Developing renewables for remote mines is economically feasible for Gold Fields, with the Agnew mine renewables energy solution delivering around 56% of the mine's power requirements, with significant upside potential. Partner Sebastian Rosholt spoke with Stuart Mathews, EVP at Gold Fields Australia at IMARC 2023 about their renewables and decarbonisation initiatives.
What is Gold Fields' approach to decarbonisation?
As one of the early leaders in this field, Gold Fields started the journey as far back as 2012 when we started talking about sustainability, and especially, energy solutions for our mines. Since 2016, when we officially launched our energy and climate change strategy, we've been on a journey to implement these initiatives and meet our commitments to the Paris Agreement. We have a belief in our company in climate change and the need to decarbonise our business and find innovative solutions to mining for the future sustainability of our business. What we have done is we've managed to show belief in that by actually getting some big projects off the ground and delivering early that an investment in renewables can work and make business sense. It’s been a great motivator for our people and for attracting people to our company, because people want to work for a company that's looking to do innovative things and is actually trying to play its role in helping the planet.
What role does renewable energy play in powering Gold Fields' mining operations?
At Agnew, we have a renewable energy solution in place, which includes wind and solar, delivering around 56% of the mine's power requirements by renewables. We have five wind turbines with 18-megawatts of generation, and we have a large solar array as well. On average, that gives us 56% renewable power. On a good day, it can be up to 70% or even 80%, when wind and solar conditions are optimal. The current average is around 56%, but we have an expansion plan approved that will start in the new year, which will lift the average to between 66% and 70% renewable power in the mine’s electricity mix. That's important for Agnew, which is mining deeper and requiring more power. So additional power that we add on from this point onwards will be renewable.
At St Ives, our biggest mine in Australia, we're completing a feasibility study right now on a renewable energy solution which would provide 80% renewable power. That project will probably have seven to 10 wind turbines, generating around 42 to 45 megawatts of power and another 35 megawatts of power generated by solar. That's going to be probably one of the biggest micro-grids in this country. We're close to approving that project within the next three to four months.
At Granny Smith, we have around 13% of our power generated by renewables, and we're about to add to our solar capacity there. We've also committed to a study on wind energy.
At Gruyere, which is a joint venture with Gold Road, we already have a solar installation in place and plans for further expansion. Around 10% of Gruyere's power is currently generated by renewables from a large solar array. There is already a feasibility study in progress for an expansion with solar and wind solutions, aiming for 50 to 60% renewable energy.
Offshore, in South Africa at our South Deep mine, we have 50 megawatts of renewable power being generated by solar, with plans to expand that with additional solar and wind capacity. We are also looking at renewable solutions in Ghana, although that's a little bit more challenging from a renewables perspective as they don't have the wind or the solar intensity due to the humid atmosphere. In South America, our Cerro Corona mine in Peru is exclusively powered by hydro, while at Salares Norte, our mine in Chile that is coming on stream shortly, we will be adding solar capacity in about a year’s time.
Do remote renewable energy projects provide an economically viable energy source for mines?
They do. I think it makes absolute sense for us, especially in Australia where all our mines are in remote locations. It makes sense to look at innovative energy solutions like renewables because you can build and generate power on-site. You don't have to bring in power lines from all over the countryside at great expense. So, it makes economic and business sense to choose innovative energy solutions. Additionally, we can capitalise these projects ourselves to get the benefit straight away on the operating cost line because it's the cheapest power that we can generate. We're looking to fully fund the St Ives micro-grid because doing that will give us an immediate cost benefit on the mine's operating costs. We could drop our costs by something like A$38m per annum just through a renewable energy solution alone, which is significant and opens up all sorts of opportunities for our mines in the future. It’s definitely a solid business case.
Is wind a practical energy solution for mines?
Wind technology has been real game changer, as it moves the dial on the efficiency of renewable energy. What we found, especially in areas that we operate in, namely the interior Goldfields region in Western Australia, is that it's actually quite breezy out there. Agnew is a case in point. There was nothing wrong with the previous, long-term supply agreement we had in place or the company providing the power. This just came at a time that we felt it was time to go it alone and try something innovative, because we would probably have had to invest in major infrastructure upgrades like power lines had we not done. So we came up with a renewable solution. We worked with a partner, EDL, an independent power producer, who brought other service providers on board. They were great partners to work with, and they essentially brought the technology and built the project for us. That was a fairly seamless exercise, and it gave us the confidence to go forward with a lot more renewables projects and, increasingly, fund them ourselves.
How is decarbonisation of Gold Fields' existing truck fleet progressing?
We're more advanced technology-wise with mining fleets in open pits than underground, especially at the scale that Gold Fields is mining underground. The technology is already there for shaft environments because they're running on flat tracks. We need 50-60 tonne truck capacity to haul up declines with one-to-seven gradients. We're looking for that step change in technology to have electrified fleets in our mines that won't run out of power within an hour because they're running up steep ramps.
The OEMs are working on this, and each year we're getting better truck and loader options for underground mining. OEMs are already committed to working on the bigger truck options to satisfy mines that have steep declines and not just run shafts. The technology is moving in the right direction, but it's still a while away. We want to give comfort to OEMs that we want to be the first to get that technology in our mines when it's available and economically viable. It's important that they progress, but at the same time, we are looking at alternative solutions at a larger scale because our energy costs are being significantly reduced in the current decarbonisation and renewable energy transition.
Please contact our team for tailored advice on renewables energy solutions in Australia.
