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Wind turbines: noise is the issue on which Makara and Meridian cannot agree

Wellington.Scoop
by Lindsay Shelton
Prolonged negotiations between the small Makara community (population 843) and the electricity giant Meridian Energy (assets $7,197million) have failed to reach agreement on a central issue: noise.

The two sides have been having monthly meetings for a year and a half.

They meet as members of a community liaison group which was set up as part of the resource consent for the Makara wind farm. The group is small: two elected community representatives, one representative of the Makara Ohariu community board, one representative of Meridian Energy, and a convenor from the city council.

As the monthly meetings continue towards the end of a second year, the locals and Meridian keep discussing issues relating to the level of noise from the wind turbines.

How to agree on measuring the noise? How to get agreement on measuring noise levels before the 62 wind turbines are up and running, so that a “before and after’ comparison can be made? What to do if the two sides differ on their assessments of noise? The unresolved issues are complex.

From the first meeting, in October 2007, the local people asked for involvement in the noise-monitoring programme.

Meridian Energy wanted a draft report on monitoring to be kept confidential till it was finalized. The Makara representatives opposed secrecy. Their community would be affected by noise from the wind farm, but secrecy would stop them commenting on the draft report till after it was finalized.

Meridian’s wish for secrecy was also opposed by the Makara Guardians, who sought a copy of the draft in terms of the Official Information Act.

“Eventually” the council released the draft report. Both groups made submissions “albeit in tight timeframes” which were considered by the council’s expert noise reviewer Nigel Lloyd. Following his advice, the report was approved by the council.

Lengthy debate within the liaison group then moved to the number of monitoring points for pre-installation monitoring – the Makara residents wanted more than the report proposed and they expressed their concerns to Meridian’s noise expert, Paul Botha. Nigel Lloyd sided with Meridian. He believed sufficient monitoring had been provided for. He also believed that big new turbines would comply with resource consent conditions

The Guardians and the community representatives didn’t agree with the experts. They were concerned that there might not be a sufficiently accurate picture of pre-installation noise to enable meaningful assessment of any non-compliance once the turbines start generating power.

The Guardians asked for 16 more monitoring sites. Meridian agreed to assess them. Finally seven extra temporary sites were confirmed.

At subsequent meetings, there was debate on whether the noise emission report provided by the turbine manufacturers complies with the conditions of consent imposed by the Environment Court. The city council has been told: “While the experts appear to be confident that the turbines will comply and that any noncompliant [noise] occurrence will be able to be clearly identified, the community representatives … continued to have concerns about the information and assurances received.”

The issue of noise is causing anxiety for some people who live in Makara. They’re accustomed to a settlement where the peace and quiet is constant, and now they’re trying to understand the concepts of propeller noise and turbine noise at different speeds.

Their worries aren’t helped by the complexity of the issues over defining noise and then measuring it. How do you isolate wind noise, bird song noise, noise after rainfall? Not to mention the experts’ vocabulary which refers to scatter plots, regression curves, and amplitude modulation.

An “open day” on April 23 – members of the liaison group have been invited – could be the day when many of Meridian’s turbines start generating electricity.

Only when the massive propellers start turning will Makara’s residents be able to decide whether noise will continue to be an issue, or not.

Brooklyn is next:- plans for a new windfarm south of the Brooklyn wind turbine.

2 comments:

  1. John Third, 15. April 2009, 16:18

    This is a serious matter involving or at least significantly impacting on property rights.
    How can a State-owned business create noise that requires residents to keep windows closed in order to meet WHO standards for undisturbed sleep without mitigation or compensation??

     
  2. Nick Jennings, 15. April 2009, 18:23

    A thesis recently published, “Assessing Intrusive Noise and Low Amplitude Sound” by Robert Thorne, has this Abstract: “Annoyance due to relatively high levels of sound and noise, above 50 dB, has been well documented in noise assessment literature. The potential for annoyance or disturbance from low amplitude sound, below 50 dB to the threshold of an individual’s hearing, is not as well documented. The thesis presents a new approach to the measurement and assessment of intrusive noise and low amplitude sound. Acoustical and sound quality measures are integrated with measures of loudness, pitch, dissonance, and tonality to provide physical measures of sound. Individual amenity is assessed with respect to personal noise sensitivity and personal attitudes to sound in the environment, the environment itself and the perceived qualities of the audible sound. A decision-support methodology to integrate perceived noise with noise performance indicators, annoyance criteria, personal noise sensitivity and amenity is presented. A method for rating intrusive noise is derived. Designs for sound measurement and calibration instrumentation are described. Methods to measure and assess low amplitude sound are presented.” The thesis is 241 pages plus 60 pages of References, a Glossary and Annexes. Copies will be available, but the cost is not yet known.