BATTERY AND ELECTRIC MACHINES
A holistic view on electrification
As a trusted partner to mining clients at every stage of the mining lifecycle , Stantec ’ s insight and design expertise is helping advance innovation within the industry . Of particular relevance to this discussion on battery and electric machines is the company ’ s net-zero mining practices .
IM put some questions to Jon Treen , Senior Technical Advisor – Sustainable Mining , and Paul Schmidt , Project Manager , Mining , Minerals & Metals , to find out how Stantec is preparing its mining clients for a transition towards electrified and net-zero operations .
IM : When it comes to the planning and implementation of new battery and electric machines , how holistically are mining clients thinking ? JS : The move to battery and electric machines has created a shift in the thinking of how to apply this technology at mine sites . People are thinking bigger picture when considering the implementation such as tramming down-ramp to generate energy , impact to overall power requirements , benefits to ventilation and refrigeration system costs . However , there is still room to grow to create a full holistic view . The solutions may not be replacing a combustion engine with a battery engine . It may be trolley assist , or other material movement methods where the conveyances are electrical .
Overall , the industry needs to look at how it can reduce its energy consumption ( green or otherwise ) and how does it convert the energy that does get consumed to a renewable green energy source . PS : The answer to these questions depends on the end user of a mining study . For the mining department , the implementation of BEVs or trolley haulage is based on health , efficiency and economics . The source of electric power is typically discussed at the project onset and government regulations drive the decision to switch from fossil fuels to solar or wind generation for the electric power source . Fuel and power costs are factored into our studies . In underground mining , combustion engines produce heat , diesel particulate matter and harmful by-products . The switch to electric vehicles can reduce chronic exposure to these by-products . Electric vehicles also have higher acceleration rates and more breakout force , which can increase efficiency .
The client corporate entity either needs government regulations and tax credits to make electric vehicles more cost effective than diesel equipment , or the company must take a stance to switch to these lower-end emission vehicles and absorb the higher capital and operating cost . The best opportunity for building an electric mine is during the planning phases of a new project . Retrofitting existing mines can be effective but requires significant capital investment .
IM : If you look at the expected energy draw of mines for the next five years and the rate of renewable uptake , is there an imbalance in terms of the amount of equipment / machines being electrified and the decarbonisation of the grid that will power them ? How are mines factoring this into their battery charging / swapping strategy in terms of staging the battery charge or , perhaps , using an alternative , low power method of topping batteries up ? JS : The energy draw from the use of an electrified fleet may create a reduction in power use at a mine site , specifically for underground operations . We are seeing the move to batteryelectric equipment resulting in a reduction in ventilation demand and refrigeration demand that offsets – partially or fully – the increase in battery charging demand . One challenge with the battery-electric equipment is that charging is not continuous . Charging occurs in short intervals and , by design , operators and OEMs are trying to reduce the charging times . However , the reduced charging time results in larger peak power demands . This issue may lead to a move towards more trolley assist or other continuous material conveyances that provide the same decarbonisation benefit without creating spikes in energy demand .
In the short term , where battery-electric equipment is the main solution to decarbonisation , I believe the industry will see an increase in short interval control . This will not just focus on maximising ore production , but also maximising battery efficiency . It will likely lead to decisions that will optimise battery charging times and schedule over optimising battery use . This could lead to scheduling times of battery changes prior to when a battery swap is actually required . The overall goal is to reduce the number of spare batteries required , reduce the infrastructure and level power demand for charging . PS : I cannot speak to the imbalance in energy . Will the mine use more electric power ? Maybe , depending on the required ventilation and cooling . What existing mines are not prepared for is the sudden use of power during a fastcharging cycle . One way to solve this is through the use of large capacitors at charging units and repurposed used batteries as power storage for these power bumps . The mines are following
There is an unrealised potential in re-use of low remaining capacity batteries to store wind and solar energy , according to Stantec ’ s Paul Schmidt
manufacturer specs in terms of charging time and power draw . Some manufacturers are opting for slow charging and battery swapping while other are using fast charging with onboard fixed batteries . The fast-charging options require more complex charging infrastructure to eliminate sudden draws when the power is switched on . There is an unrealised potential in re-use of low remaining capacity batteries to store wind and solar energy .
IM : What other considerations are you as an advisor and engineering firm often pointing out to clients considering increasing uptake of battery or electric machines ? JS : The main point we focus on with our clients is to consider more than just BEVs . It is critical to understand your orebody , its potential , the opportunities and the challenges , and determine what the best materials handling system is for the short term and potentially a different opportunity for the long term . Thinking in this way during the design stages is critical . The other item we focus on is being agile in the approach . The designs must not create such a rigid plan that changes cannot occur . The industry is still in the developing stages of these decarbonisation strategies . The solutions we have today could greatly improve in the next few years and operations need to be flexible enough to take advantage of advancements in the industry . PS : The focus is to consider all alternative solutions to fossil fuel use , not solely BEV or electric machines . We look at all methods to move material such as conveyors , Rail-Veyor , shafts , trolley and BEVs . For our clients , solutions that maintain optionality are key . The future is ever changing , and mine designs and haulage methods need to maintain optionality . BEVs for haulage are flexible and come with lower capital compared with a conveyor system . However , long mine lives may point to more fixed solutions .
42 International Mining | MAY 2023