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Interview: James Koerting, Energy Manager, Gold Fields Australia - Austmine

Friday, 23 October 2020

Energy remains a critical topic for the mining industry as it seeks to transition to a sustainable future.

Mining companies the world over are investigating the benefits of renewable energy for their operations, but Gold Fields have truly been a leader in implementing and fast-tracking the technology.

This sustainability leadership has been highlighted by the installation of one of the world’s largest hybrid micro-grids at their Agnew operations, along with the hybrid energy project at their Granny Smith mine.   

Ahead of his presentation at Austmine’s upcoming Smart Mining Networking Event, we caught up with James Koerting, Energy Manager, Gold Fields Australia to discuss what is driving their adoption of renewables and how this has benefited their operations.  

Gold Fields has a vision of becoming the global leader in sustainable gold mining, and the Agnew Hybrid Renewable project means you are on track to be the first Australian mine powered by a wind, solar, battery and gas microgrid. With the project now complete and in operations, what impacts do you see coming from this significant innovation?

Corporately, Gold Fields are sending strong signals to the company’s stakeholders that we are committed to our vision and values and are motivated to reduce our impact on climate change.

“On the technical side, we have taken the time to understand the risks with investing in a multi technology, complex and variable electricity supply system with a belief that what we have invested in at Agnew will become the future for off grid mines.”

The project runs on 54% renewable power over the course of a year. Our solar and wind resources are stronger in summer, but every day will be different in terms of the supply mix. These sources really complement each other, most of the wind energy is generated at night and solar during the day.

We had the funding to de-risk this and being able to do this helps bring the cost of investment back down. The knowledge we have gained will benefit not just Gold Fields global portfolio of operations but assist the wider mining sector to decarbonise and electrify with renewable energy. 

What has been your experience of investing in renewables options?

On the surface the technologies could be viewed as relatively simplistic everyday items that we have on our roof or have seen driving out in the country. People are comfortable with that technology but when you bring that to a mining context you start seeing the complexity of having variable energy supplies together.

When you combine these technologies on a microgrid your start to understand the complexities of their modes of operation and how this could impact the security of supply of electricity to the mine. To get past these challenges the lithium battery is the prevailing technology to firm up the supply security but comes as an additional cost to the project. As you push the renewable component up the battery requirement increases, and to push renewables higher than what we have at Agnew we will need to start thinking about other technologies such as synchronous condensers.

The other experience is around data needed to develop a renewable project both from a demand side and from a renewable resource side. We used a device called a SODAR to collect the wind resource, a minimum of a years’ worth of wind data is expected before the ideal wind turbine platform can be selected.

“If you are thinking of using renewable energy at your projects, my advice is to start as early as you can so that you’re ahead of your timeline for your project. Each site is different and there needs to be research and modelling to determine which renewables are best suited for which site.”

What qualities are Gold Fields Australia looking for when partnering with METS companies on renewable technology? What skills do they need to develop?

Energy security is critical for our projects. Once this is turned on, you need to be 100% sure this is robust. For this reason, mining companies have always taken a conservative approach.

With renewables we are looking for some proof of concept, operating experience and most importantly, integration experience. Then we are looking for new technologies that can improve the fraction of renewable energy we are getting from our solar and wind generators.

“These technologies of interest include instruments and software that can predict or forecast the renewable resource in real time and innovative ways to store excess renewable energy for future use.”

For processing operations there is interest in plant technology that can operate at variable rates in line with the variable nature of renewable resources.

What role do you see for renewables in addressing future energy challenges?

In Australia, renewables are coming to the forefront in assisting mining companies reduce their carbon emissions, but they are currently only effective on the electricity side.

We use energy for electricity and mobile equipment. The electricity side is easier to solve when decarbonising the mine. We are already at 54% at Agnew, with opportunities to grow the renewable share (aim to go over 70%). But mobile equipment is still mostly powered by diesel.

“Mining’s demand for fossil fuels in mobile equipment is a while away yet from being replaced with electrification, but when it is renewables will be well established to power the mining fleet of the future and assist with producing greener commodities in a low carbon world.”

We know that in international markets they are using electric mobile equipment and we are starting to investigate powering ours with renewables as well.

Gold Fields globally is also excited to grow our supply portfolio with more renewables having a number of new projects in the pipeline.

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