External Lighting Assessment - · PDF filedeveloper’s designers when undertaking the full external lighting design of the site. ... External Lighting Assessment August 2011 . Anaerobic

Prepared for AeroThermal Group

Anaerobic Digestion Facility

External Lighting Assessment

August 2011


Scott Wilson 3

rd Floor

Mayflower House Armada Way Plymouth PL1 1LD Tel 01752 676700 Fax 0870 238 6023 www.scottwilson.com

This document has been prepared in accordance with the scope of Scott Wilson's appointment with its client and is subject to the terms of that appointment. It is addressed to and for the sole and confidential use and reliance of Scott Wilson's client. Scott Wilson accepts no liability for any use of this document other than by its client and only for the purposes for which it was prepared and provided. No person other than the client may copy (in whole or in part) use or rely on the contents of this document, without the prior written permission of the Company Secretary of Scott Wilson Ltd. Any advice, opinions, or recommendations within this document should be read and relied upon only in the context of the document as a whole. The contents of this document do not provide legal or tax advice or opinion. © Scott Wilson Ltd 2010

Revision Schedule External Lighting Assessment August 2011

Rev Date Details Prepared by Reviewed by Approved by

00 10.08.11 Draft – Issued to client for comment

Bonnie Brooks Assistant Electrical Engineer

Mike Ainger Senior Electrical Engineer

Neil Cumming Technical Director

01 01.09.11 Final – revised in accordance with client comments

Bonnie Brooks Assistant Electrical Engineer

Mike Ainger Senior Electrical Engineer

Neil Cumming Technical Director


Environmental Statement External Lighting Assessment August 2011

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Table of Contents

1 Executive Summary ........................................................................ 3

2 Introduction ..................................................................................... 4

2.1 General........................................................................................................................... 4

2.2 Scope of External Lighting Report .................................................................................. 4

2.3 Objectives....................................................................................................................... 4

3 Relevant Standards & Guidance .................................................... 6

4 Standards & Guidance Overview ................................................... 7

5 Assessment Methodology ............................................................ 10

6 Baseline Conditions...................................................................... 11

7 The Proposed Lighting Scheme – Design Approach.................. 14

7.1 Recommended Lighting Values .................................................................................... 14

7.2 Strategy for Minimising Obtrusive Light, Mitigating the Effect on Bats and Reducing the Visual Impact of the Lighting Scheme ..................................................... 15

7.3 Strategy for Luminaire Types........................................................................................ 16

7.4 Part-Lighting Strategy and Luminaire Controls.............................................................. 16

8 Assessment of the Impact of the Lighting Scheme.................... 17

9 Conclusions................................................................................... 18

Appendix 1: Lighting Terminology Appendix 2: Extract from SLL Code for Lighting – Obtrusive – Recommended Lighting Values

Appendix 3: Extract from SLL code for Lighting – General Areas in Outdoor Work Places – Recommended Lighting Values

Appendix 4: Luminaire Details

Appendix 5a: Relux Calculation Result- ‘Worst Case Scenario’: All lights switched on

Appendix 5b: Relux Calculation Result- Sky Glow Appendix 6: Scope of Lease drawing



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Drawing E01 & E02: Levels of Illuminance –

7am till dawn & dusk till 7pm

Drawing E03 & E04: Levels of Illuminance – Part-lighting 7pm till 7am

Drawing E05: Sky Glow Calculation



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1 Executive Summary

This document has been prepared to outline the fixed external lighting scheme proposed for the Anaerobic Digestion Facility. An appropriate lighting scheme for the site has been assessed in order to establish its effects on the surrounding environment and neighbouring properties. The lighting scheme in this report is to be viewed as a lighting design strategy rather than a detailed design solution. It is recommended that the lighting strategy outlined in this report is adopted including criteria, luminaire types, switching methods, lamp types etc. by the developer’s designers when undertaking the full external lighting design of the site. The proposed lighting scheme will comply with all relevant British Standards, the Institute of Light and Lighting Guidelines and guidance provided by the Society of Light and Lighting. These documents and other relevant standards are scheduled and summarised within the report.

The scheme proposed controls the lighting level such that the illuminance levels are below 1 Lux at a distance of 30m from the nearest residential property. Lighting as proposed will not cause excessive glare to neighbouring residential properties from this site. The majority of the fittings will not be visible to neighbouring domestic properties. Consideration has been given to mitigating the impact on the bats in the area, and in particular their flight paths through the site. Upward light pollution (Sky-glow) is limited by specifying luminaires which have a zero upward light component. Drawing E05 shows that the effect on the night sky will be negligible inside the site and zero outside the site. External lighting illumination levels will be based on CIBSE guidance and in accordance with the Clients requirements to maximise safety for all operatives working on the site and visitors, whilst maintaining a minimal impact on the site surroundings, environment and neighbouring properties. The illumination levels for various areas and times are detailed later in this report. This scheme also takes into consideration the need to reduce energy consumption, whilst maintaining a high quality of illumination for the site. This is achieved by using low energy lamp types, the minimum number of lighting columns/ points, energy efficient controls and part-lighting strategy.



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2 Introduction

2.1 General

This report only covers the fixed external lighting installation within the boundary of the Clients lease agreement and in the additional shared vehicular access route on the north western side of the site. See Appendix 6 - Scope of Lease drawing. All existing external lighting within the leased area will be permanently disconnected. Traffic routes and associated calculation measuring plane positions for the purpose of this assessment have been estimated. Final luminaire positions to be aligned with final traffic routes at detailed design stage to ensure adequate levels of illuminance are achieved. The site will be operational 24 hours a day, 7 days a week, but delivery times will be between 7am and 7pm. There will be CCTV coverage throughout the site for security. However the CCTV is planned to not require visible site lighting to operate, therefore light levels will be reduced during the night in the areas that are not operational.

Portable task lighting will be used if and when needed for maintenance purposes. To help understand this report, there is a list of Lighting terminology in section Appendix 1.

2.2 Scope of External Lighting Report

This report has been prepared in order to establish the potential effects of the proposed

development’s fixed lighting installation on the bat conservation areas and the areas

surrounding the site.

The report accompanies the planning application for the proposed Anaerobic Digestion Facility.

2.3 Objectives

The general objective of this report is to assess the impact of a suitable lighting scheme for the proposed site on the surrounding area and environment. Specific objectives of the proposed lighting scheme when fully designed include:

• To limit light pollution and sky glow.

• To limit obtrusive light, spill light / trespass light and glare to neighbouring land and properties.

• To mitigate the effects of the lighting scheme on bats.

• To provide an adequate level of illuminance for the proposed exterior areas, in accordance with the CIBSE guidance and Clients requirements.

• To provide a part-lighting strategy. The routes to the tanks from the main processing yard and areas around the tanks will not be operational during the night, between 7pm and 7am. Routes to the dried digestate and buffer tanks will be lit at dusk till 7pm and from 7am till



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dawn. All other routes around the tanks will rely on vehicular headlights. Lighting shall be switched off in these areas between 7pm and 7am as the client does not require access to any of the tanks to be lit as they will not be used at night. (See accompanying drawings showing lighting to be switched off between 7pm and 7am.) Security lighting is not required. A manual override switch shall be provided for this lighting, located in the gatehouse/reception, for use only in an emergency.

• There will be CCTV coverage for security purposes throughout the site but the CCTV is planned not to require visible light at night to operate but will be of the night vision type, so the colour rendering, uniformity and level of illumination of the site lighting will not be for the purpose of the CCTV installation.

• To provide a suitable lighting control strategy to minimise energy consumption.



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3 Relevant Standards & Guidance

The following standards and guidance have been consulted in preparing the lighting design:

• SLL Code of Lighting 2006

• Society of Light & Lighting Handbook – 2009

• Guidance Notes for the Reduction of Obtrusive Light – ILE, 2005

• Lighting in the countryside: Towards good practice – DoE/CoCo, 1997

• CIE Technical Report, CIE 150:2003 – Guide to the Limitation of the Effects of Obtrusive Light from Outdoor Installations

• CIBSE Lighting Guide 6 – The Outdoor Environment

• BS EN 12464-2:2007 Lighting of work places. Part 2: Outdoor work places



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4 Standards & Guidance Overview

All standards consulted are nationally recognised documents, (some internationally, also)

which deal with all design issues associated with external lighting.

CIE Standards, the CIBSE and the Society of Light & Lighting guidance documents all apply a

common Environmental Zoning system, which is summarised in Table 1 below. It has been

assumed that the site will fall between the classifications of zone E1, (Areas with intrinsically

dark landscapes), and Zone E2, (‘low district brightness area’). This is because the roads e.g.

B3417 are unlit, and surrounding areas include national parks and areas of outstanding natural

beauty, however the site itself is a brownfield site that has previously been used for mining and

was lit throughout the night. There is another adjacent mining site that is still operational and is

also illuminated throughout the night. As the area to be lit lies between two zones categories

the obtrusive light limitation values used will be those applicable to the most rigorous zone, in

this instance it is zone E1.

Environmental Zone Zone Description & Examples of Sub-zones

Rural Environmental

Zone E1

Areas with intrinsically dark landscapes: National Parks, areas

of outstanding natural beauty (where roads are usually unlit)

Rural Environmental

Zone E2

Areas of ‘low district brightness’: outer urban and rural

residential areas (where roads are lit to residential road

standard)

Urban Environmental

Zone E3

Areas of ‘middle district brightness’: generally urban residential

areas (where roads are lit to traffic standard)

Urban Environmental

Zone E3

Areas of ‘high district brightness’: generally urban areas having

mixed recreational and commercial land use with night-time

activity

Table 1- CIE Environmental Lighting Zones

There are also a number of other factors which influence the appropriate design of a lighting scheme, based upon the Environmental Class. These factors are explained in more detail below.

1. Sky glow must be restricted, by restricting the upward light ratio of all light fittings. Table 2, from CIE guidance states the requirements that must be met.



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Table 2 – CIE Recommendations for the limitation of Sky-glow

All luminaires for this scheme will emit 0% upward light, and will therefore meet this objective. An assessment of overall sky glow, including reflected light, has been made of the lighting installation and this illustrates the sky glow effect will be minimal, see drawing E05.

2. Illuminance at windows in nearby properties must be limited to avoid light trespass.

The limiting illuminances for this development are 2 lux (pre-curfew) and 0 lux (post-curfew), as defined in Table 3.

The values in the table are the suggested maximum and need to also take into account the existing light trespass at the point of measurement. The scheme proposed controls the lighting level such that the illuminance levels are below 1 Lux at a distance of 30m from the nearest neighbouring residential property.

Environmental Zones Light Technical Parameter

Application conditions

E1 E2 E3 E4

Pre-curfew 2 lux 5 lux 10 lux 25 lux Illuminance in the vertical plane

Post-curfew 0 lux 1 lux 2 lux 5 lux

Table 3 – CIE Maximum Values of Vertical Illuminance on Properties

3. The intensity of all light sources must also be controlled such that there are no lamps visible from the site boundary exceeding the values in table 4.

Given that all specified luminaires will have clear and defined cut-off angles, and be angled down with the lamp concealed by the luminaire body, there is no possibility of direct glare being experienced by nearby residents.

Environmental Zones Light Technical Parameter

Application conditions

E1 E2 E3 E4

Pre-curfew 2500 cd 7500 cd 10000 cd 25000 cd Luminous Intensity emitted by luminaires

Post-curfew 0 cd 500 cd 1000 cd 2500 cd

Table 4 – CIE Maximum Values of Intensity of luminaires in designated directions

Environmental Zone Maximum upward light ratio ULOR (%)

E1 0

E2 5

E3 15

E4 25



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4. Signage Illumination and brightness of the building façade is also restricted by the standards. However, there will be no illuminated signage and building façades are not intended to be lit as a feature.

Safety in all areas of the site is the primary reason for the lighting provision. The standards and guidance listed in section 3 not only stipulate the necessary requirements to reduce and/or eliminate light pollution, they also specifically detail the minimum illumination levels that should be achieved within the development. These are outlined in section 7.1 of this report.



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5 Assessment Methodology

An appropriate lighting scheme for the site has been assessed using standard industry software Relux. Relux is a computer calculation package which utilizes 3D modelling to model the real world output of chosen light fittings. The results from the computer model produce the contour lines detailed on the accompanying drawings.

The lighting outputs have first been calculated with all the luminaries switched on, representing the ‘worst case scenario’ which will occur between 7am till dawn, and dusk till 7pm, to cover the site delivery hours. A second calculation has been carried out to represent the part-lighting strategy operating from 7pm till 7am. From these calculations, drawings illustrating the illuminance levels throughout the site and at the boundary have been produced so that the lightings scheme’s impact can be assessed. Refer to Drawing E01-E04 for detail. The calculation model (Lux levels on drawing) does not include the planting / hedgerows / trees, however this is accounted for when assessing and making conclusions about the light spill. Light trespass has been assessed and the line of sight from neighbouring residential properties has also been considered. The sky glow impact from the site has been calculated for the ‘worst case scenario’, with all the luminaries switched on. For detail see Drawing E05. Full calculations have been included in Appendix 5.



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6 Baseline Conditions

The proposed Anaerobic Digestion Facility is located within the former Lee Moor China Clay Refinery site near Lee Moor, Devon, operated by Imerys. The site is developed and has lighting throughout, and although the existing lighting is not currently in use, it was previously believed to have been used throughout the night. There are other sources of lighting in close proximity to the site, which includes an adjacent site on the other side of the B3417, which is still operated by Imerys, which has external lighting that is on throughout the night. While the B3417 is “unlit” the impact of all the moving vehicle lights will have its own noticeable impact. The site entrance is currently un-lit and will remain un-lit.

A survey was conducted to establish the extent and types of luminaires that are currently on the existing site. To summarise, the existing lighting installation consists of a mixture of building mounted luminaires at various heights, in some instances utilising arm brackets, posts, and column mounted fittings. There are also three existing luminaires mounted on a tower. Many of the existing fittings are directed at approximately 90º from the horizontal plane, this could potentially be obtrusive and would have resulted in a high upward light ratio, and wasted light and energy. See figures 1- 12 below showing examples of existing luminaires. The luminaires are currently located mainly to serve as task lighting for maintenance. Due to how the site is proposed to be operated in the future by the client this necessitates lighting around the main access routes within the site for safety and amenity, and in the main processing yard and staff welfare / car park areas.

Figure 1



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Figure 3

Figure 4 – Tower Lighting

Figure 2 – lighting on existing main building

Figure 5 – Tower Lighting

Figure 6 Figure 7



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Figure 10 Figure 11

Figure 12

Figure 8 Figure 9



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7 The Proposed Lighting Scheme – Design Approach

The lighting scheme outlined in this report is to be viewed as a lighting design strategy rather than a detailed design solution.

7.1 Recommended Lighting Values

Lighting levels have been designed in accordance with the Clients requirements and to mitigate the sites impact on bats. Consideration has been given to CIBSE Lighting Guides, SLL Code for Lighting 2006 – Obtrusive Light Guide, Guidance Notes on Reduction of Light Pollution, and BS 5489. However, the final agreed illuminance levels in which this report is based upon have been decided by the Client following their risk assessment, method statements and consideration of the site H&S strategy. Recommended Levels The recommended levels according to SLL Code for Lighting – Obtrusive Light Guide (refer to Appendix 2 of this report) are as follows:

• Area Lighting for Lorry Area is 20-30 Lux Maintained Average (horizontal).

• Area Lighting for Loading Area is 50 Lux Maintained Average (horizontal) and 25 Lux Maintained Minimum (horizontal).

The recommended lighting levels according to SLL Code for lighting – General Areas in Outdoor Work Places (refer to Appendix 3) are as follows:

• Walkways exclusively for pedestrians are 5 Lux Maintained Average (horizontal).

• Traffic areas for slowly moving vehicles (max 10 km/h) e.g. bicycles, trucks and excavators is 10 Lux Maintained Average (horizontal).

• Pedestrian passages, vehicle turning, loading and unloading points is 30 Lux Maintained Average (horizontal).

• Lighting requirements for safety in medium risk areas is 20 Lux.

• Lighting requirements for safety in high risk areas is 50 Lux.

The recommended lighting levels according to BS EN 12464-2:2007 Lighting of work places – Part 2: Outdoor work places, are as follows:

• Pedestrian passages, vehicle turning, loading and unloading points is 50 Lux maintained average.

Agreed Levels for this site

• The main processing yard to be lit to 50 Lux maintained average. This area is to be lit 24/7.



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• Staff welfare/ car parking area to be lit to 10 Lux maintained average. This area is to be lit 24/7.

• Access routes to the dried digestate store and buffer tank to be lit to 10 Lux maintained average during site delivery times i.e. 7am till dawn and dusk till 7pm. After these times, throughout the night, a part-lighting strategy will be adopted to switch off all of the access route lighting as these areas will not be used during the night. Where there are bat foraging flight paths on the north western side of the site, outside of the lease boundary, close to the shared vehicular access route there is no proposed fixed lighting.

7.2 Strategy for Minimising Obtrusive Light, Mitigating the Effect on Bats and Reducing the Visual Impact of the Lighting Scheme

Careful consideration has been given to reducing obtrusive light during the hours when the site is lit and the visual impact of the lighting scheme during the day, whilst maintaining an adequate level of illuminance for its application on the site. Particular attention has been paid to minimising the presence of the scheme and any intrusion, glare or sky glow produced by the scheme. A majority of the luminaires are to be column mounted, some columns will be base-hinged to allow for maintenance in areas where access may be difficult. The columns are generally spaced between 20-25m apart and will be 5m high. This is the lowest level possible to reduce visual impact whilst being high enough so that delivery vehicles can safely access the site. All luminaires have 0% upward light output ratio. The column mounted luminaires have been chosen to be as inconspicuous as possible. Arm brackets shall have 0º uplift. They will also be fitted with flat glass to reduce the visibility of the light source. Wherever possible luminaires are to be orientated towards the site, away from the land outside the site to make them less intrusive to neighbouring properties and wildlife. Luminaires have been chosen that have good light control and cut off angles to reduce light spillage. Building mounted luminaires have been proposed in some areas, mainly to light the main processing yard. The building mounted luminaries will be angled at a maximum of 10º above horizontal which will minimise sky glow whilst providing a wide light distribution at ground level reducing shadows produced from obstructions i.e. lorries, parked for loading. The luminaire itself has 0% upward light ratio, and the beam spread is controlled to within 50º from the vertical when the glass is horizontal. This particular luminaire can be tilted 10º from the horizontal and still have a 0% ULOR. It is also fitted with flat glass to reduce the visibility of the light source.

According to the Planning Application Environmental Statement B6, (refer to drawing B6.2) there are no bat roosting opportunities recorded in the site, but there are foraging bats. It is recommended by the Environmental Statement that external lighting is minimised and directed away from the bat flight lines adjacent to the northwest boundary and the trees near the road on the eastern boundary. This has been addressed by proposing to have no fixed lighting close to the northwest boundary for the shared access route, it is proposed to use only vehicular headlights along these routes for access between 7pm and 7am; and there is no lighting proposed for the site entrance. The Environmental Statement also recommends that lights are low wattage, with low UV component, directional beams, and timed to include periods of darkness. All of these items have been addressed. All luminaires utilise high pressure sodium lamps which have a low UV component. The majority of the luminaires utilise 70W lamps, with some utilising 250W lamps in the main processing yard due to the large area. Mounting heights have been kept to a minimum; most luminaires are mounted at 5m. Directional luminaires have been specified with 0% upward light output ratio. In the areas where it has been possible, a



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part-lighting strategy is to be adopted to switch off approximately 45% of the total exterior lighting. The main processing yard and staff welfare area/ car park is required to be lit 24/7.

Currently the site entrance is unlit and it will remain un-lit, as vehicle headlights will be used to access the site.

A luminaire will be mounted at the top of the existing tower (see figure 4) in a similar position to the existing fitting. The new luminaire will be utilised to light the pipe bridge, approx 9-10m mounting height. This luminaire will be directed at the pipe bridge and will be manually switched on/off as and when required.

7.3 Strategy for Luminaire Types

High Pressure Sodium (SON) lamps shall be utilised throughout the site, as recommended by the Environmental Statement, to mitigate the impact of the lighting scheme on the bats. The SON lamps will provide a Colour Rendering of approx 23 Ra which is acceptable for the application. Using this type of lamp will provide an energy efficient solution and will be Building Regulations Part L compliant. These luminaries, or equal and approved, have been chosen as they have been designed to be anti light pollution and low glare with good levels of efficiency between 75 – 80% for the chosen lamp types and zero upward light output ratio. All the luminaries are IP65-IP66 rated and impact resistant. See Appendix 4 – Schedule of Luminaries and Details.

7.4 Part-Lighting Strategy and Luminaire Controls

To minimise the light impact on surrounding areas as much as possible a part-lighting strategy will be adopted. This will mean that approximately 45% of the exterior lighting will be switched off from 7pm till 7am. See drawing E03 & E04 showing illuminance levels 7pm till 7am. Photocells and programmable time clocks are to be used to control the exterior lighting so that no luminaries will be left on during daylight hours or when they are not required. It would be beneficial to have manual override control of the external lighting at the gatehouse/reception. The only exception to this is the luminaire for the pipe bridge which will be manually switched on/off as and when it is required.



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8 Assessment of the Impact of the Lighting Scheme

Drawing E01-E04 shows the lighting scheme for the site, with the illuminance levels shown throughout the site. The red line on the drawings represents 5 Lux and the purple, 1 Lux. The drawing shows that at worst case with all the luminaries switched on, there will be no light spill outside of the site and that there will be minimal impact on the bat flight paths from the lighting scheme. Adequate levels of lighting have been achieved on the site with minimal effect on the surrounding area. There will be zero illuminance from the proposed lighting scheme outside the site. The Upward Light ratio of the proposed installation is zero and will be much better than the existing luminaires and surrounding lighting installations. Drawing E05 illustrates the additional sky glow caused by the reflected light produced by the lighting scheme. This calculation was provided by a simulation of a measuring reference plane approx 50m above the ground. The results show an average illuminance above the site of 0.2 Lux simulated for the ‘worst case scenario’ with all the lights switched on. This means that when the site is fully lit the sky glow will be approximately equivalent to the light produced by a full moon at 0.3 Lux, which is low. The sky glow above the surroundings of the site will be negligible. The drawings show how well the lighting will be contained within the site, and with the existing landscape and distance to neighbouring properties, there will be no light trespass.



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9 Conclusions

By adopting the lighting strategy including criteria, luminaries, switching methods, lamp types, etc. outlined in this report it can be concluded that:

• The impact on bats has been minimised as much as possible due to the position of the luminaires and luminaire & lamp types. Where possible luminaires will be switched off after 7pm where bat flight paths are known, as recommended in the Environmental Statement.

• The scheme proposed controls the lighting level such that the illuminance levels are below 1 Lux at a distance of 30m from the nearest residential property.

• Lighting as proposed would not cause excessive glare to neighbouring domestic properties from this site.

• The majority of the luminaries will not be visible to neighbouring domestic properties.

• The effect on the night sky will be minimal inside the site and zero outside the site.

• The lighting scheme will be energy efficient utilising luminaires with an efficiency of between 75-80%, combined with energy efficient lighting controls.

• An adequate level of lighting can be provided for site tasks, amenity and security, whilst maintaining a minimal impact on the site surroundings, environment and neighbouring properties.

Documents

External Lighting Assessment - · PDF filedeveloper’s designers when undertaking the full external lighting design of the site. ... External Lighting Assessment August 2011 . Anaerobic