PLANNING. Planning for Renewable Energy A Companion Guide to PPS22

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1 Planning shapes the places where people live and work and the country we live in. It plays a key role in supporting the Government s wider economic, social and environmental objectives and for sustainable communities. PLANNING Planning for Renewable Energy A Companion Guide to PPS22

2 Planning for Renewable Energy A Companion Guide to PPS22

3 Acknowledgements This guide has been produced by Ove Arup and Partners. The project was supervised by officials from ODPM and DTI and supported by an advisory group, comprising representatives of: British Wind Energy Association Renewable Power Association British Biogen Royal Town Planning Institute Scottish Natural Heritage/The Landscape Institute Royal Society for the Protection of Birds Government Office for the South West Government Office for the North West London Borough of Merton DTI Defra The project team comprised representatives of Arup, TNEI Services Ltd and Dulas Ltd. The Department and its consultants wish to thank all those who assisted with the guide, including those who kindly gave their permission for the use of case studies and other material. Queen s Printer and Controller of Her Majesty s Stationery Office 2004 Copyright in the typographical arrangement and design and rests with the Crown Published for the Office of the Deputy Prime Minister, under licence from the Controller of Her Majesty s Stationery Office. This publication excluding logos, may be reproduced free of charge in any format or medium for research, private study or for internal circulation within an organisation. This is subject to it being reproduced accurately and not in a misleading context. The material must be acknowledged as Crown copyright and the title of the publication specified. For any other use of this material please write to The HMSO Licensing Division, HMSO, St Clements House, 2-16 Colegate, Norwich NR3 1BQ. Fax or licencing@cabinet-office.x.gsi.gov.uk ISBN Product code 04PD02691

4 176 PLANNING FOR RENEWABLE ENERGY Technical Annex : Wind operators in the UK and acts as a central point of contact for identifying specific consultees relevant to a site. OFCOM will identify any radio installations relevant to a wind farm site. Although OFCOM passes any enquiry on to other interested parties, who should respond to an application, this process is only partial and an applicant seeking planning permission would be well advised to make direct contact with any authorities/bodies which are likely to be interested a list of potentially interested parties is given at the end of this Section. 72. In addition, it may be necessary to consult the local water company, gas company and electricity company, and also emergency services such as the police, ambulance service and the coastguard. Shadow Flicker and Reflected Light 73. Under certain combinations of geographical position and time of day, the sun may pass behind the rotors of a wind turbine and cast a shadow over neighbouring properties. When the blades rotate, the shadow flicks on and off; the effect is known as shadow flicker. It only occurs inside buildings where the flicker appears through a narrow window opening. The seasonal duration of this effect can be calculated from the geometry of the machine and the latitude of the site. Although problems caused by shadow flicker are rare, for sites where existing development may be subject to this problem, applicants for planning permission for wind turbine installations should provide an analysis to quantify the effect. A single window in a single building is likely to be affected for a few minutes at certain times of the day during short periods of the year. The likelihood of this occurring and the duration of such an effect depends upon: the direction of the residence relative to the turbine(s); the distance from the turbine(s); the turbine hub-height and rotor diameter; the time of year; the proportion of day-light hours in which the turbines operate; the frequency of bright sunshine and cloudless skies (particularly at low elevations above the horizon); and, the prevailing wind direction.

5 PLANNING FOR RENEWABLE ENERGY Technical Annex : Wind 177 Only properties within 130 degrees either side of north, relative to the turbines can be affected at these latitudes in the UK turbines do not cast long shadows on their southern side. 74. The further the observer is from the turbine the less pronounced the effect will be. There are several reasons for this: there are fewer times when the sun is low enough to cast a long shadow; when the sun is low it is more likely to be obscured by either cloud on the horizon or intervening buildings and vegetation; and, the centre of the rotor s shadow passes more quickly over the land reducing the duration of the effect. 75. At distance, the blades do not cover the sun but only partly mask it, substantially weakening the shadow. This effect occurs first with the shadow from the blade tip, the tips being thinner in section than the rest of the blade. The shadows from the tips extend the furthest and so only a very weak effect is observed at distance from the turbines. 76. Shadow flicker can be mitigated by siting wind turbines at sufficient distance from residences likely to be affected. Flicker effects have been proven to occur only within ten rotor diameters of a turbine. Therefore if the turbine has 80m diameter blades, the potential shadow flicker effect could be felt up to 800m from a turbine. 77. Around 0.5 % of the population is epileptic and of these around 5 % are photo-sensitive. Of photo-sensitive epileptics less than 5 % are sensitive to lowest frequencies of Hz, the remainder are sensitive only to higher frequencies. The flicker caused by wind turbines is equal to the blade passing frequency. A fast-moving three-bladed machine will give rise to the highest levels of flicker frequency. These levels are well below 2 Hz. The new generation of wind turbines is known to operate at levels below 1 Hz. 78. Turbines can also cause flashes of reflected light, which can be visible for some distance. It is possible to ameliorate the flashing but it is not possible to eliminate it. Careful choice of blade colour and surface finish can help reduce the effect. Light grey semi-matt finishes are often used for this. Other colours and patterns can also be used to reduce the effect further. (See The Influence of Colour on the Aesthetics of Wind Turbine Generators ETSU W/14/00533/00/00).

14 INFRASTRUCTURE, TELECOMMUNICATIONS & SHADOW FLICKER

Knockskae Wind Farm Environmental Statement Volume 2 Main Report 14-1 14 INFRASTRUCTURE, TELECOMMUNICATIONS & SHADOW FLICKER 14.1 Introduction 14.1.1 This Chapter has been prepared by. It identifies and