With traditional mining truck fleets contributing up to 80 per cent of total emissions in open pit mines, it is crucial the sector finds an optimal decarbonisation pathway for its fleets.
Since miners are responsible for approximately 3 per cent of greenhouse gas (GHG) emissions globally, they have an important role to play in limiting emissions.
Operators need to confront and address the multifaceted challenges posed by climate change – including the increased frequency and severity of extreme weather events that damage operational infrastructure.
Research published in the Journal of Automation and Intelligence proposes a decarbonisation pathway for mining truck fleets encompassing renewables, battery electric trucks and hydrogen fuel cell trucks, and forestation.
It suggests replacing current diesel-powered trucks with battery trucks and deploying renewable infrastructure to support charging as soon as possible if budgets permit, with hydrogen trucks expected to become more cost-effective after 2044.
The research notes that forestation is the most cost-effective way among carbon capture technologies, while carbon trading prices enable the truck fleet to achieve decarbonisation solely through carbon trading, without necessitating investment in specific carbon capture technologies.
“The carbon trading system builds a ready market for carbon permits helping companies to trade so that they can meet their allocated emission limit,” the research said.
“At the end of each year, each company is required to ensure they have enough carbon permits to cover their emissions.
“Companies have the flexibility to purchase additional carbon permits from the market.
Those companies with carbon permits left over can sell them or save them for future use.”
Mitigating climate change, the paper suggested, was an issue that would face all players in the modern mining game as, traditionally at least, extractive operations intensified pollution as well as caused acid mine drainage, soil contamination and the disruption of ecological systems.
They also exacerbated concerns about health hazards within their local communities.
“The challenges posed by climate change, as well as increasing stress from government, investors and the public force mining companies to transition to low-carbon and sustainable production patterns,” the paper said.
“The mining transportation fleet is one of the primary sources of on-site GHG emissions of the mining industry, which can account for up to 30 per cent of on-site GHG emissions or up to 80 per cent if the mine is without refinery facilities.
“It is reported that mineral loading and hauling operations account for 41.4 per cent of total energy consumption and contribute 37.1 per cent of GHG emissions during coal mineral processing. Therefore, decarbonising the transportation system is critical for the decarbonisation of the whole mining production process.”
The starting point for vehicle decarbonisation, the paper noted, involves the current fleet configurations and the corresponding energy consumption and carbon emissions, which could be obtained through carbon accounting.
Meanwhile, the task ends with a desired fleet configuration that delivers significantly reduced carbon emissions.
The enhancement of truck energy efficiency involves the improvement of aerodynamics, engine efficiency, transmission and the drive train.
For the logistical system, it is typically advanced by optimising transportation routes, waiting times and fleet sizes (therefore reducing GHG emissions per unit of production).
Fully enhancing logistical systems, the paper said, was a cost-effective approach to achieving decarbonisation targets in the short term.
Furthermore, incorporating smart dispatching into an existing fleet could yield a 10 to 30 per cent reduction in emissions, with the associated adoption cost equating to 47 per cent of fleet electrification costs.
Nevertheless, it is imperative to acknowledge that while improvements in the energy efficiency of trucks and logistical systems could effectively mitigate emissions from fleets, achieving a fully zero-emission target remains “elusive”.
“For this purpose, alternative power sources for trucks are developed rapidly, whereas battery electric trucks (BETs) and hydrogen fuel cell trucks are regarded as primary alternatives,” the paper said.
“If BETs are charged by the grid comprising about 10 per cent coal, reductions on fuel consumption-related emissions and the lifecycle cost surpass 70 per cent and 63 per cent respectively.”
