Lighting the way

Light pollution, defined as the excessive or inappropriate use of external visible lighting, has been an unwanted and unnecessary consequence of our rapid urbanisation for the best part of the 20th Century. It is only in the past decade, however, that awareness and international pressure to legislate against it has become so widespread.

In the United States, for example, the International Dark Skies Organisation has been at the forefront of efforts "to preserve and protect the night-time environment and our heritage of dark skies through quality outdoor lighting". Since 1998, the IDS has been educating the public and lobbying local and federal governments about the benefits of good lighting practices.

In Japan, the city of Bisei, home of the country's national observatory and planetarium, passed a light pollution ordinance to ensure compliance with policy to preserve dark star-lit skies. In an effort to reduce existing light pollution levels, the city also provides subsidies of up to two-thirds of the cost of installing, modifying or replacing offending lights.

In February 2002 the Czech Republic became the first country in the world to enact national legislation to eliminate light pollution. Following suit, in April 2006, the UK's Clean Neighbourhoods & Environments Act 2005 came into force, allowing Local Authorities the power to impose orders to "put right" badly designed lighting schemes and to impose heavy fines – up to £5000 for residential premises and up to £20,000 for businesses – failing to do so.

Looking at this trend, security professionals need to begin raising awareness of the issue, whilst benefiting from the business opportunities it presents. Both commercial and residential security lights and the practice of flood lighting as a preventative security measure have been identified by campaign groups as major contributors to light pollution.

What exactly is light pollution?

Light pollution is any external visible light which causes a nuisance or detriment to the surrounding area. Caused when misdirected light leaks out of its intended target area, either into neighbouring properties or up into the sky, light pollution destroys our views of the night sky, can affect quality of life, and wastes energy. The electricity used to power this unnecessary light is generated by burning fossil fuel, which in turn causes acid rain and increases carbon dioxide emissions into the Earth's atmosphere.

Light pollution can be categorised into three distinct types: sky glow, glare and light trespass – when light spills beyond the boundary of one property and into a neighbouring one. Often the result of poorly designed or misdirected security or flood lights, light trespass is at best distracting and annoying, and at worst can cause long term health problems including insomnia and anxiety and result in the reduction of property values.

What's the solution?

The security industry has been identified as a prime offender in the fight against light pollution. It is important to recognise however that light only becomes a problem when it is excessive, poorly designed or badly installed. Security professionals need to review both existing and future installations and consider the quality of light used, the amount of light used, the need for it and where it is directed. The key is not "no light" just the "right type of light".

Bright light can help to allay the fear of crime but cannot actually prevent it – floodlit premises are routinely broken into and crimes committed under security lights. In a recent independent study by the Home Office, known offenders were asked to identify situational factors which influenced their decision whether or not to target a particular building. While 89 per cent quoted the "presence of a CCTV camera on or near the building" not one stated the presence of a so-called "security light" as a deciding factor.

The vast majority of crime takes place under the cover of darkness. The practical answer for effective night-time security is a combination of detector driven, low watt visible lighting sited at strategic points in and around the installation, coupled with a comprehensive 24/7 CCTV surveillance system, illuminated by infrared.

Low watt, directional and discreet, infrared is specifically designed to work within the camera’s dynamic range, maximising its effectiveness under low light conditions. Infrared does not cause light pollution at any wavelength. At lower wavelengths (730nm) all that is visible from an infrared lamp is an unobtrusive red glow, at 830nm a very dull glow is visible and at 940nm the light becomes completely overt.

There is a common misconception that infrared is a more expensive, specialist type of illumination. In actual fact the opposite is true. Installing visible light in a way which minimises light pollution requires multiple lamps set up at regular intervals. Take into account cost of installation, maintenance and the significant cost of operating these overpowered, wasteful lamps, and costs will soon spiral.

By contrast, energy efficient infrared illuminators are specifically designed for long life and low power consumption. The result: lower electricity costs, longer periods between maintenance call outs and lower cost of ownership for the end user. Infrared illuminators can be sited on or around any type of CCTV set-up, including static cameras, PTZs and fully functional domes, to dramatically improve performance under low light conditions.

Installation advice

Whilst no one is suggesting we do away with visible light altogether, security professionals need to ensure they are offering the best solutions to their customers. Often too much light can be as much of a problem as too little. Typical 500W security lights are vastly overpowered, wasting electricity and ultimately money for the end user. The Institution of Lighting Engineers recommends using no more than a 150W light – when you consider that most lighthouses use only 1000W bulbs, it is clear why these so called "security lights" waste so much light and electricity.

• Keep it down – Angle outdoor lights downwards, use minimum watt bulbs, fit hoods or shields to minimise light spill and ensure lights are only switched on when it is absolutely necessary. An uncovered light will cast approximately 30 per cent of the light it generates skyward, effectively wasting light and the electricity taken to power it. Installers should take the opportunity to raise this issue of light pollution with existing customers and benefit from retrofit opportunities. Being able to discuss the issue knowledgably and offer customers a practical solution demonstrates a forward-thinking company well abreast of the latest issues in the industry.
• Keep it controlled – Using a PIR as opposed to continuous floodlighting means light will be triggered only when it is needed, reducing running costs and light pollution, whilst having the added benefit of alerting occupants to any potential intruders. Prevent PIRs "crying wolf" by siting them well away from heat sources and straying pets. Most newer PIRs are supplied with the technology to differentiate between animal and human activities.
• Keep it off – Most PIR sensors can be adjusted to stay on for the minimum time necessary, saving money and minimising light spill into neighbouring properties.
• Keep it under watch – Bright visible light will only give the illusion of safety. In some cases it can actually assist intruders by making their presence seem legitimate – after all a person strolling purposefully around a well lit area will appear less suspicious than someone moving around in the dark carrying a torch. Contrary to popular belief most criminals are brazen and quite happy to have a well lit area in which to go about their business.

We heard about one car dealership, in a residential area, that had 18 vehicles broken into even though the forecourt was flooded with light. The owner relied on the public to report any suspicious behaviour. He also wrongly assumed that no criminal would dare commit a crime in such a well lit area. In this particular case all the intruder did was pull on a pair of overalls and go about his business, and although there were witnesses to the crime no one reported it, assuming he was an employee working late.

In comparison an effective 24/7 surveillance system illuminated by invisible infrared would have been witness to the event without alerting the intruder to the fact he was being watched. The resulting video will do more to help apprehend a criminal and secure a conviction than any "security light" ever could. Using the latest remote access IP technology he could have even been caught in the act.

What should the industry do?

Responsible security professionals need to champion this cause and take advantage of a swell in public opinion to exploit opportunities with new and existing customers.

Philip Lynskey, managing director of Wakefield-based Calder Security, was recently asked to install a CCTV system at a warehouse adjacent to a residential area.

"One elevation of the building is adjacent to a residential area and the client has asked us to secure the spot with CCTV but avoid light spill," he says. Lynskey has been in the business since 1974, but this is the first time that light pollution has been raised as an issue by the client.

"We've brought it up ourselves with customers in the past, particularly when dealing with residential installations, but this is the first time a client has talked to us about it from the outset," he says. The message is clear; the time to think about phasing out wasteful lighting and reducing light pollution is now.