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DECIBEL

The DECIBEL module makes it easy to calculate the noise impact of a wind farm project, interactively adjust the turbine layout and generate documentation for authorities and neighbours using the built-in country specific calculation models.

  • Rules
    Country Specific models
    DECIBEL includes many country specific models, making it easy to adhere to local regulations
  • Design with Iso-lines
    Use iso-lines on the map to see which neighbors will be affected by noise
  • Consider New and Old Turbines
    Take existing wind turbines into account when calculating the noise of planned turbines
  • Polygons or Points
    Define noise receptors as polygons or points
  • Reports
    Generate reports documenting the calculated noise impact for each noise receiver and turbine

Existing and new wind turbines can both be included, and it is possible to define Noise Sensitive Positions (spots) as well as areas described by polygons. For the latter, windPRO calculates the point on the polygon line with the highest noise impact and returns the coordinates and noise level for the point in the report. The noise calculation is based on the noise emission data at 10m height or at hub height (Lwa or octave data) of the wind turbine, usually found in the catalogue of windPRO; but it can also be entered manually.

The most commonly used propagation models are available and updated as necessary to meet the needs of the country of calculation. For each polygon/position, the maximum allowable noise level is automatically defined for the country of calculation (if known) or can be entered individually. The distance to the limit can be calculated so that it is possible to see how close to the allowed limit a dwelling is located. Also, it is possible to enter the ambient background noise level without turbines, if this is known, and then calculate the additional noise inflicted by the wind turbines.

It is possible to link a decibel calculation to a project layout, so a noise isoline map is automatically updated in the project window when turbines are moved on the map. This makes it easy to find the optimal layout with regards to noise impact. DECIBEL supports the use of reduced noise operation mode.

Many country-specific noise models included

The following noise propagation models are currently included in DECIBEL to carry out calculations:

  • ISO 9613-2 general, International Standard
  • ISO 9613-2, Germany
  • ISO 9613-2, UK
  • ISO 9613-2, France
  • ISO 9613-2, Norway
  • ISO 9613-2, Poland
  • ISO 9613-2, Finland
  • Denmark; The Guidelines of the Dept. of Environment, 2015 (including low Frequency)
  • Netherlands: “Reken- en meetvoorschrift windturbines”, 2011
  • Finland low frequency; Ympäristöhallinnon Ohjeita 2, 2014, Modellering av buller från vindkraftverk
  • Sweden: Ljud från landbaserade vindkraftverk, Naturvårdsverket, 2009.
  • Norway: Miljødirektoratet, 2015/2017
  • and all the former codes for Denmark, Netherlands, Germany and Sweden to allow recalculations

Necessary Input Data (Objects)

Please note that the objects are entered in the windPRO module BASIS.

Wind Turbine:

One or more wind turbines are entered (position and type). Usually, the wind turbine can be found in the wind turbine catalogue, which contains more than 1,000 different types and models. If no noise emission data, Lwa,ref, is given for the actual WTG in the catalogue, this data can be entered manually at the beginning of the calculation.

Noise Sensitive Areas:

Noise sensitive areas and/or positions are entered graphically on an on-screen map. For each area/position, a minimum distance to the nearest wind turbine and the maximum allowable noise impact in dB(A) can be entered.

Calculations Report

The calculation report generator includes the four following printout options:

Main Printout, with assumptions including a map rendering the wind turbines and noise sensitive areas. For each noise sensitive area, coordinates and calculated noise level are printed out for the point with the highest noise impact. Finally, a table is included which shows the distances between the wind turbines and the noise sensitive areas in a matrix.
Detailed Result: for each noise sensitive area or point the noise from each WTG and all noise parameters are listed. If the calculations are made for more than one wind speed then diagrams show the noise and noise requirements as a function of wind speed.
Maps: includes iso-noise lines for the spatial noise propagation from the site
Data to file: Export of noise Isolines in an Arc View GIS package format (Shape files) and to Google Earth (kmz).