Countries, industries and individual companies have all been taking serious steps toward the phasing out of conventional diesel and petrol-fuelled vehicles, and these changes are now being seen in the mining industry.
The electrification of mining vehicles will likely gain momentum as mines age, technology advances and mining operations extract ore deeper and deeper into the Earth. According to a projection by IDTechEx, electric mining vehicles mining will be a $9 billion market by 2028, with businesses like Sandvik, Komatsu, and Caterpillar currently working on completely electric equipment.
Diesel engines have long been the industry convention for mining, despite the fact that they are fundamentally inefficient at transforming fuel energy into work. At best, diesel engines for mining have about 45 percent efficiency. Conversely, electric drive trains can hit an energy efficiency of around 90 percent.
There are very good reasons why the diesel engine has been the dominant drive train technology in the mining industry for so long. The working conditions for these vehicles can be very difficult, and the diesel engine is able to tolerate many challenges, including extreme temperatures, heavy vibration, aggressive start/stop cycles, exposure to corrosive substances and harsh pressure washing.
When it comes to emissions alone, reducing the usage of diesel fuel could have considerable cost benefits for the industry: as much as 40 percent of an underground mine’s energy expenditure is invested in massive ventilation systems. However, the initial cost of purchasing an electric vehicle would be about double that of a conventional diesel vehicle. Although this is compensated by reduced long-term fuel and energy costs, the primary costs might be restrictive. Manufacturers are however taking steps to mitigate up-front investment costs. In an effort to increase sales, mining equipment maker Epiroc announced it would lease batteries for its electric vehicles, making the up-front investment only somewhat greater than it would be for a conventional machine.
The spread of electric mining equipment will likely depend not just on the vehicles, but also associated technologies. For instance, advancements in battery technology can lead to a decrease in the price of battery packs for electric mining vehicles.
Regenerative Energy to Power the World’s Biggest Electric Vehicle
Commonly used in mining operations, a standard dumper truck uses between 50,000 and 100,000 liters of diesel each year, based on its usage. It also typically emits between 130 and 270 tonnes of carbon dioxide.
To address these concerns, a partnership between the Switzerland-based Lithium Storage GmbH and Kuhn Schweiz AG announced the successful conversion a Komatsu truck into an electric vehicle powered by regenerative energy and a 700-kWh battery pack, making it the world’s largest electric vehicle.
The regenerative drive technology is a key factor in the use of electric mining vehicles, as it sends otherwise wasted energy from braking and hydraulic pumps to be stored in a battery or supercapacitor. The drive controls the flow of energy and transforms kinetic or potential energy into electric energy. Regenerative drives developed for mining vehicles are leading to superior overall efficiencies through savings in energy usage and ventilation systems.
Dumper trucks are particularly well-suited to regenerative drive systems due to their heavy usage on hills and in mine shafts. While a diesel dumper truck may burn fuel while going down a mine, electric vehicles could actually gain energy on their way down. The Swiss Federal Laboratories for Materials Science and Technology (EMPA) said the converted Komatsu truck may be capable of gaining 40 kWh of its way downhill, something the standard mining truck does 20 times each day. This means 800 kWh of energy capacity could be gained through a regenerative drive.
Following its announcement, the Swiss collaboration said it plans to change over up to eight additional vehicles and the conversion package could soon be commercially available.