Mining giant eyes wind, solar to power huge nickel project

Australian mining giant Oz Minerals says it is looking at use wind and solar to provide the bulk of the power needs for a giant new nickel project in a remote part of central Australia near the border of South Australia and West Australia, some 800kms west of Uluru.

Oz Minerals says a 55MW hybrid power plant would look to harness solar and wind energy to provide 70 to 80 per cent of the power needs of the West Musgrave project, backed up and balanced by battery storage and diesel generators.

Oz Minerals says lower cost wind and solar are a crucial part of the decision on whether to go ahead with West Musgrave, which is Australia’s largest undeveloped copper and nickel project, given that power costs account for around 40 per cent of the processing costs.

“Large-scale solar photovoltaic and wind solutions are currently economically viable and technically mature solutions to reduce the project’s reliance on high cost fossil fuels for electricity generation,” the company says in a presentation released on Tuesday along with its half year results.

“Baseline data collected over the last year has demonstrated a high quality, consistent solar and wind resource is available, with higher wind velocities at night offsetting the lack of solar power.”

Oz Minerals is just the latest of a number of big and small mining groups that are now turning to wind and solar to deflect the soaring costs of diesel or gas generators, the traditional source of supply of mining projects. But this would be by far the biggest.

The cost of wind and solar costs have plunged significantly in recent years and are clearly the cheapest source of bulk power by some margin. Now, the development of battery storage and integration technologies has given miners the confidence that this is a reliable source of power too, perhaps more so than diesel and gas generators that require significant amounts of back-up.

And the savings could be huge. Mines is such remote locations could be expected to pay up to $400/MWh for electricity from diesel, and would have to budget for than $2 billion of fuel costs over the life of the mine. Having wind and solar provide 80% of that supply will deliver significant savings.

Warner Priest, from Siemens, says a mine that can source around 70% of its needs from wind and solar, will ultimately be able to use hydrogen technology, such as electrolyses, and move to 100% renewables – for power and electric transport – and move completely away from diesel, natural gas, LNG or CNG.

The experience of Alinta with a big battery at the Newman gas generator in the Pilbara, which is supplying huge iron ore mine owned by Gina Rinehart, has dramatically lifted reliability and reduced the need for gas turbines to be switched on as spinning reserve. Now, a 60MW solar plant is also being considered to further reduce costs.

Wind-solar hybrids have proven their success at other off-grid sites, and several new projects will further develop the integration of wind, solar and batteries at mines such as Agnew in West Australia.

Oz Minerals itself announced in June it will trial a small wind, solar and battery hybrid facility at its Carrapeteena copper-gold mine, located to the north of Port Augusta. That facility is looking to combine only 250kW of solar PV capacity, a 10kW wind generator and a 250kW lithium-ion battery storage system, and to use the facility for electric vehicle charging.

At the recent Energy and Mines conference in Perth, it was suggested that wind and solar would likely provide at least 50 per cent of power needs in mines in the near future because of their lower costs.

Some mines are looking at even greater share, up to 90 per cent in the case of Element25 and their planned manganese mine and metals processing plant at Butcherbird in the Pilbara. Some have suggested they could go to 100 per cent renewables.

The West Musgrave feasibility study, led by Oz Minerals along with its junior partner, Cassini Resources, has looked at a range of different innovative technologies and processing which will reduced the capacity needs from 65MW to 55MW.

West Musgrave combines the Nebo and Babel copper and nickel deposits, could be a huge 10 million tonnes per year operation.  in Western Australia; some 800 km west of Uluru, near the intersection of the borders between Western Australia, South Australia and the Northern Territory.

The innovative approach include the use of a reduced site footprint via a Remote Operations Centre, the use of hybrid power solutions, potential to use innovative technology and a process flowsheet which pilot testing has shown could result in a significant reduction in power usage.

“We believe these opportunities have the potential to reduce our carbon footprint and power costs versus a traditional mine footprint while improving overall project economics,” it says. “A 55MW hybrid diesel-solar-wind solution with 70–80% renewable penetration is the current base case.”

Oz Minerals says a large number of proposals have been received from major utilities, independent power providers, infrastructure funders and equipment manufacturers.

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