Noise guidelines for wind farms
This document describes sound level limits and specifies the information proponents are required to submit to the Ministry of the Environment and Climate Change when seeking approval for a proposed land-based Wind Facility.
Legislative Authority:
Environmental Protection Act, R.S.O. 1990, c. E.19, Ontario Regulation 359/09
Original Publication Date:
October 2008
Last Revision Date:
May 2016
PIBS 9900e
Guideline references
This guideline references the following publications:
- NPC-300, “Environmental Noise Guideline: Stationary and Transportation Sources Approval and Planning,” August 2013, Ministry of the Environment, PIBS 9588e.
- NPC-206, “Sound Levels due to Road Traffic,” Ontario Ministry of the Environment, as amended.
- CAN/CSA-C61400-11-07, “Wind Turbine Generator Systems – Part 11: Acoustic Noise Measurement Techniques.”
- CAN/CSA-IEC 61400-11:13, “Wind Turbines – Part 11: Acoustic Noise Measurement Techniques.”
- ISO 9613-1, “Acoustics – Attenuation of sound during propagation outdoors – Part 1: Calculating of the absorption of sound by the atmosphere.”
- ISO 9613-2, “Acoustics-Attenuation of sound during propagation outdoors – Part 2: General method of calculation.”
- ANSI/IEEE C57.12.90, “Standard Test Code for Liquid-immersed Distributing Power, and Regulating Transformers.”
- “Technical Guide to Renewable Energy Approvals,” 2013, PIBS 8472e, as amended.
Definitions
For the purpose of this document, the following definitions apply. Several of the definitions are based on Publication NPC-300, Reference [1], but have been modified to apply in the context of wind facilities.
- “Approval”
- means a Certificate of Approval issued under section 9 of the Environmental Protection Act, a Renewable Energy Approval issued under section 47.5 of the Environmental Protection Act, or an Environmental Compliance Approval issued under Part II.1 of the Environmental Protection Act.
- “Approved Wind Facility”
- means a wind facility for which an approval has been issued.
- “Campsite or Campground”
- means a portion of a property that is used for camping at which overnight accommodation is provided by or on behalf of a public agency or as part of a commercial operation.
- “Class 1 Area”
- means an area with an acoustical environment typical of a major population centre, where the background sound level is dominated by the activities of people, usually road traffic, often referred to as “urban hum.”
- “Class 2 Area”
- means an area with an acoustical environment that has qualities representative of both Class 1 and Class 3 areas:
- sound levels characteristic of Class 1 during daytime (7:00 to 19:00 or to 23:00 hours); and
- low evening and night background sound level defined by natural environment and infrequent human activity starting as early as 19:00 hours (19:00 or 23:00 to 7:00 hours).
- “Class 3 Area”
- means a rural area with an acoustical environment that is dominated by natural sounds having little or no road traffic, such as the following:
- a small community;
- agricultural area;
- a rural recreational area such as a cottage or a resort area; or
- a wilderness area.
- “Dwelling”
- has the same meaning as in Ontario Regulation 359/09.
- “Inaccessible Vacant Lot”
- has the same meaning as in Ontario Regulation 359/09.
- "Ministry"
- means the ministry of the Government of Ontario responsible for the Environmental Protection Act and includes all officials, employees, or other persons acting on its behalf.
- “Noise Impact Assessment Report”
- means a report prepared in accordance with this document for a proposed wind facility.
- “Noise Sensitive Institutional Purpose Building”
- means a building used for an institutional purpose, including an educational facility, a child care centre, a hospital, a health care facility, a shelter for emergency housing, a community centre, a place of worship or a detention centre.
- “Noise Sensitive Land Use”
- means:
- a property on which a building or structure that contains one or more dwellings is located and includes hotels, motels and legal nonconforming residential uses;
- a property on which a noise sensitive institutional purpose building is located; or
- a portion of property that is used as a campsite or campground.
- “Noise Sensitive Zoned Lot”
- means a property that has been zoned to permit a building or structure mentioned in clauses (a) or (b) of the definition for noise sensitive land use and that is either:
- currently vacant; or
- has an existing land use that is not a noise sensitive land use.
- “Participating Receptor”
- means the location of one or more receptors at a noise sensitive land use or a noise sensitive zoned lot where noise from a wind facility is received as further specified in Section 6.3, if any part of the wind facility will be located on that property once the facility is installed, constructed or expanded in accordance with the approval.
- “Planned Wind Facility”
- means a wind facility that has not received an approval but is in the process of being planned. This includes any wind facilities that have been proposed to be constructed or installed and,
- in respect of which notice of the proposal for the issue of an approval has been posted on the Environmental Registry and in respect of which the proposal has not been approved or refused under the Environmental Protection Act;
- are identified in an environmental screening report or environmental review report that is made available under the Environmental Screening Process pursuant to Ontario Regulation 116/01; or
- are identified in a draft site plan that is made available or distributed in accordance with section 54.1 of Ontario Regulation 359/09, unless the proponent of that wind facility did not apply for an approval within 18 months of issuing the draft site plan.
- “Point of Reception”
- means the location of one or more receptors at a noise sensitive land use or a noise sensitive zoned lot where noise from a wind facility is received as further specified in Section 6.3, but does not include a location that the setback in subsection 54(1) of Ontario Regulation 359/09 does not apply to, other than in the situation specified in Section 6.4.6.2.
- “Sound Power Level”
- has the same meaning as in Ontario Regulation 359/09. For details see section 1 of Ontario Regulation 359/09.
- “Switching Station”
- means a collection point for the outputs of the wind turbine generators.
- “Transformer Substation”
- means a central facility comprised of power transformer(s) and associated equipment such as cooling fans for transforming the electrical outputs from the wind turbine generators to a higher voltage for input to the grid transmission system. Transformer substations are significant noise sources.
- “Wind Facility”
- has the same meaning as in Ontario Regulation 359/09.
Scope
In assessing an application for approval for a proposed land-based wind facility, the ministry considers noise impacts.
The purpose of this document is to describe the applicable sound level limits and to specify the information proponents are required to submit to the ministry when seeking approval for a proposed land-based wind facility. This document has been developed to provide consistency in the submissions and to streamline the review and approval process. Accordingly, the information contained herein is intended to provide uniformity in the planning of wind facilities in Ontario.
Proponents of wind facilities are to prepare and submit to the ministry a noise impact assessment report that includes details of the wind turbine design and operation, location of the wind turbine(s) within the specific site and surrounding area, as well as a summary of compliance with the applicable sound level limits. If applicable, the noise impact assessment report must also include similar details of the transformer substation(s) used for transforming the power from the wind turbine units. This document defines a template for the noise impact assessment report to be submitted to the ministry.
This document also provides information on the assessment of the combined noise impact produced by the proposed wind facility in combination with the noise impact of approved wind facilities or planned wind facilities.
An application for an approval of a proposed new wind facility, or an application for an amendment to an approval for an approved wind facility, that is submitted to the ministry on or after May 1, 2016, will be assessed in accordance with this document.
An application for an approval of a proposed new wind facility, or an application for an amendment to an approval for an approved wind facility, that was submitted to the ministry before May 1, 2016, and that was prepared in accordance with the previously applicable document, “Interpretation for Applying MOE NPC Publications to Wind Power Generation Facilities, Noise Guidelines for Wind Farms,” October 2008, PIBS 4709e (i.e. 2008 Noise Guidelines for Wind Farms), will be assessed in accordance with that document.
In addition, it should be noted that the Director retains the discretion to require that additional studies be provided where warranted and to determine what, if any, additional requirements to impose in any individual case.
3.1 Transition rules
A proponent may choose to implement all aspects of this document regardless of the Transition Rules below.
3.1.1 Wind facilities approved under the 2008 Noise Guidelines for Wind Farms
If an application for an amendment to an approval is submitted for a wind facility that was approved under the 2008 Noise Guidelines for Wind Farms, the two transition rules noted below apply to the change, provided the application does not include any of the following changes:
- a change to the location of a wind turbine or transformer substation;
- an increase to the octave-band sound power levels (linear weighted) of a wind turbine, as calculated in accordance with the standard specified in paragraph 1 of subsection 1(6.1) of Ontario Regulation 359/09, unless there would be no resulting increase to the sound levels at any point of reception within 1,500 metres (m) of the wind turbine;
- an increase to the acoustic emissions of a transformer substation, as calculated in accordance with ANSI/IEEE C57.12.90, Reference [7], unless there would be no resulting increase to the sound levels at any point of reception within 1,500 m of the transformer substation; or
- the addition of one or more wind turbine(s) or transformer substation(s).
Transition Rule for Octave Band Frequencies: Section 6 of this document requires that the noise assessment for a wind facility use octave band frequencies ranging from 31.5 Hz to 8,000 Hz. For changes to wind facilities described in Section 3.1.1, the octave band frequency range that applies is 63 Hz to 8,000 Hz.
Transition Rule for Ground Factor Values: This document requires that the noise assessment for a wind facility use the ground factor values as specified in Section 6.4.10 c). For changes to wind facilities described in Section 3.1.1, the ground factor values that apply are as follows:
For Class 2 and 3 Areas, the assessment of wind turbines must use ground factor values not exceeding the following:
Gs = 1.0
Gm = 0.8
Gr = 0.5
Where: Gs is the ground factor for the source region,
Gm is the ground factor for the middle region, and
Gr is the ground factor for the receiver region.
Alternatively, a global ground factor value not exceeding 0.7 may be used.
3.1.2 Wind facilities approved prior to the 2008 Noise Guidelines for Wind Farms
If an application for an amendment to an approval is submitted for a wind facility that was approved before the 2008 Noise Guidelines for Wind Farms applied, the noise modelling approach and parameters that applied at the time the approval was issued will continue to apply to the change, provided the application does not include any of the following changes:
- a change to the location of a wind turbine or transformer substation;
- an increase to the octave-band sound power levels (linear weighted) of a wind turbine, as calculated in accordance with the standard specified in paragraph 1 of subsection 1(6.1) of Ontario Regulation 359/09, unless there would be no resulting increase to the sound levels at any point of reception within 1,000 m of the wind turbine;
- an increase to the acoustic emissions of a transformer substation, as calculated in accordance with ANSI/IEEE C57.12.90, Reference [7], unless there would be no resulting increase to the sound levels at any point of reception within 1,000 m of the transformer substation; or
- the addition of one or more wind turbine(s) or transformer substation(s).
3.1.3 Wind facilities procured as part of the first phase of the large renewable procurement process
If an application for a renewable energy approval is submitted in respect of a wind facility for which the supply of renewable energy is procured as part of the first phase of the Independent Electricity System Operator’s Large Renewable Procurement process (LRP I), the transition rule set out below applies.
Transition Rule for Ground Factor Values: This document requires that the noise assessment for a wind facility use the ground factor values as specified in Section 6.4.10 c). For wind facilities described in the previous paragraph, the ground factor values that apply are as follows:
For Class 2 and 3 Areas, the assessment of wind turbines must use ground factor values not exceeding the following:
Gs = 1.0
Gm = 0.8
Gr = 0.5
Where: Gs is the ground factor for the source region,
Gm is the ground factor for the middle region, and
Gr is the ground factor for the receiver region.
Alternatively, a global ground factor value not exceeding 0.7 may be used.
If an application for an amendment to a renewable energy approval is submitted in respect of a change to a wind facility described in the first paragraph of this section, the approach to ground factor values noted above continues to apply to the change, provided the application does not include any of the following changes:
- a change to the location of a wind turbine or transformer substation;
- an increase to the octave-band sound power levels (linear weighted) of a wind turbine, as calculated in accordance with the standard specified in paragraph 1 of subsection 1(6.1) of Ontario Regulation 359/09, unless there would be no resulting increase to the sound levels at any point of reception within 1,500 metres (m) of the wind turbine;
- an increase to the acoustic emissions of a transformer substation, as calculated in accordance with ANSI/IEEE C57.12.90, Reference [7], unless there would be no resulting increase to the sound levels at any point of reception within 1,500 m of the transformer substation; or
- the addition of one or more wind turbine(s) or transformer substation(s).
If the application consists of one or more of the changes set out in clauses a to d above then the approach to ground factor values as specified in Section 6.4.10 c) apply in respect of those changes.
Description of wind facility noise
A typical wind turbine consists of a tall tower with a hub (nacelle or housing) containing the drive-train and generator mounted on top of the tower. The energy of the wind is converted into mechanical energy by turning three rotating blades attached to a hub and rotor. The rotor is connected to a generator which converts mechanical energy into electrical energy.
The individual wind turbines are separated by several hundred metres from each other, so that a large wind facility could cover an area of tens of square kilometres. Larger wind facilities may include a transformer substation(s) that collects and increases the voltage produced by the turbines to the higher voltage for the grid transmission system.
In general, the significant noise sources associated with the operation of a wind facility are the wind turbines and the transformer substation(s). Switching stations are not significant noise sources.
Wind turbines are considered unique noise sources as their noise emissions increase with greater wind speed at the height of the blades, up to the turbine’s rated wind speed (speed at which it generates maximum power), above which the noise level does not usually increase.
Noise from wind turbines consists of the aerodynamic noise caused by blades passing through the air and, to a lesser extent, mechanical noise created by the operation of mechanical elements such as the gearbox, generator, yaw drives, hydraulic equipment, cooling fans and parking brakes.
In general, noise from wind turbines is perceived at the point of reception as broadband in nature and composed of noise over a broad range of frequencies. The wind turbines’ overall noise levels vary greatly depending on distance, wind speed and transmission from the wind turbines to the point of reception.
Close to the wind turbines, tonal noise may also be noticed at discrete frequencies. Tonal noise is caused by components such as meshing gears, non-aerodynamic structural resonances, or unstable flows over holes or slits or a blunt trailing edge of a turbine blade. In any event, as the distance between the turbine and the point of reception increases, these effects are reduced. Tonal noise is not usually a problem in modern turbines as evidenced by examination of numerous acoustical test documents from the manufacturers.
The transformer substation noise is produced by the vibration of the transformer core and associated components, and by the operation of other equipment such as cooling fans. The noise produced by a transformer substation generally exhibits a pronounced hum, associated with the fundamental electrical frequency and its harmonics. Consequently, the transformer substation noise is typically tonal.
The noise produced by wind turbines, as well as the background noise, typically increases with wind speed. In contrast, the noise produced by a transformer substation is unaffected by wind speed.
Sound level limits for wind facilities
5.1 Sound level limits for wind facilities without transformer substation(s)
The sound level limits at a point of reception in Class 1 & 2 Areas (Urban) and Class 3 Areas (Rural) are given by the applicable values in Table 1 and Figure 1.
The sound level limits for wind turbines for wind speeds at or below 6 metres per second (m/s) are set relative to Publication NPC-300, Reference [1], but have been modified to apply in the context of wind facilities, as well as to a reference wind induced background sound level. The sound level limits, expressed in terms of the hourly, “A-weighted,” equivalent sound level (Leq), apply at the point(s) of reception.
The wind turbine sound level limits are given at integer values of the wind speed and are shown as the solid lines in Figure 1. The dashed line in Figure 1 does not represent a limit and is included only for information purposes
Wind Speed (m/s) at 10 m height | ≤ 6 | 7 | 8 | 9 | ≥ 10 |
---|---|---|---|---|---|
Wind Turbine Sound Level Limits Class 3 Area, dBA | 40.0 | 43.0 | 45.0 | 49.0 | 51.0 |
Wind Turbine Sound Level Limits Class 1 & 2 Areas, dBA | 45.0 | 45.0 | 45.0 | 49.0 | 51.0 |
If the wind facility is located in Class 3 (Rural) and only operates during daytime or it impacts sensitive areas which are only used in the daytime (such as schools, daycares, etc.), then the Class 1 & 2 (Urban) noise limits are applicable at that noise receptor.
Figure 1: Sound level limits for wind facilities
Data download of Figure 1 available in CSV format.
5.2 Sound level limits for wind facilities with transformer substation(s)
In cases where the noise impact at a point of reception is comprised of a transformer substation(s) as well as wind turbine generator(s), the applicable sound level limits are those shown in Table 1 and Figure 1, as described in Section 5.1.
The combined noise impact (i.e. from significant noise sources associated with a proposed wind facility) must comply with the sound level limits at all the wind speeds from 0 m/s to 10 m/s.
It should be noted that the acoustic emissions from a transformer substation(s) are independent and unrelated to the wind speed, unlike the acoustic emissions from wind turbine generator(s) which are wind speed dependent.
In determining the combined noise impact, a 5 dB tonal penalty adjustment must be added to the transformer substation(s) noise as per Section 6.4.8.
5.3 Sound level limits for transformer substation(s) only
In unique cases where the noise impact assessment at a point of reception is limited to the operation of the transformer substation(s), as in a case described in Section 6.4.1, the sound level limit at a point of reception is given in Publication NPC-300, Reference [1]. The limit is independent of wind induced noise.
In determining the combined noise impact, a 5 dB tonal penalty adjustment must be added to the transformer substation(s) noise as per Section 6.4.8.
Noise impact assessment report
Generally, a noise impact assessment report must be prepared by a proponent seeking an approval for a proposed wind facility. The requirements for a detailed noise impact assessment depend on the proximity of the wind facility to receptors and are described in Section 6.4. The noise impact assessment report must be submitted to the ministry in a hard copy as well as in an electronic format.
The noise impact assessment report must demonstrate compliance with the applicable sound level limits and the supporting information must be organized in a clear and concise manner. The noise impact assessment report must be prepared by a qualified acoustical consultant and the cover document must be signed by the proponent for the project.
The noise impact assessment report should be prepared early in the planning of the project and, where required, must be submitted as part of an application for an approval of a proposed wind facility, or as part of an application for an amendment to an approval. The submitted noise impact assessment report must contain complete and accurate information.
Any changes to subsequent versions of the noise impact assessment report must be explicitly documented within the noise impact assessment report.
As a minimum, the noise impact assessment report must include the following sections in the given sequence.
6.1 Project layout
The overall plan of the wind facility must be described in detail for the purpose of supporting the noise impact assessment calculations and for demonstrating compliance with the sound level limits. The general project layout description must be supported with clear maps of the site and surrounding area, complete with scale, northing, and legend information. A suitable minimum drawing scale for the overall plan of the project is required.
The following details must be included:
- Geographic location of the project study area;
- Location of wind turbine(s);
- Location of transformer substation(s) and/or switching station(s), where applicable;
- Locations of all point(s) of reception and participating receptor(s) up to 2,000 m from any wind turbine location; and
- Property boundaries of land(s) associated with the project and location of dwelling(s) therein.
The following additional information must be included, if applicable:
- Municipal zoning and land-use plan(s);
- Topographical features including roadways, terrain elevations, and ground cover; and
- Available information regarding the location and scope of other approved wind facilities and planned wind facilities, located within 5,000 m of any point of reception or participating receptor for the proposed wind facility.
6.2 Noise sources
In this document, references to noise sources will generally include land-based wind turbine generator(s) and transformer substation(s). The distance requirements for noise sources to be included within the detailed noise assessments are described in Section 6.4.2.
6.2.1 Description
The noise impact assessment report must include the description of the wind turbine generators, including: manufacturer’s make and model, maximum electrical output rating, hub height above grade, range of rotational speeds, and mode of operation.
If applicable, the noise impact assessment report must also include the description of the transformer substation(s), including all available information at the time of submission on the manufacturer’s make and model designations, maximum electrical output rating, primary and secondary voltages, method of cooling, physical dimensions, drawing showing elevation and plan views of the unit, and any noise abatement measures.
Manufacturer’s specifications should be included in an appendix to the noise impact assessment report.
6.2.2 Wind turbines
The noise impact assessment report must include the acoustic emissions of the wind turbine, as specified by the manufacturer in accordance to the CAN/CSA standard, References [3] [4], specified for the wind turbine in subsection 1(6.1) of Ontario Regulation 359/09, and for the full range of rated operation and wind speeds. As a minimum, the information must include the hub height sound power levels, octave band frequency spectrum from 31.5 Hz to 8,000 Hz, and tonal audibility at related wind speed bins. All noise assessments under CAN/CSA-C61400-11-07 standard, Reference [3] should be based on 10 m height sound power levels.
The acoustic emission information used for modelling must be determined and reported in accordance with the definition of sound power level in Ontario Regulation 359/09. For the purposes of the noise impact assessment report, the sound power level must not be rounded down to the nearest whole number.
6.2.3 Wind speed profile adjustment to wind turbine generator acoustic emissions
Subject to availability of data, the noise impact assessment report must provide the manufacturer’s acoustic emission data adjusted for the average summer night time wind speed profile of a minimum of 0.4. If the wind speed profile of a proposed site is greater than this, a higher value should be used for adjustment and calculation of the maximum sound power level. This data should be tabulated as detailed in Table 3.
6.2.4 Wind turbine generator acoustic emissions for modelling assessment
For the purpose of the noise impact assessment, the manufacturer’s sound power level at the wind turbine hub height must be used. The noise impact assessment must be based on the spectrum (octave band frequencies from 31.5 Hz to 8,000 Hz) of the proposed wind turbine having the maximum manufacturer’s sound power level and causing the greatest noise impact at a point of reception with a height of 4.5 m above ground and a distance of 1,500 m. When required under subsection 1(6.1) of Ontario Regulation 359/09, the adjustment for overall uncertainty or a fixed value must be added to the selected manufacturer’s worst case sound power spectrum, i.e. its frequency bands. The final spectrum should be referenced as the maximum sound power level spectrum.
The maximum sound power level spectrum for the proposed wind turbine(s) must be used in the noise impact assessment and tabulated in accordance with Table 3 and Table 4. For wind turbines that, pursuant to subsection 1(6.1) of Ontario Regulation 359/09, are subject to the CAN/CSA-C61400-11-07 standard, Reference [3], proponents must complete Table 3 to document the maximum sound power level spectrum, and should not complete Table 4. For wind turbines that, pursuant to subsection 1(6.1) of Ontario Regulation 359/09, are subject to CAN/CSA-IEC 61400-11:13, Reference [4], proponents must complete Table 3 for informational purposes and Table 4 for documenting the maximum sound power level spectrum.
6.2.5 Transformer substation
The noise impact assessment report must include the acoustic emissions of each transformer unit as specified by the manufacturer and must conform to the standard ANSI/IEEE C57.12.90, Reference [7]. In cases where the specific information is not available in the early stages of planning the proposed wind facility, proponents must submit a maximum rated value of the transformer(s) acoustic emissions.
For the purpose of the noise impact assessment, the top of core or cooling fans of the transformer must be used as the source height. Generally, there are large distances between the transformer substation(s) and receptors and, therefore, the transformer substation(s) must be assessed as a point noise source.
This requirement does not apply to the small transformer units attached to each wind turbine. These small transformers are insignificant noise sources and, therefore, their contributions do not require assessment.
The transformer substation(s) acoustic emissions data must be used in the noise impact assessment at each point of reception and participating receptor.
6.2.6 Noise sources and locations
All wind turbine unit(s) and transformer substation(s) must be assigned a unique source identification and must be listed along with their Universal Transverse Mercator (UTM) coordinates in a table in the noise impact assessment report. The table should be provided in electronic form along with the noise impact assessment report. A sample table format is shown in Table 5.
The source identifications should remain consistent throughout the submission and review process.
6.3 Receptor locations
To provide clarity and consistency for the detailed noise assessments, the following sections describe the specific receptor locations for the purposes of identifying points of reception and participating receptors. The distance requirements for detailed noise assessments at receptors are described in Section 6.4.1.
6.3.1 Wind facility without transformer substation(s)
In respect to the modelling scenario, the following locations must be selected
Single Storey Building or Structure Containing one or more Dwellings
footnote 3 - 4.5 m above grade at the centre of the building or structure; or
- 1.5 m above grade and 30 m horizontally from the façade of the building or structure in the direction of each wind turbine location. If the 30 m radius spans beyond the property line of the building or structure then the receptor location is at the property line.
Either of the two locations is acceptable for assessment
footnote 4 .- Two Storey Building or Structure Containing one or more Dwellings (or Raised Bungalow)
- 4.5 m above grade at the centre of the building or structure.
- Three Storey or Higher Building or Structure Containing one or more Dwellings
- at the centre of the highest storey of the building or structure.
6.3.2 Wind facility with transformer substation(s)
For receptors located within 1,000 m of a transformer substation, this section applies. For receptors located beyond 1,000 m of a transformer substation, Section 6.3.1 applies.
In respect to the modelling scenario, the following location that results in the higher noise impact must be selected.
- Single Storey Building or Structure Containing one or more Dwellings
footnote 5 - 1.5 m above grade at the centre of the building or structure; or
- 1.5 m above grade and 30 m horizontally from the façade of the building or structure in the direction of each wind turbine and transformer substation location. If the 30 m radius spans beyond the property line of the building or structure then the receptor location is at the property line.
- Two Storey Building or Structure Containing one or more Dwellings
- 4.5 m above grade at the centre of the building or structure; or
- 1.5 m above grade and 30 m horizontally from the façade of the building or structure in the direction of each wind turbine and transformer substation location. If the 30 m radius spans beyond the property line of the building or structure then the receptor location is at the property line.
- Three Storey or Higher Building or Structure Containing one or more Dwellings
- at the centre of the highest storey of the building or structure; or
- 1.5 m above grade and 30 m horizontally from the façade of the building or structure in the direction of each wind turbine and transformer substation location. If the 30 m radius spans beyond the property line of the building or structure then the receptor location is at the property line.
6.3.3 Institutional uses
The receptor must be located at the centre of the building:
- a minimum of 1.5 m above ground for a single storey building,
- a minimum of 4.5 m above ground for a two storey building,
- a minimum of 7.5 m above ground for a three storey building, or
- at the highest storey of the building if it is more than three stories.
6.3.4 Campsites and campgrounds
The receptor must be located within 30 m of sleeping areas of a portion of property that is used as a campsite or campground, at a height of 1.5 m above ground.
6.3.5 Noise sensitive zoned lot
Where a building permit or site plan approval has been issued
If the construction of a building or structure mentioned in clauses (a) or (b) of the definition of noise sensitive land use in Section 2 has not commenced but an approval under section 41 of the Planning Act or a building permit under section 8 of the Building Code Act, 1992 has been issued in respect of the building or structure, and paragraph 3 of subsection 1(4) of Ontario Regulation 359/09 applies in respect of that proposed building or structure, the receptor locations described in Sections 6.3.1 to 6.3.3 above apply.
Where a building permit or site plan approval has not been issued
The receptor location on a noise sensitive zoned lot, other than an inaccessible vacant lot, in respect of which no approval under section 41 of the Planning Act or building permit under section 8 of the Building Code Act, 1992 has been issued for a building or structure mentioned in clauses (a) or (b) of the definition of noise sensitive land use in Section 2, or where paragraph 3 of subsection 1(4) of Ontario Regulation 359/09 does not apply in respect of that proposed building or structure, must consist of the following:
- If the area of the vacant lot is smaller than 1 hectare (10,000 m²), the receptor location should be approximately in the centre of the vacant lot, at a height of 4.5 m above ground. If other factors suggest otherwise, the receptor location should be selected having regard to the existing zoning by-law(s), Minimum Distance Separation(s) Formulae or setbacks (as applicable), the typical building pattern in the area and an appropriate or likely future use of the vacant lot.
- If the area of the vacant lot is greater than 1 hectare (10,000 m²), the area of the vacant lot for noise impact assessment purposes should be considered limited to a 1 hectare (10,000 m²) square, or a rectangular shape if justification is provided. This 1 hectare portion of the vacant lot should be selected having regard to the existing zoning by-law(s), Minimum Distance Separation(s) Formulae or setbacks (as applicable), the typical building pattern in the area and an appropriate or likely future use of the vacant lot. The receptor location is the centre of this 1 hectare portion of the vacant lot, at a height of 4.5 m above ground.
6.3.6 Area classification of receptors
Based on the rural nature of the areas surrounding most wind facilities, the Class 3 Area sound level limits shown in Table 1 and Figure 1 apply to all point(s) of reception, regardless of their proximity to a roadway, unless it can be shown clearly that less restrictive sound level limits are justified.
Less restrictive sound level limits for point(s) of reception within their designated area classification must be justified by analysis of hourly traffic volumes data or by hourly acoustic monitoring results consistent with Publication NPC-206, Reference [2]. The use of general estimates, such as the Annual Average Daily Traffic data (AADT), is an insufficient method for determining the minimum hourly sound level of the background.
6.3.7 Receptors and locations
All points of reception and participating receptors must be assigned a unique receptor identification and must be tabulated along with their precise coordinates in the noise impact assessment report. The table should be provided in electronic form along with the noise impact assessment report. A sample table format is shown in Table 6 and Table 7.
The receptor identifications should remain consistent throughout the review process. Any changes to receptor identifications in revised versions of the noise impact assessment report must be explicitly stated.
6.4 Detailed noise impact assessment
Assessment of the sound levels produced by a wind facility (i.e. detailed noise impact assessment) must be made at each point of reception and participating receptor, within the distance requirements described in Section 6.4.1. In the event that all point(s) of reception and participating receptor(s) are outside the distance requirements described in Section 6.4.1, a detailed noise impact assessment is not required and the provisions contained in Sections 6.4.2 through to 6.4.10 are not applicable. Note that proposals for wind facilities must address the requirements described in Sections 6.1, 6.2 and 6.3, and Table 5, Table 6 and Table 7, even if a detailed noise assessment is not required.
The noise assessment must represent the maximum rated output of the wind facility, and reflect the principle of “predictable worst case” noise impact by including the spectrum having the maximum rated sound power level and causing the highest noise impacts at the point(s) of reception.
6.4.1 Distance requirement
- Wind Facility without Transformer Substation(s)
- A detailed noise impact assessment of the wind facility is required if one or more point(s) of reception or participating receptor(s) are located within 1,500 m of a wind turbine generator.
- Wind Facility with Transformer Substation(s)
- A detailed noise impact assessment of the wind facility including a transformer substation(s) is required if one or more point(s) of reception or participating receptor(s) are located within 1,500 m of a wind turbine generator.
- A detailed noise impact assessment limited to the transformer substation(s) is required if no point of reception or participating receptor is located within 1,500 m of a wind turbine generator but a point of reception or a participating receptor is located within 1,000 m of a transformer substation.
6.4.2 Wind facility assessment
In the event that a detailed noise impact assessment is required, the assessment must not be limited to a 1,500 m radius from a point of reception or participating receptor. It must consider the impact of the individual turbines/transformer(s) extended to distances described in Section 6.4.9 (i.e. 5,000 m).
In general, transformer substation(s) noise impact must be assessed in combination with the noise impact from the wind turbine generator(s).
6.4.3 Transformer substation assessment
In the unique case where the noise impact is caused only by the transformer substation(s), as described in Section 6.4.1 b), the detailed noise impact assessment is only required to consider the sound levels from the transformer substation(s).
6.4.4 Impact of adjacent approved and planned wind facilities
If a point of reception or a participating receptor may be affected by adjacent, approved wind facilities and/or by adjacent planned wind facilities, the detailed noise impact assessment must address, subject to available information
Note that in accordance with Section 6.4.2, where a detailed noise impact assessment is required, it must consider all the wind turbine generators and transformer substations in the proposed wind facility as well as in the adjacent approved and/or planned wind facilities, subject to the limitations relating to very large distances described in Section 6.4.9.
6.4.5 Concordance table for shared receptors
In general, the purpose of the concordance table is to facilitate the ministry’s review of a proposed wind facility that is located in close proximity to adjacent wind facilities, which have shared receptors within 2,000 m from any proposed or existing wind turbine location. Refer to Table 12 for a sample concordance table.
The concordance table cross-references the unique identification nomenclatures used by different proponents to identify shared point(s) of reception and participating receptor(s). The concordance table must be completed and submitted as part of the noise impact assessment report, where applicable.
6.4.6 Assessment of participating receptor(s) and point(s) of reception
6.4.6.1 Participating receptor(s)
The sound level limits stated in Section 5 do not apply to participating receptors. Despite this exemption, it is prudent to design wind facilities so as to minimize the noise impact on participating receptors. For further clarification on participating receptors, proponents should refer to the text in Chapter 3, section 2.2.1 of the “Technical Guide to Renewable Energy Approvals,” Reference [8].
It should also be noted that a detailed noise impact assessment will be required where a participating receptor for an adjacent approved wind facility or an adjacent planned wind facility is not considered a participating receptor for a proposed wind facility. Unless the participating receptor for the adjacent wind facility is also a participating receptor for the proposed wind facility, it shall be considered a point of reception for the purposes of the detailed noise impact assessment for the proposed wind facility.
Further, in a situation where a participating receptor for an approved or planned wind facility (Facility A) is not considered a participating receptor for an adjacent proposed wind facility (Facility B) and the noise impact at the participating receptor (Facility A) may exceed the applicable sound level limits for a point of reception, then the closest turbine of the adjacent proposed wind facility (Facility B) must exceed a distance of 1,500 m from the participating receptor (Facility A), or the combined noise impact from significant noise sources associated with the adjacent proposed wind facility (Facility B) must be less than 30 dBA at the participating receptor (Facility A).
6.4.6.2 Point(s) of reception
The sound level limits stated in Section 5 apply to points of reception as defined. In other words, the sound level limits stated in Section 5 only apply to those receptor locations on noise sensitive land uses and noise sensitive zoned lots to which the setback in subsection 54(1) of Ontario Regulation 359/09 also applies.
However, under subsection 54(1.4) of Ontario Regulation 359/09, a change to the location of a wind turbine(s) would require the proponent to publish or post notice of an updated draft site plan within 18 months of issuing the initial notice of draft site plan. Although this does not mean that the regulatory setback has to be met for the relocated wind turbine(s), the proponent must consider – for the purposes of the noise impact assessment report – all points of reception that exist on the day before the proponent published or posted notice of the updated draft site plan, but only in respect of the wind turbine(s) that is proposed to be relocated.
In this situation, what was previously not required to be considered as a point of reception is now considered a point of reception. The sound level limits stated in Section 5 will then apply to these “newly created” points of reception.
Any changes to subsequent versions of the noise impact assessment report must be explicitly stated within the report.
A sample scenario is provided below to assist with understanding the situation described in Section 6.4.6.2:
A proponent proposes a wind facility comprised of two wind turbines (T1 and T2) located 4,000 m apart. T1 has two points of reception (R1a and R1b), and T2 has three points of reception (R2a, R2b and R2c), associated with their locations. All five points of reception are located more than 550 m from a wind turbine and have noise impacts of 40 dBA or less (@ 6 m/s).
On March 1, 2016, the proponent publishes or posts notice of its draft site plan, effectively fixing the five points of reception that it must assess. On April 1, 2016, resident X and resident Y each obtain a building permit to construct homes (Rex and Rey) 400 m away from T1 and T2, respectively.
On April 1, 2016, the new receptor locations, Rex and Rey, are not considered points of reception, as the notice of draft site plan was published or posted before the building permits were issued. As a result, the wind facility is not required to meet the regulated setback distance at Rex or Rey, nor is the wind facility required to meet the 40 dBA sound level limit (@ 6 m/s) at those locations.
On May 1, 2016, the proponent publishes or posts notice of an updated draft site plan which shows that T1 will move by 25 m. Consequently, Rex is now a point of reception and the 40 dBA sound level limit (@ 6 m/s) applies at that location. However, the regulated setback distance does not apply provided the proponent submits an application for an approval to the ministry within 18 months of issuing the initial notice of draft site plan (i.e. by August 30, 2017), and all of the other draft site plan requirements are met.
Rey continues to not be considered a point of reception as none of the wind facility’s significant noise sources, in close proximity to Rey, have moved. (Close proximity means 1,500 m for wind turbines and 1,000 m for transformer substations).
6.4.7 Prediction method
Predictions of the total sound level at a point of reception or a participating receptor is based on the method described in the standard ISO 9613, References [5] [6]. The calculations are subject to the specific parameters indicated in Section 6.4.10.
6.4.8 Adjustment for special quality of sound
Wind facility noise perceived at receptors is typically broadband aerodynamic noise in nature. However, the broadband aerodynamic noise could also include audible tones. Noise that is tonal in character has a relatively high level of acoustic energy over a narrow frequency range that is not masked by noise in adjacent frequencies. Therefore, it is important to have a precise and objective tonality analysis method to assess the tones and to carefully consider audible tones present within noise emissions from all significant noise sources (including wind turbines and transformer substation(s)) within the wind facility.
Wind Turbines:
As noted in Section 6.2.2, the acoustic emission information for a wind turbine must be determined and reported in accordance with the definition of sound power level.
If there is a concern with the tonal characteristic of sound from a proposed wind turbine model(s) or if the turbine(s) manufacturer’s specification shows tonal audibility to be a positive value, the requirements defined in the following paragraphs apply:
- If the manufacturer’s tonal audibility data for wind turbine(s) are equal to or below 3 dB, tonal adjustments to the turbine’s acoustic emissions is not required. If the manufacturer’s tonal audibility data for wind turbine(s) are greater than 3 dB but less than 4 dB, a detailed acoustic emission report is required for each proposed wind turbine model, in order to show the frequencies at which tones occur.
- If the manufacturer’s tonal audibility data for the wind turbine(s) are 4 dB or greater, then a 5 dB tonal penalty adjustment must be added to the wind turbine’s acoustic emissions. This fixed 5 dB tonal penalty should be applied to the overall acoustic emissions at each wind speed at which the tone was detected.
Transformer Substation
The calculation of transformer substation noise must be consistent with Section 6.2.5.
The transformer substation noise is produced by the vibration of the transformer core and associated components, and by the operation of other equipment such as cooling fans. The noise produced by a transformer substation generally exhibits a pronounced hum, associated with the fundamental electrical frequency and its harmonics. Consequently, the transformer substation(s) acoustic emission is typically tonal.
Therefore, in determining the noise impact at the point(s) of reception, a 5 dB tonal penalty adjustment must be added to the transformer substation acoustic emissions.
6.4.9 Sound level contributions from distant wind facilities
The standard on which the noise impact prediction method is based is ISO 9613, References [5] [6]. Contributions from noise sources located at distances larger than 5,000 m from point(s) of reception and/or participating receptor(s), do not need to be considered.
6.4.10 Specific parameters
The noise impact assessment must use the following parameters that have been designed to provide clarity and consistency as well as reflect the principle of the “predictable worst case” noise impact.
- All calculations must be performed in terms of sound level spectra within octave band frequencies ranging from 31.5 Hz to 8,000 Hz and the hub height wind speed, as a minimum, from 0.8 to 1.3 times the wind speed at 85% of maximum power rounded to the centres. Indicatively, this is a wind speed range of approximately 6 to 10 m/s at 10 m height, depending on the turbine type.
The attenuation due to atmospheric absorption must be based on the atmospheric attenuation coefficients for a temperature of 10ºC and a relative humidity of 70%. These are summarized and outlined in Table 2 below:
Table 2: Atmospheric absorption coefficients associated with various octave band frequencies Octave Band Frequency (Hz) 31.5 63 125 250 500 1,000 2,000 4,000 8,000 Atmospheric Absorption Coefficient (dB/km) 0.0 0.1 0.4 1.0 1.9 3.7 9.7 32.8 117.0 The term for ground attenuation is calculated using the “general” method in the standard ISO 9613-2, Reference [6]. For Class 2 and 3 Areas, the assessment of wind turbines must use a global ground factor value or individual ground factor values (Gs, Gm, Gr) not exceeding 0.5.
Ground factor values for assessments in Class 1 Areas and areas around transformer substation(s) are not specified in this document. The choice of the ground factor values for noise impact assessments in those areas are site-specific. Typically, the area around the transformer substation is expected to be hard ground as defined in ISO 9613-2, Reference [6].
Concave Ground Profile
With respect to intermediate calculation between individual point(s) of reception and/or participating receptor(s) and wind turbine, a further correction of +3 dB should be added to the calculated partial A-weighted noise level for propagation “across a valley,” or where the ground falls away significantly, between the individual turbine and the receptor location. The criterion of application is provided in Equation 1:
Equation 1
hm ≥ 1.5 x ((hs - hr) / 2)
where hm is the mean height above the ground of the direct line of sight from the receiver to the source (as defined in Figure 3 of ISO 9613-2, Reference [6]), and hs and hr are the heights above local ground level of the source and receptor respectively. This may be calculated using standard topographic data with a resolution of 50 m or less. Care needs to be exercised when evaluating this condition, as small changes in distance and height may trigger (or not) the criterion when the actual situation has not changed significantly. Examination of ground profiles between sources and point(s) of reception and/or participating receptor(s) can assist in determining its application.
6.5 Results and compliance
6.5.1 Presentation of results
Results of the predictable worst case noise impact assessment calculations must be presented in accordance with the Noise Impact Assessment Summary Tables, (Table 8, Table 9, Table 10 and Table 11). In addition, the results (based on the maximum sound power level of the turbine(s)) should be plotted on drawings of the site plan, showing property boundaries, noise sources and point(s) of reception and participating receptor(s) locations with their identifications. A suitable scale for these drawings should be provided in the drawing(s).
6.5.2 Assessment of compliance
Compliance must be based on the comparison, at each point of reception, of the combined noise impact as determined under Section 6, with the sound level limits stated in Section 5. All calculations and the determination of compliance with the sound level limits must be presented to a precision of one decimal place.
6.6 Summary tables
6.6.1 Wind turbine acoustic emissions summary table
The wind turbine acoustic emissions data used in the calculations must be presented as shown in the following tables. Separate tables should be used if the project involves different models of equipment.
See Tables 3 and 4 in the Noise Guidelines for Wind Farms – Summary Tables document.
6.6.2 Locations of wind turbine generators, transformer substation(s), point(s) of reception and participating receptor(s)
Location coordinates of all wind turbine generators, transformer substations, points of reception and participating receptors must be given in accordance with Table 5, Table 6 and Table 7.
See Tables 5 - 7 in the Noise Guidelines for Wind Farms – Summary Tables document.
6.6.3 Noise impact assessment summary tables
See Tables 8 - 12 in the Noise Guidelines for Wind Farms – Summary Tables document.
6.7 Appendices
All information necessary to support the conclusions of the noise impact assessment report, but not specifically described as required in Section 6, should be referenced and attached as Appendices to the noise impact assessment report. Supporting information includes but is not limited to specifications, drawings, letters/agreements, photos, measurements and miscellaneous technical information.
In addition, a sample calculation should be included in the Appendices. The sample calculation must include at least one detailed calculation for a source to a point of reception or participating receptor “pair,” preferably addressing the receptor with the highest calculated combined noise impact and the closest wind turbine unit. The sample calculation must represent all other “pairs.” If applicable, a sample calculation for the transformer substation is also required.
In cases where a transformer substation(s) is part of the wind facility, inclusion of Table 13 and Table 14 in the Appendices should be considered:
See Tables 13 and 14 in the Noise Guidelines for Wind Farms – Summary Tables document.
Footnotes
- footnote[1] Back to paragraph The measurement of wind induced background sound level is not required to establish the applicable limit. The wind induced background sound level reference curve, represented by the dashed line in Figure 1, was determined by correlating the A weighted ninetieth percentile sound level (L90) with the average wind speed measured at a particularly quiet site. The applicable Leq sound level limits at higher wind speeds are given by adding 7 dB to the wind induced background L90 sound level reference values.
- footnote[2] Back to paragraph Assessment at the centre of the building or structure containing the dwelling(s) is simpler. The sound level at the highest storey at the centre of the building or structure containing the dwelling(s) is generally higher except where transformer substation noise is a factor.
- footnote[3] Back to paragraph With respect to the definition of dwelling, a seasonal residence, while not being occupied on a year-round basis, is occupied regularly on a seasonal basis. The seasonal residence must have features that support its use as a dwelling, for example, some sort of servicing (e.g. electrical power, domestic water supply, septic system, gas supply) to support cooking, eating, living, sleeping and sanitary facilities. Summer homes or cottages are examples of a seasonal residence, while a holiday trailer or camper pulled onto a site on a temporary basis would not be considered a dwelling. The site may, however, be considered a campsite or campground if that definition is satisfied.
- footnote[4] Back to paragraph Assessment at the centre of the building or structure containing the dwelling(s) is simpler. The sound level at 4.5 m above grade at the centre of the building or structure containing the dwelling(s) is generally higher.
- footnote[5] Back to paragraph With respect to the definition of dwelling, see footnote 3 regarding seasonal residences.
- footnote[6] Back to paragraph The combined noise impact would be expected to be assessed if, for example, the information on turbine locations and models at an adjacent wind facility is publicly available (e.g. through a notice of draft site plan and noise impact assessment report).