Power developer’s noise assessment fails legal requirement: Queens U prof

Map of proposed turbine locations on Amherst Island: developer has failed to meet legal requirements, says Queens University professor emeritus

Association to Protect Amherst Island, June 5, 2015

Dr. John Harrison, Professor Emeritus, Queen’s University, and Vice-President of Research for APAI explains that the most recent noise assessment report is inadequate for the following reasons:

  • The “warranted sound power” quoted by Siemens and Hatch does not correspond to the declared apparent sound power specified by the technical standard IEC 61400-11.
  • The version of IEC 61400-11 used is now 10 years out of date. This was pointed out by APAI in its response to the second modification noise
  • The DANAK measurements were made in a neutral atmosphere (ground roughness length = 0.05 metres). The predictable worst case scenario (Section 6.4 of the MOECC 2008 regulations) will include turbulence, refraction, a higher ground parameter and a higher wind speed gradient. This has been ignored in the
  • The assessment uses ISO 9613-2. This was never intended for sound sources as much as 150 metres above ground. Its failings were noted over a decade ago by Vestas. In addition, the authors of ISO 9613-2 were aware of its limitations and added an uncertainty of ± 3 dBA. This has been ignored in the
  • In a letter to the project manager of the Falmouth MA wind energy development Vestas affirmed that under certain circumstances the sound power could be 8 dBA above its specified sound power. This supports APAI’s contention that in the worst case scenario the sound power of the Amherst Island turbines will exceed that specified by 8 Adding 8 dBA will render the sound pressure level at almost all homes (285 of 301 existing and vacant) within the study area above the MOECC 40 dBA limit at a wind speed of 6 m/s.

Consequently, APAI recommends that the Technical Review Committee reviewing the Windlectric Renewable Energy Approval documents and modification to those documents reject the Windlectric Inc. Noise Assessment Report submitted by Algonquin Power in support of Modification 4. MOECC should require Algonquin Power to submit a revised design and Noise Assessment Report that complies with IEC 61400-11, the uncertainty specified in Table 5 of ISO-9613-2 and the predictable worst case scenario specified in section 6.4 of the 2008 MOECC Noise Guidelines for Wind Turbines. MOECC should further require Algonquin Power to post the new submission on the EBR for a minimum of sixty days for public review and comment.

Read the full assessment: Attachment 1 to APAI Response to MOD 4 Acoustic Assessment-2.

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