4.0 DESCRIPTION OF SOURCES

Transcription

1 KEC Wind Project Environmental Noise Impact Assessment 18 July DESCRIPTION OF SOURCES 4.1 KEC Transformer Station Kruger Energy plans to build a transformer substation near Bowers Line and Vanedie Road as part of the Project. This substation will contain one 110 MVA transformer within the chainlinked fenced area (See Figure 2 & 6) The manufacturer s data sheet for this transformer indicates a maximum sound emission level of 76 (A) measured in accordance with the IEEE standard C This is the average sound pressure level measured at a distance of 2 m from the transformer cooling fans. The data sheet is attached in Attachment C. The noise contribution from the substation is calculated using the DataKustik CadnaA version 3.7 environmental noise prediction software. The calculations are based on established prediction methods approved by the MOE: ISO standard entitled Acoustics Attenuation of sound during propagation outdoors Part 2: General method of calculation. For this analysis, the noise contribution from the substation was added to the noise contributions of the wind turbines to assess the total cumulative effect of the Project. IEEE C standard, Distribution, Power, and Regulating Transformers has been used to develop the noise modelling parameters. This standard outlines a nearfield sound level specification for the transformer. Each transformer in this study is modelled having five radiating area sources. Four of which are representative of the sides of the transformer, while the fifth represents the top. The vertical area sources have been modelled to have a maximum source height of 4.33 m, which is the overall height of the acoustical vertical area enveloping the transformer. ATTACHMENT C provides the manufacturer s drawings outlining the physical height of the transformer. This modelling protocol is in accordance with the IEEE standard.

2 KEC Wind Project Environmental Noise Impact Assessment 18 July Potential Sources of Noise Transformer noise is comprised of casing noise emitted from the operating transformer itself and cooling fan noise. Transformer noise has a pronounced audible tonal quality and has been considered in the analysis that follows Transformer Station Noise Emission Rating The acoustic measurement surface of a transformer is m long by 6.70 m wide by 4.33 m high. The CadnaA acoustic model surface is taken to be 0.3 m from the transformer tank or transformer cooling fan whichever is more outboard. The calculated sound power level for each vertical surface is based upon the area of the acoustic measurement surface. The horizontal area of the top of the transformer is modelled in accordance with the IEEE standard for large transformers; in which the top is representative of 25% of the total vertical measurement surface area. Therefore, the calculated sound power level for the top of the transformer is based on m 2. The tables below outline the sound power spectrum that was used for each transformer s four vertical area sources and top horizontal surface. Table 3: Transformer Average Sound Pressure the measurement surface Octave Band Center Freq. (Hz) Chatham Transformer As per IEEE standard C (spectrum in ) 31.5 Hz Hz 125 Hz 250 Hz 500 Hz 1k Hz 2k Hz 4k Hz 8k Hz A Table 4: Calculated Sound Power for Transformer Faces Octave Band Center Freq. (Hz) Transformer Northeast Long Face (10.56m x 76 A) (spectrum in ) Transformer Southwest Long Face (10.56m x 76 A) (spectrum in ) Transformer Northwest Short Face (6.7m x 76 A) (spectrum in ) Transformer Southeast Short Face (6.7m x 76 A) (spectrum in ) Transformer Top Face (37.39 m 76 A) spectrum in 31.5 Hz A 63 Hz 125 Hz 250 Hz 500 Hz 1k Hz 2k Hz 4k Hz 8k Hz A A 92.6 A 90.6 A 90.6 A 91.7 A

3 KEC Wind Project Environmental Noise Impact Assessment 18 July The above listed spectrums correspond to the total sound power level for each of the vertical area sources used to model the transformer for the typical worst case operating scenario as zero to full load with all cooling equipment operating. It should be noted that this spectrum does not account for tonality. Thus, a 5 penalty, consistent with MOE guideline NPC 104, has been included in this analysis. Consequently, the overall source sound power including tonality was amended to be 97.6 (A) for the northeast or southwest face and 95.6 A for the northwest or southeast face for purposes of this analysis to maintain additional conservancy in the model results. Similar to the vertical face sources, this spectrum does not account for tonality from the top face. Thus, following the same methodology noted above, a 5 penalty was included in this analysis. This creates an overall source sound power level for the top of the transformer, including tonality, of 96.7 (A). The tonal adjusted value of 96.7 (A) is utilized in this analysis to maintain additional conservancy in the model results. 4.2 Port Alma Transformer Substation The Port Alma Substation is currently operating on Simpsons Line near KEPA turbine T9. This substation has one 110 MVA transformer with a 76 A maximum noise rating, which is the same as the planned transformer for the KEC substation. All noise calculations for this ENIA include the noise contribution from both the KEPA and KEC substations. 4.3 Blasting Noise and Vibration Although not certain at the time of writing, given the proximity of bedrock to the ground surface at KEC, it is very unlikely that Kruger will need to perform blasting operations during the construction of the Project. Should blasting be required, noise and vibration levels from any required blasting activities will be required to meet the MOE guideline as set out in MOE publication NPC 119. Based upon NPC 119, if the entity in charge of the blasting operation carries out routine monitoring of peak pressure level, the peak pressure level limit for sound concussion resulting from blasting can be 128. If the routine monitoring is not carried out, then the peak pressure level limit for sound concussion from blasting should be 120. Consistent with NPC 119, if the entity in charge of the blasting operation carries out routine monitoring of vibration, the peak particle velocity limit for vibration resulting from blasting can be 1.25 cm/s. If routine vibration monitoring is not carried out, then the peak particle velocity limit for vibration from blasting should be 1.00 cm/s.

4 KEC Wind Project Environmental Noise Impact Assessment 18 July Wind Turbine Generators The Project will utilize Siemens model SWT , model SWT Low Noise, model SWT , and model SWT Low Noise wind turbines. These are turbines designed for medium and high-wind sites and are well suited for energy extraction in the Chatham Kent area. As evidenced by the model classification, the Siemens SWT has a nominal rating of 2.3 MW. It has a three-bladed upwind rotor that drives an electric asynchronous generator via a planetary gear. Each blade has a length of 49 metres. The Siemens SWT has a nominal rating of 2.3 MW. It has a three-bladed rotor that drives an electric asynchronous generator via a planetary gear. Each blade has a length of 45 metres. The low noise model turbines are standard wind turbines SWT and SWT which have been modified to maintain noise emission below a certain threshold level. The KEC low noise model turbines will maintain the noise levels listed in Table 6 and Table 8. The Siemens turbine is a variable speed, pitch regulated upwind turbine with active yaw control and three blade rotor. A separate hydraulic pitch cylinder for each blade is situated within the nacelle. The generator and associated gearing are housed in a nacelle that is mounted on an 80 m high tower. The nacelle units are equipped with yaw motors to turn the nacelle into the wind. Additional information on the Siemens turbines is provided in ATTACHMENT B. Turbine coordinates are listed in Table Potential Sources of Noise There are several sources that contribute to the sound emitted by a typical wind turbine. As the rotating blades of the turbine extract power from the air-stream, the blades experience lift and drag forces. These forces generate sound, much in the same manner as a rotating propeller or fan also known as aerodynamic noise. The sound is predominantly tonal, with the fundamental sound established by the blade passage frequency, which is the product of the total number of blades and the rotation rate. For the proposed turbines the blade passage has a maximum frequency of 1 Hz. This is well below the audible frequency range (i.e., 20 Hz to 16,000 Hz). INFRASOUND Sounds with frequency contents below 20 Hz are referred to as infrasound. There are many other sources of infrasound such as those generated by winds, waterfalls, and the sound of waves breaking on the beach. Measurements at 200 m from typical units have shown that the infrasound levels are well below the level of perceptibility [1], [2]. As noted above, there are no non-participating Points of Reception within 400 m of a wind turbine and thus the potential effect of infrasound is not anticipated.

5 KEC Wind Project Environmental Noise Impact Assessment 18 July AMPLITUDE MODULATION Perceptible sounds are generated predominantly by mechanical bearings, the electric generator and a characteristic swoosh which is essentially higher frequency broadband noise that is amplitude modulated at a low frequency [3]. In contrast to the first-generation wind turbines, some 30 years ago, innovations in blade geometry, materials, and mechanical systems have significantly lowered the sound power levels of present generation wind turbines. A recent study of wind turbine noise amplitude modulation [3] by the University of Salford, UK found that amplitude modulation occurs between 7% and 15% of the time, but the causes of amplitude modulation are still open to debate therefore the causes are not fully understood and that amplitude modulation cannot be fully predicted by current state of the art. The Salford study concludes that further research is recommended to improve understanding of amplitude modulation. The MOE does not recommend a penalty be applied to wind turbine noise due to amplitude modulation, ref [17]. WIND SHEAR EFFECTS Vertical Wind shear, sometimes referred to as wind shear or wind gradient, is a vertical difference in wind speed and direction over a relatively short distance in the atmosphere. For acoustic purposes, vertical wind shear is used as a measure of the change in wind speed at various vertical heights above ground level. Wind shear has been accounted for in the KEC noise assessment by adjusting the standard neutral stability wind turbine emission to an emission which accounts for the site specific average summer nighttime wind shear exponent. This approach is consistent with the recommendations of the MOE s Noise Guidelines for Wind Farms [17]. WIND TURBINE TONALITY As outlined in the Windtest measurement report (Attachment B), for all wind speeds the tonal audibility ΔL a,k is a negative number. This means that the tonality is below the tonal audibility criterion curve L a. Therefore, tones are not audible and penalties are not appropriate. CSA clearly states how to measure tonal audibility but does not specify how to apply tonal penalties. Aercoustics recommends that ISO be used to apply tonal penalties for wind turbines because it is an accountable international standard that is a good extension of CSA Therefore, based on the Windtest reports along with ISO , a wind turbine tonal penalty has not been applied for the KEC Wind Project.

6 KEC Wind Project Environmental Noise Impact Assessment 18 July KEC Wind Turbine Noise Emission Rating The SWT has a rotor speed of 6 to 16 rpm therefore the resultant blade passage frequency is 0.30 Hz. Siemens has provided Kruger with noise warrantees for the Siemens wind turbines for wind speeds of 6ms/ to 10m/s with a quality assurance of +/- 1 A. See Table 5, Table 6, Table 7, and Table 8 below and Attachment B. Typical noise emission spectrums for 6m/s, 7m/s, 8m/s, 9m/s and 10m/s wind speed, for wind at a 10m reference height was provided by Siemens (see Attachment B). Table 5, Table 6, Table 7, and Table 8 presents all the turbine noise emission spectrums that were used in the noise assessment calculations. Table 5: SWT , Sound Power wind speeds from 6m/s to 10m/s Siemens SWT Electrical Rating: 2.3 MW Hub Height (m): 80m Wind Shear coefficient: 0.30 Octave Band Sound Power Level () Manufacturer s Emission Levels Adjusted Emission Levels Wind Speed (m/s) Frequency (Hz) Total A Table 6: SWT Low Noise model, Sound Power wind speeds 6m/s to 10m/s Siemens SWT , Low noise model Electrical Rating: 2.2 MW Hub Height (m): 80m Wind Shear coefficient: 0.30 Octave Band Sound Power Level () Manufacturer s Emission Levels Adjusted Emission Levels Wind Speed (m/s) Frequency (Hz) Total A

7 KEC Wind Project Environmental Noise Impact Assessment 18 July Table 7: SWT , Sound Power wind speeds from 6m/s to 10m/s Siemens SWT Electrical Rating: 2.3 MW Hub Height (m): 80m Wind Shear coefficient: 0.30 Octave Band Sound Power Level () Manufacturer s Emission Levels Adjusted Emission Levels Wind Speed (m/s) Frequency (Hz) Total A Table 8: SWT low noise model, Sound Power wind speeds 6m/s to 10m/s Siemens SWT , low noise model Electrical Rating: 2.2 MW Hub Height (m): 80m Wind Shear coefficient: 0.30 Octave Band Sound Power Level () Manufacturer s Emission Levels Adjusted Emission Levels Wind Speed (m/s) Frequency (Hz) Total A The site specific average summer nighttime wind shear exponent was provided by Helimax, wind engineering consultants for Kruger. Attachment B also presents a detailed noise measurement report by Windtest GmbH for a single Siemens SWT wind turbine according to IEC acoustic measurement standard. This turbine is identical in all respects to the SWT planned to be deployed on the project, with the exception of the rotor (blade length). The Windtest report for the 101 turbine is not yet available as per correspondence from the manufacturer, but will be provided as soon as it is made available. Kruger s agreement with Siemens includes a guarantee on the sound power level associated with the four turbine models being provided.

8 KEC Wind Project Environmental Noise Impact Assessment 18 July Table 9: Wind Turbine Locations KEC Wind Turbines UTM Coordinates Identifier Equipment Make & Model X (m) Y (m) Remarks T45 Siemens SWT T46 Siemens SWT low noise model MW T47 Siemens SWT T48 Siemens SWT low noise model MW T49 Siemens SWT T50 Siemens SWT T51 Siemens SWT T52 Siemens SWT T53 Siemens SWT T54 Siemens SWT T55 Siemens SWT low noise model MW T56 Siemens SWT T57 Siemens SWT T58 Siemens SWT T59 Siemens SWT T60 Siemens SWT T61 Siemens SWT low noise model MW T62 Siemens SWT low noise model MW T63 Siemens SWT low noise model MW T64 Siemens SWT low noise model MW T65 Siemens SWT low noise model MW T66 Siemens SWT low noise model MW T67 Siemens SWT low noise model MW T68 Siemens SWT T69 Siemens SWT T70 Siemens SWT low noise model MW T71 Siemens SWT low noise model MW T72 Siemens SWT low noise model MW T73 Siemens SWT low noise model MW T74 Siemens SWT T75 Siemens SWT T76 Siemens SWT low noise model MW T77 Siemens SWT low noise model MW T78 Siemens SWT T79 Siemens SWT T80 Siemens SWT

9 KEC Wind Project Environmental Noise Impact Assessment 18 July KEC Wind Turbines UTM Coordinates Identifier Equipment Make & Model X (m) Y (m) Remarks T81 Siemens SWT T82 Siemens SWT T83 Siemens SWT T84 Siemens SWT low noise model MW T85 Siemens SWT low noise model MW T86 Siemens SWT T87 Siemens SWT T88 Siemens SWT T_GG01 Enercon E Swanton Windfarm T_GG02 Enercon E Swanton Windfarm T_GG03 Enercon E Swanton Windfarm T_GG04 Enercon E Swanton Windfarm T_GG05 Enercon E Swanton Windfarm Swanton Wind Farm GenGrowth Renewable Inc. is building a five turbine wind farm near the northeast corner of the Kruger s KEC proposed wind farm. The total noise impact assessment on Kruger points of reception includes the noise impact from all transformers and all wind turbines, including the noise impact from all GenGrowth turbines from the proposed Swanton wind farm. Noise emissions and turbine locations for this assessment is based on the data from the Swanton Wind Farm Noise Report, prepared by Boralex. Table 10: Swanton Wind Farm Sound Power wind speeds 6m/s to 10m/s for Enercon E82 Enercon E82 Electrical Rating: 2.0 MW Hub Height (m): 78m Wind Shear coefficient: 0.30 Octave Band Sound Power Level () Manufacturer s Emission Levels Adjusted Emission Levels Wind Speed (m/s) Frequency (Hz) Total A

10 KEC Wind Project Environmental Noise Impact Assessment 18 July NOISE ASSESSMENT RESULTS 5.1 KEC Transformer Station Impact Assessment DataKustik CadnaA environmental noise model generated the worst-case results shown in Table 11. These results include sound power levels that account for tonality and contributions of the wind turbines. As indicated in the Table, and applying the conservative application of Class 3 (rural) areas to all Points of Reception, the transformers are not expected to meet the applicable noise guidelines without the application of abatement measures. The receptors identified in Table 11 are the worst-case receptors, closest to the KEC transformer. Table 11: Total Noise Impact without Transformer Noise Controls, 6m/s wind speed Receptor Description Distance to Transformer (m) Calculated Sound Level (A) Allowable Level R storey residence, (on Vanedie Road) A 40.0 A R storey residence, (on Vanedie Road) A 40.0 A Transformer Noise Controls In order to satisfy the sound level limits at the receptor locations, a local acoustical barrier was applied as shown on Figure 6, 6B, 6C. The barrier would encompass the area proximal to the north, west, and south faces of the transformers, leaving the east and top faces exposed for cooling. The barrier would have a nominal height of at least 5.0 m (at least 0.7m above the top surface of the core of the transformer, see Figure 6C). The acoustical barrier would be constructed using Durisol sound blocks, or equivalent. The acoustical wall should be free of any gaps, openings, or discontinuities, and should have a surface weight of at least 4lb/ft 2 (20kg/m 2 ). Furthermore, the barrier should be an absorptive barrier to ensure that reflections are not a concern Cumulative Noise Effect Based upon the above design considerations, the acoustical barrier was inserted into the to DataKustik CadnaA environmental noise model. The model generated results as shown in Table 12. The resultant predicted worst-case conditions, are applied against the Class 3 (rural) designation, and account for transformer tonality and contributions from all wind turbines including neighbouring GenGrowth proposed wind turbines and KEPA turbines. Table 12: Cumulative Noise Impact with Transformer Barriers, 6 m/s wind speed Receptor Description Distance to Transformer (m) Calculated Sound Level (A) Allowable Level R storey residence, (on Vanedie Road) A 40.0 A R storey residence, (on Vanedie Road) A 40.0 A

11 KEC Wind Project Environmental Noise Impact Assessment 18 July Wind Turbine Impact Assessment The noise impact at 427 receptor dwellings has been predicted using a formula based on ISO Part 2; consistent with the MOE s modelling requirements. The locations and sound power levels of all the wind turbine sources, the transformer station sources and the location of the receptors were integrated into a master data file. Noise was predicted based on the following noise modelling protocol: Average Summer Nighttime Temperature = 19C Average Summer Nighttime Humidity = 60% G = 0.70 global ground attenuation factor Sound Level Limit = m agl, i.e. precision to 1/10th of decibel Turbine noise emission adjusted to KEC specific conditions of average summer nighttime wind shear exponent =0.30 Analysis to include only turbines within 5km of a receptor for those receptors whose closest Chatham turbine is within 1.5km Two storey dwelling = 4.5m receptor center of dwelling Single storey dwelling = 1.5m receptor 30m from building face of dwelling The noise assessment was based on all of the recommended procedures outlined in the MOE s Noise Guidelines for Wind Farms, October 2008 ref [17], except that the calculated attenuation due to atmospheric absorption was based on site specific average summer nighttime temperature and humidity provided by Helimax. This is consistent with the intent of the MOE s noise guideline which is to determine maximum rated output of the wind farm and reflect the principle of predictable worst case noise impact. The highest noise level for each receptor, which represents the worst-case prediction, is outlined below in the assessment summary Table 14. The programme computes the octave band levels at the receptors from all the sound sources, including the transformers. The resultant A-weighted sound pressure levels are then transferred to the site map that shows both source and receiver locations. The detailed maps showing the locations of the wind turbines, transformer station, and the receptors are found in Figure 3. Some of the residences of the landowners that have entered into an Option to Lease Agreement with Kruger were considered participating and excluded from further evaluation. This is consistent with the MOE Guidance Note contained in Attachment A. Maximum sound levels have been predicted at all 427 dwellings and detailed calculations are provided in Attachment D. The maximum predicted sound levels at all non-participating receptors are predicted to be within the MOE environmental noise limits for Class 3 (rural) areas.

12 KEC Wind Project Environmental Noise Impact Assessment 18 July Wind Turbine Summary Tables The sound power emitted by the wind turbines and transformer station, as well as their location with respect to the receptors determines the sound pressure levels induced by the operation of all Project components. The acoustic power of each wind turbine as provided by the manufacturer is shown in ATTACHMENT B. The total noise impact at each receptor, including all wind turbines and transformer stations, has been summarized in the noise assessment summary table (Table 14). The predicted sound pressure levels, as well as the sound level limits as set by either MOE NPC-205 or NPC 232, are included for easy reference. The noise impact from the simultaneous operation of all wind turbines and transformers is less than or equal to the sound level limit associated with NPC 232 (i.e., 40.0 A). RPZ2065 and RPZ3328 are participating receptors whose dwellings will be demolished and rezoned agricultural. RPZ2064 is a participating receptor zoned agricultural whose dwelling will be converted to a storage building. The noise assessment summary table presents the predicted sound levels for all 427 dwellings that are located within 1,500m of a KEC wind turbine. It should be noted that receptor numbers are not perfectly contiguous due to various changes to the participating/non-participating stakeholder list over the course of project design activities and screening of all receptors within 2,000 meters of the proposed Chatham turbine locations. The closest non-participating receptor dwelling is Rs2590 which is single storey dwelling located 554m from Chatham turbine # 86. All other non-participating receptor dwellings are more than 554m from a proposed Chatham wind turbine. Table 13: Summary Table Legend T45 to T88 = Chatham turbine # 45 to Chatham turbine #88 T1 to T44 = Port Alma turbine # 1 to Port Alma turbine #44 T_GG01 to T_GG05 = GenGrowth Swanton windfarm turbine # 1 to #5 RP2166 (coloured red) = participating Chatham residential receptor # 2166 R2034(coloured black) = nonparticipating Chatham residential receptor # 2034 RN2130(coloured black) = nonresidential Chatham receptor #2130 Rs1968(coloured black) = nonparticipating Chatham single storey residential receptor #1968 Subscript "s" designates single storey dwelling.n designates point of reception 30m north of dwelling face, 1.5m above ground.e designates point of reception 30m east of dwelling face, 1.5m above ground.s designates point of reception 30m south of dwelling face, 1.5m above ground.w designates point of reception 30m west of dwelling face, 1.5m above ground

13 KEC Wind Project Environmental Noise Impact Assessment: 18 July Table 14: Wind Turbine and Transformer Noise Assessment Summary Point of Reception ID Receptor Height Receptor Description GPS co-ords Distance to nearest Chatham Turbine (m) Turbine ID Calculated Sound Pressure Level (A) at Selected Windspeeds (m/s) Sound Level Limits (A) at Selected Windspeeds (m/s) Background Level <= <= NPC 232 R Residence T Yes R Residence T Yes R Residence T Yes R Residence T Yes R Residence T Yes R Residence T Yes R Residence T Yes R Residence T Yes R Residence T Yes R Residence T Yes R Residence T Yes R Residence T Yes R Residence T Yes R Residence T Yes R Residence T Yes R Residence T Yes R Residence T Yes R Residence T Yes R Residence T Yes R Residence T Yes R Residence T Yes R Residence T Yes R Residence T Yes R Residence T Yes R Residence T Yes R Residence T Yes R Residence T Yes R Residence T Yes R Residence T Yes Compliance with Limit (Yes/No)

14 KEC Wind Project Environmental Noise Impact Assessment: 18 July Point of Reception ID Receptor Height Receptor Description GPS co-ords Distance to nearest Chatham Turbine (m) Turbine ID Calculated Sound Pressure Level (A) at Selected Windspeeds (m/s) Sound Level Limits (A) at Selected Windspeeds (m/s) Background Level <= <= NPC 232 R Residence T Yes R Residence T Yes R Residence T Yes R Residence T Yes R Residence T Yes R Residence T Yes R Residence T Yes R Residence T Yes R Residence T Yes R Residence T Yes R Residence T Yes R Residence T Yes R Residence T Yes R Residence T Yes R Residence T Yes R Residence T Yes R Residence T Yes R Residence T Yes R Residence T Yes R Residence T Yes R Residence T Yes R Residence T Yes R Residence T Yes R Residence T Yes R Residence T Yes R Residence T Yes RZ Zoned Agriculture T Yes R Residence T Yes R Residence T Yes Compliance with Limit (Yes/No)