Chances are you’ve seen one of the multitude of wind farms that have appeared around WA over the past few years and thought to yourself “that looks impressive.”
You might well have seen an image of a worker high atop one of the giant turbines and muttered something like “better them than me.”
But what you perhaps haven’t done is taken a moment to think to yourself “how did they get it there?”
In the case of Gold Fields’ Agnew gold mine, where the five 110m-high wind turbines form part of Australia’s biggest renewable energy microgrid, the answer to that last question is “with a lot of planning and plenty of hard work and old-fashioned ingenuity.”
Nearly three years after it went “live”, Agnew’s microgrid – owned and operated by sustainable energy specialists EDL – is an international award winner and an illustration to the rest of the WA mining and resources sector about what can be achieved in the renewables space.
The story of how it physically came into being nearly 400km north of Kalgoorlie-Boulder is an epic that features both a journey across the high seas and the mother of all road trips.
That story begins in China, where the five sets of turbine blades and other turbine components were manufactured and then required their own ship to make the trip to Western Australia.
They landed in Geraldton, which is where the logistical challenges really started to kick in. As explained by Geoff Hobley, EDL’s General Manager Remote Energy, it’s more than 620km by road from the Mid West port to Agnew, each blade required its own road train and what might ordinarily be considered fairly standard road navigation was made much more complex by the cargo.
“There were actually 55 separate components that needed to be mobilised between Geraldton and the Agnew mine site,” Hobley reflected.
“That process took between 10 and 12 hours for each journey and it took eight days overall. The road trains for the turbine blades were 77 metres in length, which is a bit longer than your average road train.
“And it required special manoeuvring given they don’t bend in the middle. The process was managed by our contractor Goldwind, who liaised closely with all the relevant authorities and local communities.
“They had to realign roads and clear car parks. I had the opportunity to see them passing through the town of Mount Magnet, where they had to make a right-hand turn.
“But there wasn’t space on the main road at Mount Magnet for them to turn right. They actually had to build a new road around the outside of the town so they could do a big left-hand loop and then come back through the middle of town.”
As much of a logistical exercise as it was getting all the components to Agnew, construction of the wind farm was even more complex.
Each turbine is supported by a foundation consisting of 50 tonnes of steel and 500 tonnes of concrete, which had to be completed in one continuous pour delivered using 85 concrete agitator trucks.
The five separate sections that make up a turbine’s tower weigh each weigh between 50 and 100 tonnes, while the nacelle (complete with the generator) weighs 120 tonnes and the blades each weigh around 20 tonnes, while also sitting 110 metres above the ground.
All told the installation involved a crew of around 40 people working across 150,000 hours and specialist equipment had to be brought in for the job.
“The turbines were assembled with a 1600-tonne crane, and I think there were only two of them in WA at the time,” EDL Operations Manager Remote Energy Paul White recalled.
“It had to come down from the Pilbara and there was some fair logistical involvement in getting that crane down through to Agnew. Parts of roads had to be specially built so that it could crawl along.
“For the installation, the weather always is a conundrum when you’re putting wind turbines up. The one thing you don’t want when you’re assembling them is wind, which seems at odds with the outcome you’re trying to achieve.
“That’s why it took three or four days to assemble a turbine. The wind had to be below a certain speed and some of the lifts actually happened at night.”
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Global affairs were another complicating factor.
When the wind turbine components started arriving at Agnew in late 2019, the world was still a fairly normal place, specifically in in terms of movement of labour.
But as construction and commissioning was wrapping up in the first few months of 2020, the COVID-19 pandemic served up challenges that nobody could have foreseen when the project was initially devised.
“We actually ended up having two separate crews, one that was finalising construction, whilst the other was commencing commissioning on the already constructed turbines,” Hobley said.
“These two crews weren’t allowed to interact at all, they had to remain completely separate to manage any risk of possible infection.”
COVID-19 meant the Agnew microgrid wasn’t able to have an official opening ceremony until November 2021.
By that stage it had it had already been in operation for six months and was supplying the mine site with 50-60 per cent of its power needs from renewable energy on average, with a peak of up to 85 per cent in favourable weather.
Gold Fields Executive Vice President Australasia Stuart Mathews says the decision to invest heavily in renewable energy had paid off handsomely, in terms of environmental outcomes and other perhaps less tangible and unexpected ways.
In addition to Agnew becoming the first mine in Australia to be powered by wind-generated electricity, the microgrid features a 10,170-panel solar farm generating 4MW, a 13MW/4MWh battery system and an off-grid 21MW gas/diesel engine power plant.
All up the emission reductions benefits have been estimated at 40,000 tonnes per annum of avoided carbon dioxide equivalents, which would correlate to taking 12,700 cars off the road each year.
“What I really underestimated was what [the renewables project] did for the morale and motivation of our workforce at Agnew,” Mathews said.
“It’s the highest morale and motivation we have of any mine in our business. People, especially younger people, want to work for a company that believes in sustainability – not just talking about it but putting actions in place.
“Our employees are absolutely proud of it and it’s a point of difference for our business with both our current team and when recruiting new talent.
“We are now deep into planning and studies to find further applications across our other Australian mine sites as we focus on delivering our 2030 decarbonisation target.”
For the companies who have partnered with Gold Fields on the Agnew microgrid, there have been plenty of learnings to take away from the experience.
White said the fact Agnew was uncharted territory to a significant degree heightened the sense of achievement for EDL.
“We’d built Coober Pedy [renewable microgrid in South Australia] which is a great station but had lots of enabling technologies. This one had less enabling technologies and we relied more on advancement and control systems,” White said.
“The integration was one of the biggest challenges – once we got things going, for the guys to understand how it operated and how it worked and what the impact of each component had on the load.
“It was a new load, we didn’t know how load would react through step changes and how the turbines and all the integrated parts would work together.
“The control system was a big part of it and then our people had to do a fair bit of work to make sure that it all worked together.
“It was an interesting exercise for them to learn how all the components fitted together, what the interaction was for each of them and how that impacted the whole system.
“The hybrid microgrid is quite an interesting beast in that all the components impact it in some way. And you have to understand that.”
Hobley said Agnew and its ongoing recognition represented a source of both learning and pride for EDL.
“As with many hybrid projects, it’s operationally far more challenging than a straight fossil fuel power station,” Hobley said.
“They are more challenging in the construction, they are also more challenging in the operation. We continue to learn from this project and we take that learning forward to all the new projects that we’re developing and constructing.
“So the recognition that the project gets, both within Australia and internationally, I think brings a really good feeling to everyone in our business.
“People work here because they enjoy working on these sort of projects and they enjoy working for EDL.
“It adds to the whole culture of the business and the way people interact. It’s really, really beneficial.”
Wind farm images in the main photo of this story were captured by Christian Sprogoe.