Gruyere gold mine adds solar and battery with new hybrid microgrid

Another Australian mine is making the shift to renewable energy, albeit in increments, with the addition of solar and battery storage to an existing and expanding gas power facility at the Gruyere Gold Mine in Western Australia.

ASX-listed energy infrastructure outfit APA Group said on Tuesday that it entered into a two-phased power expansion agreement with the gold mine – a joint venture between Gold Fields and Gold Road Resources – to increase its total installed capacity from 45MW to 64MW.

The $38 million project will, in the first phase, install a twelfth reciprocating gas-fired engine at the mine in the north-eastern Goldfields region of Western Australia, and in the second phase install a utility-scale solar array and battery storage.

For stage two, APA will build, own and operate a 13MW solar farm backed-up by a 4.4MW/4.4MWh battery energy storage system, as well as a hybrid control system combining cloud and weather forecasting, battery management and the existing reciprocating engine control systems to optimise efficiency and maximise the use of renewable generation.

APA says it expects to have the new hybrid expansion commissioned in Q4 2021, at which time it will cut the carbon intensity of power supply to gold mine by roughly 10 per cent.

For APA, the Gruyere microgrid marks the first hybrid energy investment for a company that calls itself Australia’s largest natural gas infrastructure business – it’s behind the soon to be built Northern Gas Interconnect (NGI) that will add 2,690km of pipelines running north to south and west to east across W.A.

“This new Gruyere battery storage and microgrid project is an exciting first for APA, demonstrating our ability to respond to the needs of our customers with world-class energy solutions,” said APA Group managing director and CEO Rob Wheals.

“This project builds on our existing energy infrastructure footprint in the remote mining region of the northern Goldfields and will enable Gruyere JV to continue to unlock the potential of the Gruyere Gold Mine, while maintaining energy supply reliability through a sustainable power solution for the mine site operations.

“Consistent with our purpose to strengthen communities through responsible energy, we are delighted to be working with the Gruyere JV on this innovative energy solution,” Wheals said.

APA says it will continue to supply Gruyere with gas for the microgrid on a take-or-pay basis via its interconnected gas pipeline network.

The “take-or-pay” part of the deal may also explain why the mine’s owners haven’t been aimed higher on renewables for the mine’s power expansion, for now, having already contracted to pay for a set amount of gas supply. (One Step Off The Grid reached out to APA to clarify if this was the case, but had not heard back in time for publication.*)

For the South Africa-based Gold Fields, which is the mine operator and manager of the Gruyere joint venture, the shift to renewables in Australia and abroad is a major part of the company’s long-term business plans.

As RenewEconomy has reported, Gold Fields has been active in powering its mining operations with renewables in Australia, having converted its Agnew mine near Leinster in W.A. to more than 50% renewables via a hybrid wind, solar and battery storage system.

It has also installed 8MW of solar and a 1MW/2MWh lithium-ion battery at its Granny Smith mine, which has been integrated with the mine’s existing 24.2MW natural gas generation.

In a panel discussion at this year’s online Energy & Mines summit in August, Gold Fields Australian vice president, Stuart Mathews, said the miner was “very comfortable” with investing in more renewables as more of its power supply contracts came up for renewal.

“Our longer-term view is that we’re very comfortable, especially after our Agnew experience, and also the experience we’ve had at the Granny Smith mine as well … that it’s the perfect time to take that leap of faith,” he said.

“Going forward, in other parts of our business in Western Australia, Gold Fields is definitely in the study phase and looking to bolt on additional energy through renewables.”

*APA responded to One Step’s email after publication, but could not comment on why the mine power expansion project had not included a larger portion of renewables/battery storage. A company spokesman did clarify, however, that APA “has been investing in renewable energy over the last 11 years and we [are] now Australia’s 6th largest owner of renewable power generation assets, with just over half of our power generation coming from wind and solar.”