Appendix I Shadow Flicker Report

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1 Appendix I Shadow Flicker Report

2 Report Wind Turbine Shadow Flicker Analysis Update For McLean s Mountain Wind Farm Prepared for: Attention: Dillon Consulting Ltd. 235 Yorkland Blvd., Suite 800 Toronto, Ontario M2J 4Y8 Mr. Don McKinnon Tel: (416) , Ext Fax: (416) dpmckinnon@dillon.ca Prepared by: Alex Tsopelas, B.Eng., Ext. 356 Wind Resource Analyst atsopelas@ortech.ca and David Warner, Ext. 462 GIS Specialist dwarner@ortech.ca Tel: (905) Fax: (905) Project No.: SF 22 pages Date: July 21, Southdown Road, Mississauga, ON Canada L5J 2Y4 Tel Fax

3 Wind Turbine Shadow Flicker Analysis Update EXECUTIVE SUMMARY Dillon Consulting Ltd. (Dillon) contracted ORTECH Power (ORTECH) to complete an update to the shadow flicker analysis for the proposed McLean s Mt wind farm that was originally prepared July 6. New turbine and house (receptor) coordinates were provided by Dillon. To ensure a worst case scenario, the houses were assumed to have a 1.22m x 1.22m (1.5m 2 ) window on each of the four sides of the house with a center height 2m above ground level. The windows were oriented at 90 intervals; 0, 90, 180 and 270 from north, angles which were chosen to be approximately at right angles to the roads. The turbines were assumed to be rotating 100% of the time which is a significant overestimation when considering common capacity factors. The analysis also assumed the rotor plane was always directly facing the sun, maximizing the shadowed area when in fact, a considerable amount of time the turbine will be facing some direction other than directly at the sun which would greatly reduce the shadow size. The resulting annual shadow flicker hours on each house were then reduced by the amount of time (hours) in which there was % cloud cover, based on historic Environment Canada meteorological data from Sudbury. The maximum and average shadow flicker time on a daily basis was not adjusted. The analysis indicates there are no houses which receive greater than 30 hours of shadow flicker per year when accounting for cloud cover, while seven homes experience a maximum daily shadow flicker greater than 30 minutes. These results are highlighted in red with yellow type. As this simulation is based on a worst case scenario, it is unlikely that many of the houses will noticeably experience the number of hours of shadow flicker that is reported here. i

4 Revised Wind Turbine Shadow Flicker Analysis Update TABLE OF CONTENTS EXECUTIVE SUMMARY... 3 INTRODUCTION... 1 METHODOLOGY... 2 RESULTS... 4 MITIGATION OPTIONS... 7 ANALYSIS RESULTS TABLES... 8 APPENDIX 1 Turbine Locations APPENDIX 2 Receptor Locations LIST OF FIGURES Figure 1: Map of Project Area With Residences Exceeding 30min Per Day Threshold Highlighted... 6 LIST OF TABLES Table 1: Summary of Residences With Potential for More Than 30min Daily or 30h Annually... 5 Table 2: Cloud Cover Data for Windsor Airport... 8 Table 3: Analysis Results... 9

5 Wind Turbine Shadow Flicker Analysis Update Page 1 of 22 INTRODUCTION Dillon Consulting Ltd. (Dillon) contracted ORTECH Power (ORTECH) to complete an update to the shadow flicker analysis for the proposed McLean s Mt wind farm submitted July under ORTECH project # The McLean s Mt wind farm is located on the northeast part of Manitoulin Island near Little Current, Ontario. Shadow Flicker Phenomena Shadow flicker is caused when rotating turbine blades disrupt the sun s rays as they are cast on incident surfaces, such as a window of a nearby house. When the incident surfaces affected are windows at nearby houses, shadow flicker becomes a problem that must be minimized through effective planning and design incorporating the impacts of shadow flicker. Impacts of Shadow Flicker Wind turbines located near residences can cast a flickering shadow on the windows that is generally described as annoying. There are rare cases in which flickering light above 3 HZ can trigger epileptic seizures in those prone to the condition 1. The rotor speeds of the proposed Vestas V90 1.8MW turbine are variable, changing with the strength of the wind, but will always range from 9 to 14.5 revolutions per minute (RPM). If sunlight were to pass directly between one of these three-bladed wind turbines, rotating near its maximum speed, the maximum respective flicker frequency would be approximately 60 RPM, or 1 Hz (3 blades x 20 RPM each). Although the Vestas V90 1.8MW turbine rotates too slowly to trigger serious epileptic seizures or other health effects, it is considered a visual annoyance if experienced on a regular basis. Established Guidelines There are no established regulations defining acceptable levels of shadow flicker at residences located near wind turbines in Canada or North America. However, a commonly-adopted industry guideline is to allow no more than 30 hours of flicker per year at any individual receptor. Internet sources often quote that this standard was implemented by a judge in a German court case, but specific details are vague 2. A 1999 German report on the visual aspects of wind turbines in the state of Schleswig-Holstein, which were subsequently adopted by most federal states in Germany for their licensing procedures, recommended that the maximum permissible time that a shadow can be cast at an imission point was 30 hours annually or 30 minutes per day, Shedding Light on Epilepsy, by G. Erba, MD a consensus of international epilepsy experts agreed that flickering light between 5 and 30 HZ can trigger seizures and as a caution, suggest that those prone to epilepsy should not be exposed to flashes over 3 HZ. 2 As quoted in Danish Wind Industry Ass. Guided tour, online at:

6 Wind Turbine Shadow Flicker Analysis Update Page 2 of 22 respectively, based on the astronomical possible maximum period 3. These limits however, were only to apply in times when the residence was occupied. The 30 hr limit is also consistent with Enbridge Wind Farm OMB Decision hearing report, where Bruce County recommended that no more than 30 hours per year be accepted when the modeling of shadow flicker is being undertaken. METHODOLOGY Elevation data for the wind farm site was downloaded from as a.dem file, converted to the appropriate WindFarm format and loaded into a new WindFarm project. A layout was created by importing the turbine and residence coordinates as provided by Dillon. A coordinate within the wind farm site was input to the project data in WindFarm for calculation of the solar zenith angle throughout the year at this location. The turbine geometry used in the analysis was for a Vestas V90 1.8MW as obtained from the technical specification document provided. The following sources were used as model inputs in this project. 1. The geographic locations, hub height and rotor diameter of the proposed wind turbines. o Acquired Vestas V90 1.8MW turbines with an 80 m hub height and 90 m rotor diameter were used. Locations are provided in APPENDIX The geographic locations of the receptors which are located within 1000 m of any turbine. o Found in APPENDIX 2 of this report. 3. A digital elevation model of the surrounding topography. o Modelled from Canadian Digital elevation data (CDED), gridded at 50 m intervals. 4. The size of the windows at each receptor, its orientation and tilt. o Generic window sizes of 1.22 x 1.22 m (WxH) were used at a center height of 2 m above the ground and a tilt angle of 0 degrees. 5. The geographic latitude and longitude of the project, for celestial calculations. o The general site location used as celestial input was in the central region of the proposed wind farm. 6. Time zone, for celestial calculations. o Time zone used was GMT -5 hours. 7. Percentage of bright sun cover, for adjusting output results to account for actual climate of area. o 54% of time with % cloud cover which was determined from Sudbury weather data. 3 As referenced in Hau, E Wind Turbines: Fundamentals, Technologies, Application, Economics. Springer. 786 pp.

7 Wind Turbine Shadow Flicker Analysis Update Page 3 of 22 The WindFarm software performs the analysis by computing the number of hours that a turbine rotor disc (blades), viewed from the window of a house is in line with the sun and, therefore, the potential for shadow flicker exists. This is done iteratively by calculating the time each turbine rotor disc is shadowing each window in each house. Without specific information on the geometry and orientation of each window in each of the 282 houses modeled, and to emulate worst case conditions, the analysis was based on a standard house with each side containing one large (1.22m x 1.22m) window and every residence consisting of 4 windows, one facing north, east, south and west, with the center of all windows 1.5m above ground level. This house model is consistent with other shadow flicker analyses that have been reviewed in Ontario. The window size, direction and height were entered manually by combining data from the layout file from the previous analysis with the new residence and turbine coordinates in a text editor. The software performs the computations without regard for the intensity of the shadow and gives a binary result of shadow or no shadow. The maximum distance of the shadow s effect was set to 1000m as is recommended in the software documentation; any turbine more than 1000m away will not register as causing shadow flicker on a residence. This value was used based on previous experience showing negligible differences in results using 1000m and 2000m. To ensure a worst case scenario simulation the following are built into the model: The turbine is always producing power with the blades constantly rotating; The turbine rotor disk is always oriented to maximize the shadowed area for each receptor No obstructions exist in the landscape (trees, fenclines, buildings) to block the sightline from receptor to turbine Each house has a large window on each side so potential for flicker exists in every direction However, in actuality, the above assumptions are not realistic and so overestimate the flicker effects for the following reasons: The turbine blades will not be rotating when the wind is calm and very strong (<3m/s and >25m/s). Also, during maintenance, the turbine cannot be operated. The turbine will rarely be directly facing the sun which will reduce the size of the shadowed area. The sight line between receptors and turbines may be blocked by existing obstructions (trees, other buildings etc.). Atmospheric diffusion reduces the intensity of the shadow over distance which is accepted to be unnoticible at a distance of 1000m. For this reason a 1000m limit was imposed in the simulation. If these likely realities were incorporated in the modeling, studies have estimated that the potential for shadow flicker would be 82% lower than those using the worst-case scenario approach

8 Wind Turbine Shadow Flicker Analysis Update Page 4 of 22 Since shadow flicker only occurs when there is direct sunlight, cloud cover data was collected from Environment Canada for the Sudbury meteorological station as shown in Table 2. The cloud cover amounts are consistent with other areas in central and southern Ontario. The fraction of time with % cloud cover was calculated and multiplied by the shadow flicker analysis results to give a more accurate representation of the actual time of shadow flicker occurrence. Some of the time when cloud cover is sparser (i.e. <80%), the shadow will be not be evident, however, this was not accounted for to ensure a worst case result. Not included in this analysis is the existence of trees, other vegetation and other buildings; discounting of these terrain features has produced a more conservative result. RESULTS Table 3 provides the analysis results showing the residence ID as provided, window information; number, direction, and the shadow information for the window. The results include the average and maximum number of hours of daily shadow flicker for each window. Also shown is the total number of hours annually of flicker, before and after cloud cover correction. Daily maximums higher than 30 minutes and annual values greater than 30 hours are highlighted in red. Table 1 gives a summary of the residences that exceed daily and annual limits for shadow flicker events. There were no residences that experienced more than 30 hours of flicker in a year after considering cloud cover. Window numbers represent the four orientations; 1 for 0, 2 for 90, 3 for 180 and 4 for 270. Figure 1 is a map of the project area and shows the houses that may experience more than 30 minutes of consecutive shadow flicker in one day.

9 Wind Turbine Shadow Flicker Analysis Update Page 5 of 22 Table 1: Summary of Residences With Potential for More Than 30min Daily or 30h Annually Receptors With Daily Max >30min (0.50h) Receptors With Annual >30 Hours No Cloud Cover Receptors With Annual > 30 Hours Cloud Cover ID - Windows ID - Windows ID - Windows 57-2/ / / / / / / /3

INSET A 194 193 192 Tamarack Lane Bay St 52 53 25 26 27 29 31 32 3028 54 59 49 51 5047 48 46 20 45 19 21 22 24 23 15 186 188 187 156 155 154 153 152 63 61 60 65 62 64 56 55 18 17 16 14 189 190 191 37

74 78 76 73 75 69 72 67 71 70 68 3 66 57 25 33 35 58 195 182 166 165 164 157 170 171 158 163 169 172 162 161 168 173 159 160 167 174 183 38 197 199 196 198 41 228 213 212 226 214 211 225 210 215 224

Sideroad 20 142 145 144 143 Lake Rd Green Bush Rd 17 Perch Lake Rd Hall St 241 240 239 8 7 18 23 29 34 Townline Rd North Channel Dr Willis Rd 21 20 281 30 16 2 Morphets Side Rd 11 10 12 10 146 185

Burnets Side Rd 15 274 272 Bass Lake 267 264 268 269 4 279 278 280 277 276 271 9 139 137 138 Little Current 136 135 134 140 141 133 Orrs Rd 6 Mill St Mcleans Mountain Windfarm Figure 1 Map of Project

10 INSET A Tamarack Lane Bay St North Channel 540 Sideroad Lake Rd Green Bush Rd 17 Perch Lake Rd Hall St Townline Rd North Channel Dr Willis Rd Morphets Side Rd Perch Lake INSET A Burnets Side Rd Bass Lake Little Current Orrs Rd 6 Mill St Mcleans Mountain Windfarm Figure 1 Map of Project Area with Residences Exceeding 30mins Per Day Threshold Highlighted Legend Inset Map North Channel Lake Huron Turbine Residence Residences Exceeding 30mins Per Day Threshold Secondary Roads Highway Rivers Access Roads Transmission Line (115kv) Project Area Lots Waterbody Wetland Woodlots Study Area Manitoulin Island Georgian Bay Darius Sideroad Indian Mountain Rd Rockville Rd Bidwell Rd een Bay Rd Pike Lake 0 1,000 2,000 3,000 Created By: KWR Checked By: JP Date Created: June 08, 2009 Date Modified: July 22, 2009 File Path: I:\GIS\Northland Power\ Mapping\Figure 1 Map of Project Area with Residences Exceeding 30min Per Day Threshold Highlighted.mxd

11 Wind Turbine Shadow Flicker Analysis Update Page 7 of 22 MITIGATION OPTIONS This analysis is conservative and it is unlikely that all of the residences listed in this report will experience shadow flicker problems however, some residences may experience more than 30 consecutive minutes in a day which would require efforts to reduce the effect. It is suggested to monitor any actual effects at the affected houses and if any shadow flicker problems are evident, tree plantings and/or brief shut-down of specific turbines during shadow flicker times may be required. A text file which shows the start time, stop time and duration of each event on each window will be included with this report as on CD for use if modification of turbine operation times is found to be necessary.

12 Revised Wind Turbine Shadow Flicker Analysis Update Page 8 of 22 ANALYSIS RESULTS TABLES Table 2: Cloud Cover Data for Sudbury Coverage Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Total % of Time 0-2 Tenths % 3-7 Tenths % 8-10 Tenths %

13 Revised Wind Turbine Shadow Flicker Analysis Update Page 9 of 22 Project : NPI-MCLEANS Run Name : H:\ ORTECH POWER\ DILLON MANITOULIN PM + SF\WINDFARM\NPI-MCLEANS\MCLEANS SHADOW UPDATE JULY 20.WFK Title : McLeans Shadow Update July 20 Time : 7/21/ :22 SUMMARY OF SHADOW TIMES ON EACH WINDOW Table 3: Analysis Results SUMMARY OF SHADOW TIMES ON EACH WINDOW House/ Easting Northing Width Depth Height Degrees Tilt Days Max Mean Total Total Window from angle per hours hours hours Hours North year per per Less Cloud (m) (m) (m) day day Cover 1/ / / / / / / / / / / / / / / / / / / / / / / / / / / / / / / / / / / / / / / / / / / / / / / / / / / / / / / / / / / / / / / / /

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13 SHADOW FLICKER Introduction Methodology

13 SHADOW FLICKER Introduction Methodology Table of contents 13 SHADOW FLICKER... 13-1 13.1 Introduction... 13-1 13.2 Methodology... 13-1 13.2.1 Factors Influencing Shadow Flicker Occurrence... 13-2 13.2.2 Shadow Flicker Analysis Methodology...