Where will that electricity come from?
How will the mine of the future be run? Many indications are that it will be electric. So where is that electricity going to come from?
Miners are increasingly turning to renewable energy as a means to decarbonise their operations.
However, that is not the only way forward for miners looking to decarbonise. After all, there are issues with renewables. The bulk of the renewable efforts at Australian mines revolve around solar and, more recently, wind, generation. As critics of renewables are quick to point out, they are no good when the sun does not shine and the wind does not blow.
Gas-fired power stations offer a means to reduce carbon emissions while meeting the operation's power demands 24-7. Put renewables into the mix and the decarbonisation benefits increase.
However, the cost of setting up the pipeline infrastructure, even it is possible, can be prohibitive, particularly for operations with relatively short mine lives.
When it comes to introducing renewables, the life of the mine and the capital cost of the renewable solution need to be considered. Solar is stealing a march here because the technology has advanced to the point where systems can be put in with minimal infrastructure and then packed up and moved to another mine site as needed. Wind farms, not so much.
Does nuclear have a place in the mining world? Small modular nuclear reactors offer a solution for miners going forward. One European miner is already heading down that route. There could, however, be problems for Australian miners taking a similar tack - the lack of a domestic nuclear industry not being the least of them.
Then it comes to using that power. The electrified mine of the future will no doubt look a bit different to the diesel-fired one of today. That will pose a challenge for mine planners.
The equipment being deployed in these electrified mines will bring challenges - haul trucks cannot make it up a decline on a single charge at the moment - as well as opportunities, some obvious and some less so.
It's a gas
Aggreko global head of mining Rod Saffy told Australia's Mining Monthly when if a miner wanted to consider gas and tapping into a pipeline was too expensive, there was another option: create a virtual pipeline.
This involves trucking gas to the mine to keep the turbines turning and burning.
Saffy pointed to BOC trucking gas about 900km to the Hera mine in New South Wales and Ora Banda Mining's recent virtual pipeline to its Davyhurst operation 600km northeast of Perth, Western Australia.
"The customers have been able to reduce their diesel emissions by switching from diesel to gas," he said.
"It takes the right type of engines to do that."
Over the past two decades a number of miners in WA's far eastern Goldfields region have opted for spur lines from the Goldfields Gas Transmission line that runs from the state's northwest to Kalgoorlie.
Saffy said getting capacity in that line these days would be challenging and warned the mine needed to have a fairly long life to pay for a spur line.
"With the Granny Smith mine there's 10-15 years' mine life so it's easier to justify the cost," he said.
"Davyhurst is a five-year term."
Stick it where the sun shines
Saffy believes renewables are going to play a bigger role in mine power going forward.
He said if everyone had a pick of available fuels they would go for the highest level of renewables they could.
"One of the biggest challenges for mining companies is they have their existing project," Saffy said.
"There is a lot of sunk capital there. They have generators on the ground that need paying off.
"They don't just have the luxury of starting anew.
"There are a number of mines with short terms. There are a number of mine with long terms. There are old mines wondering what they can do.
"In the first instance people are asking if we can help. We have to take each case on its merits.
"I haven't seen a single requirement for any longer-term mining operation that doesn't have some renewables. How long is the contract? How close are you to a pipeline? If you have a longer-term view you can look at project projects like wind. It's 10-years for wind to be viable.
"We're also looking at short-term renewable options. We're working with a company like 5B that has mobile and modular solar products.
"That's proven to be a good product on a short-term and a long-term basis."
Mine life played a part in IGO's decision to expand the solar farm at its Nova copper-nickel-cobalt operation 360km southeast of Kalgoorlie, WA.
It already had a solar plant there and, given the mine only has about five years left, the thought of putting down more infrastructure was not highly palatable.
The existing solar plant was installed by Zenith Energy and sits on concrete footings with a mechanism that allows the panels to follow the sun.
Zenith Energy came back to IGO with a solar panel alternative that only required mounds of dirt to be erected. The panels are on A-frames the mounds of dirt are used to anchor them.
IGO COO Matt Dusci said the entire second solar farm would be connected within four to five days.
When Nova closes those solar panels can be packed up and moved to the next site and the clean-up is relatively simple: a bulldozer can be run through to flatten out the mounds of dirt and the site can then be revegetated.
Dusci said the ability to reuse that second solar farm got the project over the line.
The additional solar plant, along with a 10 megawatt hour battery energy storage system and the existing solar plant, will allow IGO to operate for up to nine hours a day "engine free".
Saffy said people looked at what they could do with what they had.
"If it's a diesel station, can we bring in something to reduce carbon?" he asked.
"People building new power stations are asking what they can do?
"It's a known fact that the biggest costs for mining companies is the cost for labour and the cost for power."
Indeed, when it comes to designing a processing plant the first consideration is how much power can the operation afford? A ball mill or a semi-autogenous grinding mill can account for 5-10MW.
Saffy said there were ways to reduce the draw of the mills.
"With ball mills when they get hot their hydraulics struggle," he said.
"We've put a blast cooling system on them which can help cool their hydraulic system and improve efficiency."
The other gas
While LNG has been the go-to for miners, another gas is starting to expand in their thinking.
Engie Impact senior director Josh Martin said hydrogen was an emerging renewable energy technology.
"We did some work with OZ Minerals at West Musgrave looking at having hydrogen and renewables," he said.
OZ Minerals wants to West Musgrave to be a zero carbon mine.
Martin said Engie Impact was also working with Anglo American on a large hydrogen truck.
While there is a lot of investment in hydrogen research, there are few if any commercial solutions available.
"It comes a bit more challenging," Martin said.
"By 2030 we'll have more certainty with these sort of technologies.
"The best thing a mine can do is map out what they are going to do.
"They should look at technologies that make sense financially and have a low risk but also be aware of what technologies are emerging and could have an impact on their operations."
As Dusci points out with IGO's decision to add the second solar farm and a BESS, the pace of technological change can make a big difference.
It was the change to the solar farm approach that made it financially viable.
A new plan
An all-electric mine will change a number of traditional mine design principles.
However, while there are likely to be some big wins - ventilation being one of them with a 35% emissions reduction predicted - knowing how big these wins will be challenging.
When somebody fully electrifies a mine there will be reams of data available to those willing to follow. Until then there is no way to holistically demonstrate or validate the assumptions associated with the design principles of an all-electric mine.
The Electric Mine Consortium's mine design working group, led by OZ Minerals, is running a global crowd challenge to attract companies and individuals from around the world to propose approaches for developing a scaleable electric mine design simulation platform.
Gold Fields has also partnered with Dassault Systemes to apply simulation techniques to greenfield designs under construction.
Several mine planning software makers have allowed for the introduction of electric vehicles in some of their simulations.
Besides OZ Minerals and Gold Fields, other members of the consortium are South32, IGO, Barminco, Evolution Mining, Blakstone Minerals and Newcrest Mining. Besides Dassault the EMC's partners are 3ME, Slate, Nukon, Energy Vault, Epiroc, METS Ignited, Sandvik, Zenith Energy, Zero Automotive, Amazon, Vivo Power and Deswik.
There are challenges with electric equipment. According to the Electric Mine Consortium, bottlenecks in global supply chains for battery technology and semiconductors are expected to create a shortage of more than 26 million vehicles between 2021 and 2029.
The EMC's A case study in transformative collaboration report finds Australia will require up to 21 gigawatts of dispatchable resources to support the transition to renewable.
"The remote mining operations in the EMC and our large-scale pilots have a unique opportunity to show leadership in demonstrating the role that long-duration battery storage - other than lithium - can play in the power grid, beyond just stabilisation," the report says.
Dusci said IGO had considered turning Nova to an electric-haulage operation, however, the costs would not stack up.
Nova has a 400m decline, which is not large by Australian standards, but still too long for an electric haul truck to manage on a single charge.
If Nova was being designed today with electric equipment in mind a number of changes would be made.
Ventilation requirements would be much less, which would require smaller drives and smaller vent bags.
It would also allow the introduction of a trolley assist system into the decline to help the haul trucks get to surface and also recharge while they are doing it. On the way down regenerative braking would help top up the batteries too.
However, given Nova already has the ventilation equipment installed for diesel operations and the drive sizes have been cut with diesel in mind, a switch to electric vehicle haulage is not being considered.
"We're looking at it from a carbon emissions perspective and our largest carbon emissions are from power generation," Dusci said.
He said while electric trucks were off the table, electric drills and jumbos would certainly be considered.
The drills and jumbos would only use their batteries to tram to where they were needed. Once they reach the drill point or development face they connect to the mine's services to power their drilling activities. That link to mine power can also be used to charge the batteries.
Dusci said the IGO was working with mining contractor Barminco on its electric fleet needs for Nova.
Under the deal Barminco provides the equipment and IGO provides the charge. The miner has committed to about $1 million in charging infrastructure over the next two financial years.
For light vehicle a fast charging and slower charging options are being considered depending on the vehicle's use pattern.
Dusci said for supervisors and foremen, who typically spend more time at the surface, a slower charging option could be used while fitters, who need to move around more, would likely need a faster charging option.
Saffy said an electric mine concept could also change the thinking around light vehicles.
"A medium-sized mine has about 50 utility vehicles," he said.
"If every one of those vehicles needs to be plugged in, those vehicles become a battery bank. You are looking at a 2MW battery source.
"Can those vehicles be used for load balancing? There are a lot of things up for grabs.
"Are you using the power well? There are companies that can come out and audit the power usage. Various stages of the mine can often run independently of each other. Is there a way to do this better?"
Time to go nuclear?
Small modular reactors have been hovering on the fringes of mine electrification for some time, however, nobody seemed quite ready to take on the technology.
They have proved to be viable. After all, the SMRs being proposed for mine sites are not too dissimilar to what has been used in various submarine fleets for decades.
Polish copper miner KGHM recently signed a contract with US-based SMR provider NuScale for SMRs to be implemented in Poland, possibly as early as 2029.
For KGHM SMRs will help it meet its goals of carbon reduction and energy independence.
KGHM Polska Miedź management board president Marcin Chludziński said he was proud KGHM was leading the initiation of a 100% carbon free energy project.
"The SMR technology will increase the company's cost efficiency and transform the Polish energy sector," he said.
One potential SMR application is to have it arrive at the mine site on the back of a truck and simply be plugged into the mine's systems.
Martin said while SMRs offered zero-carbon power generation there were things miners needed to consider if they wanted to deploy them.
"I know Engie does a lot of work in the space," he said.
"The challenge in Australia is we don't have a nuclear industry established."
Then there is the issue of disposing of spent nuclear fuel.
This article first appeared in sister publication Australia's Mining Monthly on February 18. Credit: Noel Dyson