Digging to zero? Inside the race to decarbonise mining

The resources needed to decarbonise the world economy lie buried beneath the Earth. There is no alternative to digging them out if the energy transition is to take place. Without mining, there will be no silicon for solar panels, no steel for wind turbines, no lithium, cobalt or nickel for electric vehicles.
However mining itself accounts for 4-7% of global emissions. While an estimated 75-85% of the sector’s emissions come from methane released from coal mines , this problem is expected to abate over the next 25 years as the world gets on course for net-zero.
That’s why the focus is on decarbonising other forms of mining that are vital to the energy transition, where demand is rapidly rising. The International Energy Agency projects that reaching net-zero will mean a 50% rise in demand for copper by 2040, along with a doubling of nickel and cobalt demand, and an eightfold increase in demand for lithium.
As the mining industry looks to confront the challenge of producing more while emitting less, the company that appears to be front of the pack is Australian iron ore giant Fortescue.
Rather than relying on carbon offsets to compensate for its residual emissions (Fortescue’s website describes carbon offsets as a “scam”), the company decided in 2022 to aim instead for “real zero”.
Its billionaire chairman, Andrew Forrest, is a ferocious critic of “net-zero”; in April, he told the Innovation Zero conference in London that “the word ‘net’ is killing us”, demanding instead that companies find ways to stop burning fossil fuels.
As such, Fortescue has committed to eliminating terrestrial Scope 1 and 2 emissions from its vast iron ore mining operations across an 87,000 square km area of the Pilbara region of Western Australia. And it aims to hit this milestone not in 2050, but in 2030.
“We said, ‘Okay, let’s pick a top-down target of 2030, backed by real climate science that is now undeniable, and put that mark in the sand and set that as an industry target’,” says Dino Otranto, CEO of Fortescue Metals. “We wanted to be the exemplar and demonstrate it’s possible. But that meant we had to carry out that plan in a very unconventional way.”
The first task, he says, has been to convert Fortescue’s mining operations from diesel and, to a lesser extent, gas. It aims to deploy 2-3 gigawatts (GW) of solar and wind power, backed up by enormous battery storage systems.
The “biggest enabler” in making this viable, says Otranto, has been the steep decline in the cost of solar panels and batteries in recent years. “The cost of renewable infrastructure is now significantly cheaper than its gas equivalent.”
Switching to renewables is a huge undertaking that also involves the build-out of an extensive transmission network to bring power to where it is needed across the Pilbara region. But the really unconventional element of Fortescue’s $6.2 billion decarbonisation plan is its investment in its own proprietary technology.
The company has developed several designs for the trains used to haul iron ore along the 760km rail network that links its Pilbara mines to Port Hedland on the coast of Western Australia, from where it is shipped to global markets.
One of these designs seeks to harness gravitational energy as trains descend 400 metres in altitude on their journey from the mine sites to the coast. Currently, diesel trains apply their brakes on the descent “and you get rid of all that energy through huge toasters and resistors”, says Otranto. “It’s very, very inefficient.”
Fortescue has dealt with this problem by developing motors that harvest energy during the descent, then release the charge when trains make their way back up to the mine.
This regenerating battery technology is just one of the technical innovations that Fortescue has developed within impressively short timelines. It is also using ammonia-powered trains, while its latest prototype for a green electric design went from “nothing to production-ready in nine months”, says Otranto.
“I think sometimes people misunderstand what we really are pulling off here, and that’s why so many people just doubt that we’re actually doing it,” says Otranto. “Well, I open the door to competition, suppliers: I want them to see that it is possible. This is the right thing to do.”
Fortescue’s ambitions are unmatched within the industry, but it is far from the only mining company making progress towards reducing emissions. Across the world, many mine sites – which are often in remote areas, disconnected from national electricity grids – are finding that it makes financial sense to install solar power or other forms of renewable energy as an alternative to diesel generators.
In the Democratic Republic of Congo, for example, the Kamoa Copper mine, the largest copper mining complex in Africa, announced in early April that it will procure baseload power from a solar and storage system to be built and operated by renewable energy developer CrossBoundary Energy. Kamoa will not incur an upfront cost, instead paying for the electricity it receives over the course of its contract with CrossBoundary.
The deal is set to reduce the mine’s carbon emissions by around 78,750 tonnes per year. “Where this project is exceptionally exciting is that this is a baseload renewable energy solution,” says Matthew Tilleard, managing partner at CrossBoundary Energy. The baseload characteristic is achieved by building a system that he concedes is “in some ways massively oversized”.
The company will build a 222 megawatt (MW) solar array and a massive battery system to guarantee 30 MW of baseload power. “But what that means is we’re delivering reliable power, baseload power, that’s completely carbon-free at a price that is cheaper than diesel.”
Indeed, it is the economics of off-grid renewable energy that make these systems attractive to mining companies. “You don’t have to believe in climate change,” says Tilleard. “This is cheaper.”
Technology is also advancing around mining trucks. There are around 28,000 of these gargantuan and highly specialised vehicles operating around the world, emitting around 69 million tonnes of CO2 equivalent.
The International Council on Mining and Metals, the industry organisation that represents 24 of the world’s largest mining companies, is running an initiative to find ways to reduce emissions from trucks. Mining companies are partnering with equipment manufacturers such as Caterpillar, Komatsu and Sandvik in the initiative.
“Since we started that programme in 2018, we have seen significant progress,” says Bryony Clear Hill, the ICMM’s director of innovation. “We’re now estimating that we’ll have zero-emission vehicles at scale by 2030, which is a full 10 years ahead of the best estimates when we started the programme.”
Clear Hill adds that there will be no “one size fits all” solution to decarbonising mining vehicles. Battery electric technology does appear to have the most momentum, however, with several prototypes already being tested.
Despite the visible progress being made around the world, the pace of decarbonisation is highly uneven across the industry. This is partly because every mine site is different: the feasibility of installing zero-emissions solutions such as solar or wind power depends on highly localised conditions, as well as the availability of land.
Much also depends on government support. A mine that is grid-connected will not be able to decarbonise if the grid is dependent on fossil fuel power, for example. Government policies to enable mining companies to sign power-purchase agreements with private electricity suppliers are also key.
“There’s this broader ecosystem of enablers that needs to be in place to support mining, to be able to reduce at scale, at pace, so that we can be able to supply those critical minerals,” says Hayley Zipp, director of the environment programme at the ICCM.
“If you’ve got weak access to power-purchasing agreements and independent power producers, that’s really going to slow you down.”
Gregoire Bellois is a senior policy advisor at the Intergovernmental Forum on Mining, Minerals, Metals and Sustainable Development. He says that mining companies display varying levels of commitment around decarbonisation. Some larger companies are making “real progress”, he says. Others achieve decarbonisation only “on paper”, simply by divesting their highest-emitting mines.
Most Chinese companies are “really, very early in this process”, Bellois adds. Chinese firms are increasingly dominant in certain strategic mineral supply chains; Benchmark Mineral Intelligence estimates that Chinese companies will control 46% of the world’s cobalt supply by 2030. Though Bellois says some have shown interest in reducing their carbon footprint, “currently, they don’t see why they should do it. They have no requirement to do it. So, they don’t do it.”
One development that could have worldwide effects is the European Union’s proposed Carbon Border Adjustment Mechanism. If implemented, CBAM would impose a levy on carbon-intensive companies that export into the EU market. “In theory, it’s a really good tool,” says Bellois. But he warns there could be “perverse effects”, in that many producers will effectively be excluded from the European market, and will instead simply redirect exports towards customers in China.
While Bellois believes some mining companies can decarbonise, he is sceptical that the entire industry can make it even to “net” zero by 2050, let alone the “real” zero championed by Fortescue. Yet, given the significant acceleration in the production of many types of minerals, action is vital.
“We expect to mine in the next 30 years more than what we mined over the whole history of humanity,” says Bellois. “Every effort to try to limit the amount of what is emitted would be a net win.”
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