Displacing diesel from a mining fleet can remove up to 40% of a mine site’s emissions. Richard Fenton, Vice President, Global Distributed Energy Systems, Worley, shares how miners can break their reliance on diesel.
In the past 18 months, some of the world’s largest mining companies have publicised their commitments to reach net-zero carbon emissions by 2050. But as some of the most carbon-intensive businesses in the world, they cannot simply build or buy renewable energy. They need to reduce, and ultimately eliminate, fossil fuels such as diesel and natural gas from their operations.
Breaking the reliance on diesel
According to a report by the Australian Renewable Energy Agency, the Australian mining sector uses 10% of the country’s energy use and consumes approximately 5 billion l/y of diesel. For a large opencast mine, this could amount to AUS$1 billion of a project’s annual operating expenditure across their mining portfolio. With the indicators that 50% of the energy used in the Australian energy sector is derived from diesel use, it is clear why the focus of many global mining companies is seeking alternatives to diesel to reduce operating costs and corporate emissions. The remaining 39% and 11% are derived from electricity and other (fugitive, land use, etc.).
Diesel is expensive and counterintuitive to the mining industry’s goal to be reach net zero.
Ultimately, miners will need to reduce diesel consumption to achieve their scope 1 and scope 2 emissions targets.
But how do miners break their reliance on the fuel efficiently and with little disruption? There’s a roadmap – but it is complex.
Three steps to displacing diesel
Looking at decarbonisation as one project is intimidating – taking a staged approach can help to ease this. Worley’s three horizons model takes miners through a logical transition of fuel reduction, replacement, and elimination. Each horizon is interconnected. What is decided in horizon one sets the foundation for successful decarbonisation over the following decades.
Horizon one: reduce diesel use
Horizon one applies careful optioneering, research, and development to build the foundation for emerging technologies as they become viable – the key is to concentrate on a no regrets policy. Between 2021 and 2030, miners need to consider all equipment in use against current technology options such as fleet electrification and using hydrogen fuel cells. Equipment can make up 40% of a mine’s total diesel consumption so it is a compelling first step.
As an example, haul trucks use around four times as much fuel travelling uphill than they do on a flat surface. Instead of using diesel, trolley assist sets up trucks like a tram, with a pantograph connecting to an overhead container system as the truck travels up an incline. It then uses electricity to power the rear wheels of the truck while the diesel engine sits idle. This reduces diesel use by approximately 90% while driving up the ramp.
Battery storage technology is also advancing, particularly when it comes to electric vehicles. But there is still work to do for miners because they are dealing with a 290-t truck rather than a 2-t car, without the benefit of carbon fibre and aerodynamics.
Hydrogen fuel cell vehicles are also being explored, with some miners spending a considerable amount on research and development as questions remain on whether hydrogen can scale to be used in mining in the 2040s.
Horizon two: avoid or replace diesel
Horizon two, between 2030 – 2040, expands on the technology implemented in horizon one and looks for other options as the technology advances.
As batteries improve during horizon one, batteries could be recharged through the trolley assist electrical system – bringing horizons one and two together.
When it comes to hydrogen powered trucks, haul truck manufacturers and technology providers are being challenged to scale up a 1 MW hour battery in a truck that uses a combination of hydrogen and battery energy. Anglo American are set to commence trials into this technology in a platinum mine in South Africa. And if successful, there are plans to extend this further.
Miners also need to consider equipment manufacturers outside the typical original equipment manufacturers. This is to take advantage of new and emerging technologies such as 100% hydrogen powered excavators. While they are not at the size and scale needed for mining, it is up to the industry to invest in research and development to reach the scale it needs.
Horizon three: eliminate diesel
Between 2040 and 2050, miners should be able to eliminate diesel from their mining and transport fleet if they follow horizon one and two. This includes in-pit mining equipment as well as long distance rail haulage from pit to port.
Horizon three presents opportunities for miners to start using inductive technology – or wireless charging. It is currently being explored in the Formula E racing circuit where safety cars charge while stationary.
The manufacturers of the Dynamic Electric Vehicle Charging (DEVC) system have also built and tested a system that can charge a vehicle while traveling at 100 km/h with 20 kW rate of charging. Similar systems are also used in passenger bus services. For example, a fleet of electric buses in Washington use induction charging that is built into the road surface and at bus stops.
This technology is currently in its infancy, but it is a research and development opportunity that could help end diesel use in mine sites altogether.
Every litre of diesel counts in the race to net zero
The vision for achieving net zero needs to be set today but like any momentous change, it will take a series of well-planned steps to reach the end goal. The next few years are critical, and miners will need to set staged horizons to pave a clear path toward a diesel-free future.
Read the article online at: https://www.globalminingreview.com/special-reports/30032021/why-displacing-diesel-is-crucial-for-miners-emission-targets/