Fortescue halves turbine numbers for huge Pilbara wind farm, still shoots for 2 GW capacity

Andrew Forrest’s 2 gigawatt wind plans to help decarbonise his Pilbara iron ore operations have undergone a “substantial redesign,” new documents reveal, including a halving of the number of turbines proposed for the project.

Pilbara Energy, a subsidiary of Forrest’s iron ore behemoth Fortescue, is proposing to develop the Bonney Downs wind farm around 9 km south-west of the town of Nullagine in Western Australia’s Pilbara region, near the company’s Christmas Creek iron ore mine site.

The original plans, as Renew Economy reported in October of last year, proposed the installation of up to 200 wind turbines and six substations, with a target installed renewable energy capacity of around 2.1 gigawatts (GW).

The “disturbance area” of the project was proposed to include the Bonney Downs, Hillside and Roy Hill pastoral leases – the latter held by avowed renewables opponent and fellow iron ore magnate, Gina Rinehart.

The proposed project had also sparked a legal tussle with Alinta Energy and the new owner of its Pilbara assets, APA Group, over its own renewable energy plans for the region, which appeared to overlap with Bonney Downs.

In updated referral documents published by the Western Australia Environment Protection Authority late last week, Pilbara Energy says a substantial redesign of the project has resulted in a major reduction in scale that has more than halved its total development footprint, while still aiming for 2.1 GW of generation capacity.

It’s unclear how this capacity would be achieved, however, with current individual onshore wind turbine sizes topping out at about 15 MW.

“Following an iterative design and assessment process… the proposal has been substantially reduced to avoid impacts wherever possible,” the documents say.

“This has included significantly reducing the number of turbines from 200 to 100 and implementation of large areas of exclusion zones around important areas of vegetation and habitat throughout the [development envelope].

“As such, the IDF [Indicative Development Footprint] for the Proposal is less than half that of the originally proposed design,” it adds – reduced from around 2,044 hectares (ha) to around 944.07 ha.

The new referral documents also note design changes to ensure turbines are not located on hills or mesas and to mitigate “noise exceedances” at the Bonney Downs Homestead, including through potential modifications to the turbine layout design and operational adjustments to wind farm turbines.

“The Proposal has been substantially reduced to avoid impacts wherever possible,” the documents say.

“As such, the IDF for the [updated] proposal is less than half that of the originally proposed design which substantially reduces the proposed vegetation clearing.”

The referral documents say that Fortescue opted for wind generation to power its operations in the region because it allows for 24-hour generation and has a smaller footprint than solar and battery storage, therefore resulting in a smaller environmental impact.

“It is anticipated that there will be sufficient flexibility within the wind farm design to enable micro-siting to avoid environmental or heritage constraints additional to those identified in this ERD,” the documents say.

Another option in line with Fortescue’s target of “real zero emissions” included conversion of the company’s existing gas-fired Solomon Power Station to run on green ammonia/hydrogen, but the documents note this is “not economically viable” compared to wind, “due to the high cost of green ammonia
as a fuel.”

As things stand, the plan now is for “the installation of up to 100 wind turbines and associated infrastructure, with a target installed renewable energy capacity of approximately 2.1 Gigawatts (GW),” the documents say.

And the plans note that the actual power generation of the proposal may differ to the target capacity, depending on the efficiency of the turbine equipment once installed and throughout the life of the wind farm.

Pilbara Energy says the type of turbines used in the project could include the Nabrawind self erecting tower technology that Fortescue is testing out at a standalone pilot wind project right next door to the proposed Bonney Downs project.

The Nullagine Pilot Wind Farm, made up of 17 of the Nabralift turbines, is a stand-alone proof-of-concept project that will generate operational data and learning to inform future decision-making on larger developments, while also replacing the diesel generators at Christmas Creek mine.

According to the plans, work on the proposed Bonney Downs project is hoped to kick off this year, “following the receipt of all necessary approvals.” Construction activities are expected to take around 34 months, with electrical transmission infrastructure progressively commissioned over that time.

“The proposed lifespan of the Proposal (approximately 25-30 years) is based on the tenure duration of miscellaneous licences under the Mining Act 1978. However, the operational lifespan of the Proposal is anticipated to be longer as the wind resources are expected to be available at the Site for the foreseeable future,” the documents say.

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