Setting the Standards for Wind Turbine Noise Worldwide

Aercoustics Hosting International Wind Turbine Experts in Toronto

It’s clean, affordable, and endlessly renewable. It’s no surprise that wind power is one of the fastest growing methods of electrical generation in the world. But whether it’s here in Canada or abroad, the topic of wind energy can be divisive. But it may not be the turbine’s fault. If a wind project is not designed or tuned properly, turbines can be a noisy neighbour.

Accurately Measuring Wind Turbine Noise

Wind farms are unique installations and present different challenges when it comes to noise. Because the noise is dependent on the wind conditions, measurement of wind turbine noise at neighboring residents can be a complicated affair. Over the years, many different measurement techniques have been applied with the goal of quantifying wind turbine noise far away from the turbines. Many have been unsuccessful, but a few have honed the craft of measuring wind turbine noise accurately, repeatably and scientifically defensibly.

Equal Evaluation for Wind Turbines

With these new noisy neighbours in the rural landscape, the question of compliance with noise regulations has been a frequently-asked one. Evaluation of compliance post construction and in-situ is becoming ubiquitous in many jurisdictions. With many jurisdictions having to come up with their own methodology to deal with the lack of standardized methods, it has become a fractious regulatory landscape with increased uncertainty from all parties involved in the process. That’s why it is critical that we have international standards when it comes to noise measurements.

Setting International Standards for Wind Turbine Noise

This is where the IEC Standards Technical Committee 88 comes in. The committee reviews and sets all the worldwide electrical standards for wind turbines. Its focus is to ensure standards are up-to-date, explore new applications and make improvements to existing systems. Recently, a new sub-group has been formed specifically for creating a new technical specification for conducting far-field measurements of wind turbine noise.

This group, PT 61400-11-2, is comprised of global experts including:

  • Wind turbine noise manufacturers’ heads and experts on noise
  • Consultants who are involved in wind turbine noise including accredited measurement institutes
  • Project Developers who own and operate wind farms
  • Government funded research institutes

Aercoustics Joins International Committee for Wind Turbine Noise

I’m honoured to be the lone Canadian, and one of only two North Americans on the committee. This appointment came two years after Aercoustics became the first Canadian firm to be accredited to test for the IEC 61400-11 international standard for wind turbines. It was exciting to join the other members in these discussions. European countries have more mature wind industries and provide a great source of insight and knowledge. However, in recent years, the advent of green energy in Canada along with strict noise regulations has afforded us significant experience with measuring and quantifying this noise.

This month, the international delegation will gather in Toronto and Aercoustics is honoured to be hosting the committee. During the two day meetings in Toronto, the committee will be discussing progress towards a new technical specification covering measurement methodologies for wind turbines including details on measurement and analysis specifications for Sound Pressure Level, Tonality, Impulsivity, Amplitude modulation and other common quantities of interest with a goal of drafting a document by 2020.

The Need for International Standards

Standardizing long term noise measurements internationally is extremely important since it is a highly specialized type of noise measurement, and many jurisdictions do not have the experience or expertise to implement regulations or guidelines on measurement methods. This has resulted in a patchwork of regulatory requirements, which leads to inconsistent work being done, which in turn gives wind power a bad name.

The scope of the committee is incredibly large and aims to describe methods of measuring characteristics of wind turbine noise near dwellings such as the overall noise level, tonality, impulsivity and amplitude modulation among other metrics.

Getting Global: Technical Committee 88 Sets Other Standards

The international meetings cover a wide range of topics. One example is offshore wind turbines. The group is working on developing an International Standard for offshore wind turbines since they differ from onshore ones. The group will design requirements for floating offshore wind turbines which present particular constraints for rotor blades and for wind turbine towers and foundations. Another group works to update existing International Standards and projects while another team is dedicated to design requirements for gearboxes. I’m personally on a team that is dedicated to wind turbine acoustic noise measurement techniques.

Solid Standards Allow for Focus on Future Solutions

The knowledge gathered by the Committee is then published and shared internationally to be used as a guide. The committee’s combined expertise and research allows us to have consistent measurements made of wind turbines. This then allows the industry to move on from trying to decipher the difference between study results done using different methods and focus on solutions that reduce the impact at people’s homes.

Having International Standards provides peace of mind to everyone that the wind turbines being installed are safe, efficient and reliable and were built and installed with proper noise measurement techniques which will help to ensure the wind industry continues to grow and play a greater role in our energy needs.