Off-grid gold miner says 100 pct renewables is possible after running 84 hours with “engine off”

The owner of one of Australia’s biggest and most valuable gold mines says it has run its off-grid facility for 84 consecutive hours with the “engine off”, proving that 100 per cent renewables is possible for remote industries.

Bellevue Gold has installed one of the world’s biggest off-grid arrays, with 24 megawatts (MW) of wind, 27 megawatts of solar and a 15 MW, 30 MWh battery, supported by 9 MW of diesel capacity and 15 MW of gas capacity.

The wind turbines only started production in May, but in the last two months have delivered an average renewable share of 78 and 88 per cent, better than initial forecasts.

“The renewable energy power station has powered the mine on 100% instantaneous renewable energy via ‘engine off’ mode during times of adequate solar and wind resources,” the company says in its latest sustainability report, touting its claim to be the first “net zero” mine.

“This included a period of 84 consecutive hours in August 2025, where the mine was run on 100% renewable energy, proving that operating on 100% renewable energy is possible, and part of a growing trend among other off-grid miners with renewable energy.”

The gold mine was officially opened last year and has progressively ramped up its renewables share, with the last of the solar PV capacity installed in July, and the first of the four 6 MW turbines installed in late April.

Those four turbines are now fully installed and the additions have allowed the mine to progress from just 14 per cent share renewables in July last year to 64 per cent renewables in June, before leaping to 78 per cent in July and in August it leaped to 88 per cent.

“Bellevue Gold is forecast to be the most renewably powered off-grid mine in Australia, with more than 80% renewable energy penetration on an annualised basis forecast for fiscal year 2026,” the company says in its report.

The company’s next move is to look at electrification in other areas of its activities, including electric vehicles and equipment above ground and in the mine, long duration storage, timing more activities to coincide with abundant wind and solar, and looking at other opportunities to use spilled energy.

“One of our major emissions reduction measures is the use of a state-of-the- art mine ventilation system to reduce the ventilation’s power consumptionby up to 30%,” it says in its report.

“This is achieved through the optimisation of fan speeds to significantly reduce vent circuit energy requirements. The Ventilation on Demand (VoD) system is equipped with variable speed drives (VSD) for the secondary fans.

“Now that the renewable energy power station is fully operational, we will investigate ways to better harness this renewable energy to reduce costs and emissions.”

It notes that the 27 MW solar farm is among the largest of its kind globally at an off-grid gold mining operation and is the eighth largest solar farm in the state, including on-grid and off-grid solar farms.

The power plant – combining the wind, solar, battery storage, gas, and diesel, as well as a synchronous condenser and microgrid controller – is operated by Zenith Energy, with a long term PPA (power purchase agreement) between the two companies.

See also: Gina Rinehart-backed lithium mine achieves 81 pct renewables over last year, with wind, solar and battery

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