House of Commons - Science and Technology

Select Committee on Science and Technology Seventh Report

3 WHAT CAUSES LIGHT POLLUTION?

71. We have received evidence on the need for lighting for social, security and safety reasons. The main issues raised were:

The need to prevent road accidents by providing good definition of the roads through street lighting.

Providing light on roads, pavements and pathways promotes a feeling of safety and well being for pedestrians and road users. Sympathetic lighting can illuminate and enhance architectural features of towns for the enjoyment of citizens.

Lighting deters and reduces crime.

72. Evidence received has shown that street lighting has been effective in reducing the number of road traffic accidents.[121] It is somewhat beyond the remit of this inquiry to investigate whether lighting does engender a feeling of safety for pedestrians at night or whether lighting does indeed prevent crime. A number of memoranda questioned the accuracy of the Home Office survey which concluded that lighting does prevent crime.[122] It is interesting that the Home Office-sponsored Crime Reduction Website warns that over powerful infra red sensor activate security lighting creates dark shadows which make it easier for criminals to enter a property unseen.[123] The UK's streets are now more brightly lit than ever, and yet crime levels have risen since the days when street lighting was turned off at night. There is a suggestion that whilst people may feel safer, in statistical terms they may not actually be any safer. The Government told us that they were due to highlight the role that good lighting may play in reducing crime in its good practice guidance on "planning out crime", due to be published later in 2003.[124]

73. Witnesses have submitted written papers to the Committee on the adverse effect of lighting on crime.[125] Other memoranda has commented that more lighting at night enables criminals to see what they are doing—for example, would graffiti artists be able to work in the dark? Without commenting on the validity of this evidence, the Committee notes that in the August 2003 electricity blackout in parts of North America, the feared crime wave did not materialise. Similarly, in 1998, Auckland was victim to a black out lasting several weeks. A police inspector was reported as saying "It's almost a crime-free zone. The normal levels of muggings, violence, fights, burglary and robbery have just not happened."[126]

74. We consider that whilst the role of efficient and well positioned street lighting in reducing accidents has been proven, the evidence relating to the correlation between lighting and crime is not conclusive. This link is outwith the remit of our inquiry, but is an area that merits further research. We look forward to seeing what new evidence the Government has received on the role of lighting in the reduction of crime when its good practice guidance "planning out crime" is published later this year. However, we believe that the impact of lighting on crime should be only one of a number of factors that is considered in the determination of Government policy on lighting.

LIGHTING EQUIPMENT TYPES

Taken from Lighting in the Countryside:

Lamps: Gas discharge lamps can be split into two types. The first type produces ultra-violet radiation from the gas discharge which is converted into visible light through a reaction with a phosphor coating on the glass bulb. This type includes the tubular fluorescent lamp used in most commercial offices and the growing number of small 'energy saving' compact fluorescent lamps available for the home. The second type, which produces visible light directly, includes metal halide, high pressure sodium and low pressure sodium lamps. All gas discharge lamps require extra electrical components, both to switch on the light and throughout the period they are working. They have relatively high efficiencies and long lives, but varying colour appearance and rendering capabilities.

Luminaires: While it is possible to run most lamps in free air, it is normal practice to fit them into some type of luminaire. The luminaire can provide protection for the lamp against damage and/or the weather and may protect people in the vicinity against burning or electric shock. In the case of gas discharge lamps, the luminaire may act as a container for the lamp control gear, and most importantly, it may act as an optical device for controlling and directing light, helping to reduce the risk of light trespass.

The two types of luminaire commonly used in exterior lighting are the fixed angle and variable angle luminaires. The former is designed for use in a fixed orientation, such as on the top of a lamp post or built into the wall of a building, while the latter is fitted with a movable bracket, allowing the installer to direct the light beam to the direction required. In many cases it is the choice of luminaire which will determine the impact of the light. Luminaires which provide full horizontal cut-off (HCO) can minimise sky glow, and many have reflectors which control and direct the light beam with varying degrees of accuracy and effectiveness.

Street lighting

75. The ILE told us that there is a predominance of low pressure sodium (LPS) lighting (sometimes referred to as SOX lighting) in the UK. This was installed in the 1970s as it was considered to be the most energy efficient at that time.[127] Its disadvantages are that the light is difficult to control because of the physical size of the luminaires and that it causes the unpleasant orange tinged glow. The ILE estimate that 45% of street lighting in England is of that type and consider that the figure is probably the same for Wales, Scotland and Northern Ireland.[128] Some astronomers told us they preferred LPS lighting as it is easier to filter out, but most astronomers, the ILE and the Highways Agency advocate the disuse of LPS lighting in favour of high pressure sodium (HPS) lighting (also called SON lighting). The Highways Agency told us that it "carefully considers the overall environmental impact, energy efficiency, maintenance and aesthetics of its lighting installations before implementing a scheme."[129] HPS lamps can be more controlled and can direct the light downwards whilst spreading it along the road - enabling the maximising of spacing the light fittings. It is also possible to use other white coloured light sources to reduce lighting levels on small areas such as housing estates.[130]

76. The shape of the lamp is also important - lamps with fully curved bowls tend to spill more light above the horizontal. Whilst the ILE recommends that all lights be designed so that there is no upwards light from them, it has concerns about Full Cut-Off lighting (FCO) being used for all lighting.[131] ILE believes that FCO lighting is not suitable for all street lighting, and should be kept for dark rural areas and areas near observatories. For general street lighting they suggest:

132

77. For lighting in residential areas the ILE suggests that FCO is not suitable, but that the low pressure sodium lighting should be replaced with high sodium pressure lighting. The ILE estimates that better controlled modern lighting, for example shallow bowl luminaires, could reduce the amount of light pollution from the replaced lights by up to 20% without any difference in running or maintenance cost to the old LPS systems.[133]

78. Street lighting in the UK is under Highways Agency or local authority control, depending on the type of road, or under the control of the devolved legislatures.

HIGHWAYS AGENCY CONTROLLED STREET LIGHTING

79. The Highways Agency lights approximately 30% of its 9,380 km strategic motorway and trunk road network, using a variety of luminaires.[134] A road is only lit by the Agency if an economic assessment shows that lighting will reduce the number of accidents. The Agency told us that lighting can reduce the number of night time accidents by up to 30%.[135] Before lighting is installed or renewed, the Agency has to hold a full assessment of the environmental impact considerations in accordance with the Department for Transport's "New Approach to Appraisal" Document.[136]

80. Approximately 35% (51,000) of luminaires under the Agency's control are LPS, and the remaining 65% (94,000) are HPS with 50% having FCO or flat glass diffuser luminaires. The Highways Agency intends gradually to replace all of its lights with more environmentally friendly lights - using both HPS and FCO lighting. The framework for replacement is over the next 10-15 years.[137] They acknowledge that the HPS lighting will not bring any energy savings, but will better control the level and spread of light.[138]

81. The Agency told us that it supported a number of research projects into light pollution, and was running trials on the reduction of lighting levels on roundabouts.[139] The Agency was also able to work with the ILE, the devolved assemblies and local authorities on the issue of improving road effectiveness as it sat on the Department of Transport's Lighting Board. The 1998 White Paper "A New deal for Transport - better for everyone", states that "where lighting is essential, it should be designed in such a way that nuisance is reduced and the effect on the night sky is minimised." It appears that Transport is one Department that is taking light pollution seriously and is implementing changes through the Highways Agency.

82. We welcome the fact that both the Department of Transport and the Highways Agency have given due consideration to the issue of light pollution. The Highways Agency has shown forward thinking in its gradual replacement of luminaires, and in giving environmental considerations top priority. It should be congratulated for its work with the lighting industry and with the Department for Transport's Lighting Board, to improve the efficiency of lighting throughout the UK. It should continue to work with local authorities to "spread the word" about light pollution and the benefits of High Pressure Sodium lighting. We look forward to viewing the results of various research projects into the effect of light pollution that the Agency has contributed to.

STREET LIGHTING UNDER LOCAL AUTHORITY CONTROL

83. Whilst the Highways Agency has control of approximately 145,000 street lights, roughly 4,355,000 lights are under local authority control. Much of this lighting is LPS, over 30 years old and in need of replacing.[140] The Fifth Report of the Transport Committee of Session 2002-2003 (HC 407-1) stated that there had been uncertainty over the true extent of the maintenance backlog. Local authorities had been asked by the Department of Transport to determine the condition of their lighting by July 2003.[141]

84. The Government is currently making available £300 million in PFI credits for local authorities outside of London to invest in street lighting over the next three years, and £80 million to local authorities within London.[142] When asked whether local authorities were receiving guidance from Government on the type of lighting they should be installing, the Minister for Housing and Planning replied:

143

85. ODPM later clarified that these documents were the Department of the Environment's 'Lighting in the Countryside' and Department of Transport's 'Road Lighting and the Environment', and that table 8.4 of 'Lighting in the Countryside' highlights other guidance available for lighting roads and pathways, including Department of Transport's Design Manual for Roads and Bridges Vol. 10 and British Standard 5489, 'General Principles of Road Lighting', 1992.

86. These guidelines are too diffuse to be of any real significance or help to a local authority. The Transport White Paper says "where lighting is essential, it should be designed in such a way that nuisance is reduced and the effect on the night sky in the countryside is minimised." It does not tell a local authority how this could be done.[144] BS 5489 says "in some cases artificial lighting can be obtrusive at night. This applies especially to rural and open spaces where the lighting can be seen as an intrusion into an otherwise darkened environment. In addition light above the horizontal should be minimised as it is wasteful and increases sky glow." It then draws attention to the IAU/CIE publication providing information on lighting in the vicinity of astronomical observatories.[145] Again, there is no real Government guidance of the type and design of light that should be used on streets and roads. 'Lighting in the Countryside' gives options available but the document is clearly labelled "The content of the Guide should not be taken to be a definitive statement of Government policy […] Although this report was commissioned by the Office, the findings and recommendations are those of the authors and do not necessarily represent the views of the Office of the Deputy Prime Minister."

87. Street lighting that is being replaced by local authorities now will have a life expectancy of between twenty five to thirty years. If a local authority installs the 'wrong' type of luminaire, the Government will have lost an ideal opportunity to modernise street lighting, improve efficiency and reduce light pollution.

88. The Government must act now to ensure that every local authority about to invest in new street lighting is well informed of the properties of modern luminaires and the issues of light pollution. If the Highways Agency, backed by the Department of Transport, has taken a policy decision to use high pressure sodium lighting, with full cut off and shallow bowl luminaires in its own replacement of street lighting, then the Government should issue clear guidance to local authorities that these types of lighting are believed to be the most suitable lights available at this time. British Standards codes of practice and guidance should be updated accordingly.

89. Firm guidance and direction must come from the Government on this issue. Relying on piecemeal guidance, published some years ago, to inform important local decisions such as the replacement of the street lighting systems is not an acceptable attitude from the Government which is spending £380 million on this project.

90. Local authorities which have not already invested in new lighting must be strongly advised to install High Pressure Sodium lighting, the design of which should be shallow bowl or fully cut off lighting as appropriate. Local authorities should also be required to follow ILE and CIE guidelines when deciding where to install Full Cut Off lighting, with an obligation to protect observatories, dark rural areas and parkland within their jurisdiction.

ENERGY SAVINGS OF STREET LIGHTING

91. Although BAA and CPRE have both submitted evidence that the changeover to FCO luminaires would create energy savings, the ILE do not fully support this idea. BAA suggests that the total amount of wasted light (pointing above the horizontal rather than onto the street) from street lights amounts to 0.33 of a gigawatt a year.[146] Whilst the ILE do not dispute that this amount of light is wasted through inefficient lighting systems, they question the energy savings that could be brought about by the installation of FCO luminaires. Instead, the ILE suggest that the modernising of street lighting alone will bring about greater energy efficiency due to the advances of lighting technology in the last 30 years, but that even controlling lighting levels and better maintenance will not bring the energy savings suggested by the BAA.[147] We remain unconvinced that modernising street lighting alone will bring significant energy savings, but with pressure from Government, the lighting industry will respond to the need to provide more energy efficient and less light polluting luminaires. Whilst energy saving targets are important, the Highways Agency and local authorities must ensure that luminaires under their control only direct light where it is needed in order to start a trend in the reduction of light pollution.

The other main causes

92. The other types of lighting which have been described as the most obtrusive by the evidence we have received are listed below.

DOMESTIC AND INDUSTRIAL SECURITY LIGHTING

93. In most cases, no planning permission is necessary for domestic or industrial security lighting. Only free standing structures carrying lighting fixtures are deemed 'development' under the Town and Country Planning Act 1990, and therefore subject to possible planning conditions. Individuals and small businesses are able to buy over-powerful security lighting, install it incorrectly and shine 500 watts through their neighbour's windows, or into their neighbour's gardens without any control. Sales of 500w lights rocketed in the 1980s and 1990s.[148] These lights were nicknamed 'rottweiler' lights by Libby Purves, and can make astronomical observations difficult from hundreds of metres away.[149] The Institution of Lighting Engineers (ILE) produced a leaflet entitled "Domestic Security Lighting, Friend or Foe" in recognition of the growing problems caused by this lighting. This leaflet advises those buying security lights:

150

94. Rather than the 500w tungsten halogen lights, particularly those with Passive Infra Red (PIR) sensors which detect movement and mean the light flicks on and off all night, the ILE recommend low wattage compact fluorescent lamps (9/11w and 600-900 lumens) which give off gentle, soft illumination and can be left running all night if required. According to the ILE, security lighting is the area of lighting in which there are true energy savings to be made, if the public could be persuaded to use alternatives to the 500w lights.[151] The BAA estimate that a one kilowatt light left on for twelve hours every night will result in CO₂ emissions from power stations of 3.5 tonnes a year, whereas a 100w light left on for the same time will produce 0.35 of a tonne per year of CO₂ emissions.[152] It is clear that there are significant potential energy savings to be made in the area of security lighting by reducing the amount of light pollution emitted from them.

95. We asked B&Q and Homebase to give details of their light pollution policies. Only B&Q replied; however, CPRE report that Homebase did stock a 'Dark Sky Friendly product' and Focus Do it All stocked mostly 150w lights.[153] B&Q's memorandum to the Committee states that they are keen to contribute towards the reduction of light pollution and have been promoting a range of lighting specifically designed to reduce stray light. B&Q's annual turnover of security lights is £12.5 million, and £2 million of this is made up of 500w security lights. They stated that they were reconsidering the price architecture of 500w lights as these lights are £1 cheaper than 150w lights. B&Q consider they fully discharge their responsibility as the majority of B&Q floodlights are fitted with an anti light pollution bracket preventing the customer angling the light upwards, and instructions with information about light pollution are included in the packaging of all security lights.[154]

96. Based on B&Q figures alone, and estimating that the average 500w light costs £10 or less, at least 200,000 500w lights are being sold and installed every year, and the overwhelming majority of these lights are far too bright for their purpose. We have received evidence that despite the best efforts at negotiation, many householders, astronomers or not, are unable to persuade their neighbours to reduce the power of the lighting or to re-position it.[155] Whilst it is possible to angle 500w security lights correctly, we consider that for normal domestic purposes, they are energy-inefficient and liable to cause a nuisance.

97. The Government in its memorandum indicated that it was not in favour of controlling the designs of lighting available to the public.[156] However, when questioned on this subject the Minister for Housing and Planning told us that the Government had looked at the issue of only permitting the use of approved lighting devices which will not cause pollution:

157

98. Whilst it is commendable that retailers have considered the issue of light pollution, leaflets inside the packaging of security lights will not alert customers to the benefits of a less powerful light before they decide which security light to buy. Providing the Institution of Lighting Engineer's Guidance on security lighting, or a version thereof, alongside the displays of security lighting would greatly assist the customer. However, it will not prevent incorrect installation of lights. Only legislation either banning the sale of 500w lights as security lighting, or the designation of light as a potential statutory nuisance will ensure that householders suffering from their neighbour's overspill of light have a remedy: we favour the control of obtrusive light through statutory nuisance legislation.[158]

FLOODLIGHTING OF SPORTS FACILITIES

99. The floodlighting of stadia, golf driving ranges, football pitches, and tennis courts can cause light pollution for miles around. Sport facilities are important amenities to communities, and floodlighting of facilities enables them to be accessed by a greater number of people at hours convenient to the modern workforce. However, the lights must be properly installed and positioned so that the beams do not cause glare or nuisance to others. Planning Policy Guidance Note 17 (PPG17): Planning for Open Space, Sport and Recreation, suggests that local authorities should take into account the visual impact of the lighting towers during the daytime. Planning permission is required for floodlighting of this nature, and so the positioning and strength of new floodlights can be controlled by local authorities should they wish to do so - unfortunately they often do not. We received evidence from the ILE that many sports facilities had recently received lottery grants to install floodlights, leading to a number of complaints from people living in the surrounding area whose properties were lit up by cheap, badly installed floodlights.[159]

CAR PARKS

100. Witnesses were particularly annoyed with the tendency of companies, particularly supermarkets to keep empty, locked car parks illuminated all night. Unfortunately many car parks are lit by globe lighting chosen for its daytime appearance rather than its efficiency. Witnesses considered this all-night lighting to serve no purpose and to be both wasteful and a nuisance. The ILE told us "[globe luminaires] much loved by planners and architects, are some of the worse for causing light pollution and in many cases actually emit more light upwards than downwards."[160] It is possible to modify globe lighting to cause less light pollution, and astronomers have reported that some companies have responded well to requests to turn off lighting at night or to modify existing lighting.[161] The only way to ensure that any lighting scheme of this nature is properly controlled is to ensure that planning conditions on the style and type of lighting to be used in a development are imposed before planning permission is granted.

FLOODLIGHTING OF BUILDINGS AND MONUMENTS

101. Four hundred churches received grants from the Millennium Commission towards floodlighting projects across England.[162] Unfortunately, like that used on many other buildings, poorly designed floodlighting is usually positioned on the ground shining upwards into the sky, missing most of the building it is meant to be illuminating. Lighting structures and installations of this kind may require planning permission if they are substantial, or alter the building's external daytime appearance, or if they are new developments in their own right. The case of Kensington and Chelsea Borough Council v CG Hotels and Another shows how a local authority failed to force the removal of ground and first floor floodlights shining on a hotel, as the judge decided that the installations were invisible during daylight hours, and the lighting was a consequence of electricity passing through the apparatus, rather than the apparatus itself.[163] As it was not a listed building, planning conditions or controls on lighting would not have applied in this case, but a statutory nuisance of lighting could have applied if the hotel were causing a nuisance to its neighbours.

102. Whilst we agree with the Commission for Architecture and the Built Environment that sympathetic and well positioned lighting can add to the public enjoyment of towns and cities; it is a questionable use of money to floodlight buildings all night long.[164] For example, the Palace of Westminster is only floodlit until midnight.[165]

103. Those responsible for floodlighting buildings and sports facilities and those companies lighting car parks should consider whether there is any need for lighting after 11pm or midnight. We recommend that, when giving planning permission to plans for new buildings with floodlighting, new floodlighting systems or new car parks, local authorities should impose conditions relating to the type of lights that are appropriate, how they should be positioned and the timing of the lighting to ensure it is not obtrusive to those around it and that it does not contribute to energy wastage.

SHINING EXAMPLES (AND OTHERWISE)

104. The central pages of this Report show photographs of lighting submitted by witnesses. Some are examples of skyglow and of badly installed or positioned lighting that has caused glare and nuisance. Other photographs show correctly positioned street lighting and security lighting.

121 Ev 231, 81 Back

122 Farrington and Welsh, Effects of improved street lighting on crime: a systematic review, Home Office Research Study 251 (2002). Back

123 http://www.crimereduction.gov.uk/burglary45.htm Back

124 Ev 225 Back

125 Ev 185, and P R Marchant, The Claim that Brighter Lighting reduces Crime is Unfounded, 2003 and LPA 88, Barry Clark, Outdoor lighting and Crime, 2002. Back

126 Light pollution, Responses and Remedies, p 59 Back

127 Q 86 Back

128 Q 90 Back

129 Ev 231 Back

130 Q 86 Back