A 47-turbine wind farm in Tasmania's central highlands has been approved by the planning appeals tribunal, with a "narrow margin for compliance" over its potential noise emissions.
The St Patricks Plains wind farm is proposed by South Korean company Ark Energy for an area 10 kilometres south-east of Miena, near several highland lakes and small shack communities.
The Tasmanian Civil and Administrative Tribunal (TasCAT) approved the wind farm with conditions, following an appeal by the No Turbine Action Group (NTAG) on noise and height grounds.
Both grounds were unsuccessful, but while the matter was proceeding, the Environment Protection Authority (EPA) introduced a new wind farm noise policy.
It clarifies how wind farm noise is measured in Tasmania, including averaging noise over 10-minute intervals to better detect increases caused by issues like faulty equipment, and for comparison with background noise at quieter times.
The wind farm noise limit in Tasmania — as recorded at affected residences — was lowered from 40 decibels to 35 in 2020, and the state's overall policy is now in line with South Australia, Queensland and New South Wales.
St Patricks Plains is the first wind farm in Tasmania to be approved since the new policy was introduced.
Ark Energy general manager of development Donna Bolton said the company welcomed the approval and clarity around noise.
"Ark Energy considers the final noise conditions for St Patricks Plains wind farm, including a limit for non-involved dwellings of (35 decibels) and clarification about how compliance will be measured, to be reasonable," she said.
"It is consistent with best practice and will enable the wind farm to proceed."
The wind farm, which will have 231-metre-tall turbines, still requires Commonwealth approval.
Wind farm near multiple highland settlements
Environmental reports show there are 10 residents in the nearby settlement of Wilburville who could experience noise emissions of between 30 and 35 decibels.
The TasCAT decision notes there is a "narrow margin of compliance" with noise emissions, and a noise management plan will need to be developed before construction starts.
Modelling by consultants Marshall Day Acoustics suggested that any non-compliance could be addressed by having five of the towers operate at reduced power, although the report did not consider that this would be required.
Other nearby settlements include Penstock Lagoon, Shannon, Flintstone and Arthurs Lake.
NTAG has continued to question whether the wind farm will be able to comply with the noise policy, and foreshadowed litigation from nearby residents.
This occurred with the Bald Hills wind farm in Victoria, where the Supreme Court ordered the proponent to pay two neighbours $260,000 in damages over nuisance noise.
NTAG chair David Ridley said there was likely to be a "compliance and litigation period" if the St Patricks Plains wind farm was built, and he doubted that the company would be willing to take on the risk.
In an email to members, NTAG described the new policy as "good news for neighbours" and argued that Ark Energy's parent company — Korea Zinc — would be considering its options.
"Korea Zinc is now in the position of being permitted to build the St Patricks Plains Wind Farm under onerous noise conditions but not to exceed the nuisance noise requirements of the EPA," it reads.
"NTAG's view is the project is unlikely to be built because of the nuisance noise litigation risk and the Bald Hills precedent."
'Immediate' action needed for any noise issues
In its decision, TasCAT accepted that modelling from Ark Energy and the EPA showed that the 300-megawatt wind farm can meet the noise limits.
But if it does exceed limits, the EPA says "immediate action" will need to be taken, and selective wind turbine management will be needed.
"Selective (wind turbine) management, if needed, is only likely to be required in the short term and is not expected to be a significant imposition for the operation of the windfarm," EPA documents read.
Ark Energy attempted to have the New Zealand standard used for noise assessment — which does not have the same 10-minute averaged requirement — but this was rejected by TasCAT.
The wind farm attracted 76 public submissions in relation to noise, including concerns about the cumulative noise impact with the nearby Cattle Hill wind farm.
But the EPA did not find noise from the two wind farms would combine.
