Potential noise impacts have been assessed as part of the planning process. Our assessments have shown that neither Renewable Energy Park will exceed the wind farm noise standard recommended by the Environment Protection Authority (EPA).
During operation, we'll be required to demonstrate noise levels from the turbines meet the strict noise standard as predicted. The standard has been designed to ensure the noise from a wind farm is not intrusive for the average person. See below for more information about the EPA's standards.
Detailed operational noise modelling helped us predict noise levels across all wind speeds for our proposed 4.5 megawatt turbines. Noise generated by turbines changes with different wind speeds.
What we found
- One home was identified near Jim's Plain that could potentially be impacted by noise from the project.
- The highest predicted noise level at this home was 31 decibels. This is well below the criteria of 40 decibels that must not be exceeded.
Detailed operational noise modelling helped us predict noise levels across all wind speeds for the smallest (4.5 megawatts) and largest (12 megawatts) turbine sizes. We wanted to understand any potential change in noise.
What we found
- Smaller turbines: the highest predicted noise level at the closest residences on mainland Tasmania was 31 decibels. This is well below the criteria of 40 decibels that must not be exceeded.
- Larger turbines: the highest predicted noise level at the closest residences on mainland Tasmania was 37 decibels. This is below the criteria of 40 decibels that must not be exceeded.
How is wind farm noise assessed?
The wind farm standard NZS 6808:2010 Acoustics – Wind farm noise was used to provide methodologies and criteria for the noise assessments. This standard aims to minimise potential adverse impacts on people from noise generated by wind farms and provides methods for the prediction, measurement and assessment of sound.
This standard has been applied to other Tasmanian projects and was recommended to us by the EPA. Under this standard, the target criteria for wind farm noise is 40 decibels.
Examples of noise levels
130 decibels Jet aircraft at 50 metres
105 decibels Threshold of pain
95 decibels Pneumatic drill at 15 metres
60 decibels Busy general office
55 decibels Car at 64 kilometres an hour at 100 metres
35-45 decibels Wind farm at moderate wind speed 7 metres per second (based on sound level measurements from multiple homes near two Victorian wind farms, at distances 500-1,000 metres from the nearest turbine)
20-40 decibels Rural night-time background
Visual impact assessments for Jim's Plains and Robbins Island have helped us to understand what the wind turbines will look like from various surrounding viewpoints. We've developed photomontages that show the smallest and largest turbine we’re seeking approval for. In reality, a turbine in between the largest and smallest turbine will be installed, as the larger turbine won’t be available to meet our construction schedule.
All major wind turbine blade manufacturers finish their blades with a low-reflectivity treatment. This prevents a potentially annoying reflective glint and the possibility of a strobing reflection when the blades are spinning.
When the light level changes as the turbine blade rotates between the sun and the person looking at the blade, this is called shadow flicker. A conservative model of shadow flicker can be developed using the relative positions of the sun throughout the year, the wind turbines at the site, and the viewer. A shadow flicker assessment has been submitted in the approval documentation for the project.