Electric Vehicles For Mining: An Interview With Erik Svedlund

Interview conducted by G.P. ThomasJul 12 2013

Erik Svedlund, product manager for underground electric loaders and trucks at Atlas Copco URE, talks to AZoMining about the innovative new green line from Atlas Copco and the potential economic and environmental benefits.

Could you provide a brief overview of the new green line from Atlas Copco?

The green line consists of a range of electric loaders and electric trucks. The main commonality between them is that they all use electricity as main power source, and they give a hundred percent carbon dioxide free production. We are offering four electric loaders and two electric trucks as part of the new range.

The new green line from Atlas Copco. Image credit: Atlas Copco

So just to clarify, are the new vehicles within the green line fully electric or hybrids?

The loaders are hundred percent electric and they're powered by cable directly off the grid. The working area of mining loaders is usually quite confined, so it can run off a cable. That's one of the really unique things with our new electric loaders, because we have a totally new cable control system.

Cable powered loaders have been around for quite some time actually. The major issue with them has been the cable control, which up until now has been very rough. For example, the cable will have been quite stretched as it is pulled around corners and dragged across the rock, which of course damages the cable. That's been one of the major reasons why people haven’t been choosing electric loaders. That's one thing we have solved with our new range.

Another potential issue with electric loaders is that when you need to move them to another area and you unplug them it can be very difficult to move them. That's another thing we have solved now, to be able to enable electrification, or at least make it easier.

We have created a diesel generator, which is intended for use in transportation of the loader. You can tow this behind the loader just like a trailer on your car, up and down the ramp in and out of the mine, from different work area to the workshop. This has been a very difficult task before, but now you can do it with the operator alone. Before this moving was done by one or two diesel loaders towing the electric loader, which also required extra personnel. That's of course both expensive and difficult.

The trucks are use hybrids, when connected to the trolley line they run 100% electric but they also have a onboard diesel engine for movement and flexibility off the trolly line.

Electric Scooptram EST14. Image Credit: Atlas Copco

So, in your opinion, why is now the right time to introduce electric vehicles into the mining sector?

Well we have had electric loaders before, but not on this scale. The biggest one we had was the model EST8AES, but this was stopped a couple years ago because of lack of demand.

However, fuel prices are rising, so energy costs are becoming a big concern as is the environmental impact of mining. So customers are looking for more environmentally friendly solutions and we believe that this is the time to go electric.

It's not only for the environment actually; you can also make a lot of money by doing this. Already today you will save quite substantially on the energy costs. If you look at the energy costs, you will save about seventy percent compared to diesel equipment.

If you look at total cost of ownership, when you include everything, including operator, tires and so on, then electric verses diesel can give a total cost reduction of about ten percent.

That's only the looking at the production benefits – there are also other aspects to it. For example, an electric machine produces no diesel exhausts, therefore underground working conditions improve a lot.

Focusing on the economic benefits of the new green line, is there anything else you want to add about the potential savings?

As I mentioned, the total cost of ownership savings are somewhere around the area of ten percent for loaders but around 30% for trucks but that's only costs of the machines. There other saving aspects to it such as ventilation, so the benefits will normally be bigger.

Not all mines are suited for an electric loader and not all applications will work perfectly – there needs to be a little bit of planning or thinking of how you're going to make your production work with electric loader. Once that's done, the benefits are huge - there's a lot of money to be saved and health benefits to be had.

Energy requirements for the electric and diesel loaders. Image Credit: Atlas Copco

How does the use of electric loaders affect the use and need of underground ventilation?

With the electric loaders, there's no diesel exhaust at all. However, there's a little bit of heat, dust etc. so there always needs to be a basic amount of ventilation, but there's a huge reduction.

I had to learn a lot about ventilation when we looked into the electric machines, you need to understand the impact of the ventilation to fully understand the benefit of electric machines.

If you're going to move a certain amount of air, let's say one hundred units of air, which will give you energy consumption of X, and let’s say that’s one hundred percent. So if you reduce your ventilation need by ten percent, because we put an electric machine in your mine, then your energy consumption for that same fan and the same ventilation system and so on, will go down to thirty three percent.

The other thing is that even the small reduction in ventilation may mean huge benefits in ventilation. To increase your production, or even allow you to go deeper in the mine, you need more ventilation or longer shaft ventilation. The air pressure goes up and you have the same function, but the other way. For example, you go down to the next level, your energy consumption for the same volume of air might double.

If you can just change a few of your units in your mine to go electric, you might stay with the same ventilation cost as you did on the higher level. That might mean that your mine can still exist.

We're looking at South Africa for example, where they're looking to go real deep in the gold mine. They're going down below four thousand meters. It's going to be very, very difficult to ventilate these mines.

I was reading that the mine trucks, the EMT35 and 50, are potentially twice as fast as a traditional truck. What is the reason for this?

It's because the electric motors we have that generate a lot of power. The power-weight ratio is the main thing there. There is almost twice the power in the electric truck, and that's why it makes it so fast.

Going up, nothing will beat the electrical trucks today. No diesel trucks will beat it. However electric trucks are not always faster. For example, going downhill or on in a flat area, a diesel truck is just as fast or maybe even faster than an electrical truck.

Electric Minetruck EMT35. Image credit: Atlas Copco.

In terms of powering the vehicles and charging them, is this a difficulty sometimes in remote locations?

We’ve mainly talked about the loaders up to this point, so let's talk more about the trucks. Loaders are powered only by the grid, by a cable. The trucks are powered from the grid in its normal operation, but with the truck you can go off the grid. They have a small on-board diesel engine which is powering a generator, which gives them power so they can drive off the grid.

It's normal operation, but it's not intended to go on a ramp or longer distances. It's for going flat. For going to a loading place for example, to have the flexibility.

So the trucks are quite easy, they have their on-board power source when off grid. If they go on the grid, they connect to trolley line en-route and by doing that they get ten times more power than they do from the diesel engine. The diesel engine shuts off in standby until the operator disconnects from the line again. Then the diesel motor starts up automatically.

Where is the green line currently being implemented? Have you had any feedback about what people think about it?

The trucks are running in Canada and in the US where they are replacing more than ten year old trucks right now with new electric ones.

Our biggest fleet running, which is around thirty loaders today, is in China. The reason behind that is they think diesel costs are expensive and ventilation is expensive, and they're very cost conscious. In Canada, we have a fairly big fleet of electric trucks. Actually today, we've received a request for another truck for that customer in Canada.

I also just want to touch on the environmental benefits as well. I'm sure a lot of people will be aware of the environmental benefits of electric vehicles, but could you outline how you feel Atlas is contributing with the new green line?

There are many reasons for going electric. Environmental aspects are getting more and more focus and are now becoming just as important as safety and health.

However, it is a big issue for me personally and there are many environmental benefits to going electric. I mean, I can recycle all my cans and my glass, and drive a environmentally friendly car, but selling one of these trucks will have more environmental impact than all personal efforts combined over +300years !

I can help the environment so much more through my work and pushing this message out to the mining industry that says ‘Hey, you can do the environment a favor but also make money at the same time!’

Exactly. It's a win-win isn't it?

Indeed, we are quite proud to be the first OEM to offer something like this.

I strongly believe that we'll see a lot more electrical machines in the future. What we see now from Atlas is the first; maybe say the second generation of electrical machines. There will come about the third and fourth generation in the next maybe coming ten years. I actually believe in twenty years diesel engines may be banned underground!

Global CO₂ emissions. Image Credit: Atlas Copco

That leads nicely to my final question – How do you see electrical vehicles in mining progressing in the future? And what may be some of the roadblocks to this progression?

In terms of trucks, I believe they will become even more efficient in the future, but we are on the right lines today.

Looking at loaders, I think we'll see a big push toward battery operated loaders. The cable, even though we have solved most problems now, it's not ideal for everyone. I think there will be a cable and diesel hybrids over a transition period before we go totally battery powered.

About Erik Svedlund

Erik Svedlund has been working for Atlas Copco for the last 10 years. Erik started out in production, were he worked for one year, before moving to the technical service department.

Erik then worked as a service engineer for 5 years, which allowed him to travel the world and spend time with the customers and operators in the mines. This first-hand experience with the everyday work and problems of customers gave excellent experience and a "feel" for what is important.

Erik brought this experience with him when he moved to the marketing department, where he has been working as a product manager since 2008.