EDL on Coober Pedy and Hybridisation

What do you see as the key drivers behind recent hybrid projects for miners and other industrial energy users?

In the past two years, there’s been increasing momentum towards the hybridisation of energy sources for mines and operations in remote, off-grid locations. The key reasons for this are the reducing cost of renewable technologies and the desire of companies to improve their social responsibility profile in a decarbonising economy as part of global climate change action.

Renewable energy enables miners to reduce exposure to price volatility of traditional fuel sources such as diesel or gas and increase cost savings, while at the same time curtail emissions and achieve sustainability targets. However, a switch to renewables can be costly and if not managed carefully can have serious impacts on reliability.

Hybrid technologies help bridge the gap between existing fuel sources and renewable energy, effectively managing the reliability risk and facilitating much higher penetration of renewable energy sources.

How do you see climate strategy and goals driving new energy choices for mines?

Australia is targeting a reduction in emissions to 26–28% on 2005 levels by 2030 as part of our commitment to the Paris Agreement. The mining sector is a significant contributor to Australia’s carbon emissions and miners have been taking steps to cut their emissions, even without a clear federal policy on climate change and energy.

We hope this will change after the recent Australian federal election. It is essential we get agreement on a policy that effectively and efficiently addresses all three limbs of the “energy trilemma”—that is, a secure and reliable, environmentally sustainable, least-cost supply. A stable policy framework will improve business confidence and enable the investment needed in new energy choices. An absence of clear policy benefits and aging, inefficient incumbent generators can result in increased costs to consumers.

Can you provide some examples of recent projects that push the envelope in terms of the amount of renewables penetration realized?

Our Coober Pedy Renewable Hybrid Project went operational in mid-2017, and has exceeded all expectations.

The targeted renewable energy contribution was 70%, however, the project has averaged 73% over the past 18 months. We had also estimated that 50% of the time, the remote mining town of Coober Pedy would be supplied with 100% renewable power (using zero diesel). This has been marginally exceeded at around 51%.

Now, around 73% of the diesel fuel supply to the site has been replaced by renewable energy sources.

What are the key takeaways for miners from the operational results from EDL’s Coober Pedy Renewable Hybrid Project?

The success of the Coober Pedy Renewable Hybrid Project demonstrates that renewables can provide high levels of stability and penetration without compromising power quality and reliability.

We focused our efforts on integrating all the generating technologies and maintaining a reliable supply of generation for the town’s dynamic demand. This paid off with an improvement in power quality and reliability, with fewer supply outages from generation issues compared to before hybridisation.

This project has provided invaluable learnings for EDL’s other two renewable hybrid projects—the Cannington project and a new power project at a mine in Western Australia consisting of 22MW gas and diesel generation, 4MW solar PV and 17MW of wind generation , and a 13MW battery.

What milestones have been met with this hybrid in terms of average renewable energy penetration and system reliability?

The Coober Pedy Renewable Hybrid Project has demonstrated that renewable generation can supply power with high reliability for extended periods of time.

In addition to the average 73% renewable energy contribution, in September 2017, shortly after the Coober Pedy Renewable Hybrid Project went online, it achieved a significant milestone through supplying 100% renewables to the town for an uninterrupted 35 hours.

The project achieved a site record in December 2018, with a 100% renewable energy supply for more than 81 continuous hours. There is strong potential for this record to be extended with the right combination of wind, sun, and load.

What are the next steps for this leading example of renewables integration?

EDL is working to fine-tune the controls of the Coober Pedy Renewable Hybrid Project to reduce costs and improve performance.

This could include smarter management of customer loads to match the available renewable energy and a larger battery to store excess renewable generation for later use.

We will leverage these learnings in future distributed renewable energy solutions for other remote, off-grid customers.

What do you see as the next steps in terms of renewables integration and decarbonization of mining’s energy supply?

Renewable energy solutions are increasingly forming part of mining’s energy management and their use will continue to grow.

As the cost of enabling technologies reduces, how they are adopted and used will change. More and more, batteries are part of the hybrid solutions, serving many purposes such as virtual spinning reserve; energy storage to enable the use of renewables for a longer period; and assisting with load steps.

These rapid advancements in technology create a dynamic environment. To maximise the benefits, we energy suppliers and our customers need to collaborate. We are starting to work with our mining development customers a lot earlier in the planning phase so that their mine processes suit the inherent differences of a high penetration renewable energy solution. For example, mining processes could be designed to follow the renewable load (more load during the day or when the wind is blowing).