Dragonfly Consulting: Using WINDCRANE in Wind Turbine Noise Assessments

Case Study - Dragonfly Consulting

 Dragonfly Consulting Operations Manager says: We use Windcrane products to log wind speeds and directions from a wind vane and anemometer attached to a 10m mast as well as collecting concurrent rain data for use as part of wind turbine noise impact assessments. Being able to access and download historic data remotely at any time is an incredible benefit for us. This data, along with noise levels recorded at the nearest Noise Sensitive Receptors, enable us to carry out Noise Impact Assessments of wind turbines using the guidance in ETSU-R-97 - Assessment & Rating of Noise from Wind Farms, in order to aid our clients in situations such as supporting planning applications for new wind turbine developments.

Dragonfly Consulting has participated in more than 200 wind power projects over the last 10 years, ranging from small turbines (15 m) to large installations with megawatt-scale turbines (>100 m).

They offer a wide range of consulting services, including noise impact assessments at wind turbine sites. These assessments typically take between 4-6 weeks to complete and require concurrent noise and weather monitoring.

• Dragonfly Consulting has used WINDCRANE monitoring systems to keep track of wind speed, wind direction and rainfall in many of their noise assessments;
• This data is analysed along with noise measurements taken at sensitive properties near project sites, to understand the behaviour of noise with increasing wind speeds;
• Dragonfly Consulting has ample experience liaising with local authorities and establishing the specific requirements for each project assessment.

ETSU-R-97 - Assessment & Rating of Noise from Wind Farms is the main guidance document used in the UK for wind turbine noise assessments. To analyse the potential impact of a wind turbine installation at a specific site, the assessment methodology requires the measurement of background noise at a wide range of wind speeds. ESTU-R-97 was developed by a dedicated Noise Working Group, referencing existing standards such as BS 7445 (Description and measurement of environmental noise) and BS 4142 (Methods for Rating and Assessing Industrial and Commercial Sound).

Wind Turbine Noise Assessments: WINDCRANE Applications

Following the methodology found in ESTU-R-97, Dragonfly Consulting uses mast-mounted anemometers and wind vanes to measure wind speed and direction at a height of 10 m, while noise monitoring equipment is used to concurrently measure decibel levels at the nearest noise-sensitive properties Using this data an assessment can be made to determine the impact of a proposed wind turbine or compliance of an existing turbine with the relevant noise level criteria at the nearest noise sensitive dwellings.

• Dragonfly Consulting pointed out the usefulness of the smart data analysis and filtering options on the LeNET web platform, which can be accessed remotely to visualise live and historic weather data from multiple sites.

• This feature is a major advantage for a consultancy firm that works with projects located throughout the UK.

In the case of none wind turbine noise impact assessments,; wind speed data is recorded to ensure noise levels adversely affected by wind can be removed from consideration in the assessment. This typically includes filtering data taken at average wind speeds of over 5 m/s as required in BS 7445 and BS 4142.

About Dragonfly Consulting

Dragonfly Consulting, based out of offices in York, Birmingham and London, is a multidisciplinary consultancy firm that specialises in acoustics, safety, and environmental issues predominantly in the construction industry. They have participated in over 200 wind power projects, conducting noise assessments for wind turbines of all scales, as well as type approval assessments for new wind turbines coming into the UK.