with smaller fleets, shorter mine life or other operational complexities.

“That’s why we developing complementary pathways that include the use of renewable diesel to more immediately reduce diesel-sourced emissions.”

The role of diesel transition in decarbonising mining and lessons learned

“Our diesel transition strategy is twofold – electrification and renewable diesel. This dual strategy enables us to optimise how we displace diesel, recognising that electrification won’t be viable at all of our operations,” she said.

“One of the most crucial lessons we've learned is maximising the value of demonstrations. These are critical, especially in areas where technology maturity is low, to build confidence before full-scale deployment. For example, we're currently demonstrating an electrification system at Oyu Tolgoi in Mongolia, involving 8 battery electric trucks and a battery swapping station. This integrated approach ensures we test all elements comprehensively.

“On the renewable diesel front, we've had success in procuring renewable diesel where it’s available and stimulating the market where it’s not. In North America, our Kennecott and Boron operations have fully transitioned to renewable diesel. However, in Australia, the market is not as mature. To address this, we're investing in self-generation of renewable diesel, like our pongamia seed farming trial near Townsville in Queensland. This collaboration with Midway Limited highlights the importance of partnerships and strategic investments in new areas to stimulate industry growth.”

Balancing the need for production with the urgency of funding energy transition

“Our projects typically enhance the value of our business by reducing our exposure to volatile fossil fuel prices and higher carbon costs,” Jessica said.

“Our decarbonisation investment process is rigorous and aims to secure structural, long-term, cost-efficient solutions. But this balance is a real challenge where the technology is not mature and our understanding of value and risk is not as robust.

“We prioritise areas where there is a potential business case – where our objectives of value creation and emissions reduction align. For example, electrification offers potential long-term value due to the fundamental energy efficiency between diesel and electric engines.

“Then, we can start at a small scale through pilots and demonstrations, which allows us to build confidence early and de-risk the solution at a low cost.”

Electrifying more mines depends on battery density

“The biggest step change development that will drive greater deployment of electrification is in battery density,” she said.

“Put simply, the more dense a battery is, the more energy it can store, the heavier the duty cycles it can perform, and the longer its life. This means we can apply electrification to more mines, reducing operational complexity, making our operations safer and increasing the value of electrification investments.”