Nigel Parry, technical services manager, Institution of Lighting Professionals – the UK and Ireland’s largest professional lighting association – looks at the the latest options available
The street lighting sector has traditionally been a fairly slow moving industry with light sources initiating change in the sector.
The first gas lamps on London’s Pall Mall in the 19th century gave way to the use of the filament electric lamp in the same types of columns and lanterns. The introduction of mercury discharge lamps before World War II started a new revolution which has seen the launch of sodium lighting – both low and high pressure coming to dominate our streets (about 90 per cent of the UK is lit with sodium lights).
In 2002 an update to British Standards allowed a drop of a lighting class when using a white light source. This has encouraged manufacturers and users to develop new white light lamps and where they have been deployed has seen a saving in energy, as well as the quality of light, and by using new lanterns with high quality optical control a significant reduction in sky glow over the cities such as Derby where its wholesale deployment has been seen.
More recently, however, the rapid advancement in technology has introduced two new opportunities for a more responsive and energy efficient street lighting system in the UK.
The first of these is the introduction of white light light emitting diodes (LEDs). These were first developed in Japan in the 1990s but only the last few years have seen them develop enough to equal the lumen of light per watt (L/w) of electricity produced by the more usual discharge lamps sources. The LEDs are currently delivering around 100-120 lumens per watt and can easily light most residential roads to the levels required by British Standards.
As with any new technology being introduced, the costs are high. A typical residential road street light lantern will cost under £200 whereas a new comparable Led unit will cost from £400 upwards. However, the technology is rapidly changing with 150 L/w promised by the end of 2011 and prices set to drop significantly over the next few years. At some point the performance and price will be right and the use of LEDs will take-off. Indeed a private finance initiative (PFI) contract in Birmingham has started to change some 40,000 street lights to LEDs over the next five years.
Central Management Systems
The other tool in the box is something termed Central Management Systems (CMS). In the UK this is primarily a wireless communication system that allows a central control point (say city hall) to communicate with every lamp on the network. The system can switch each lamp on and off at the optimum time but also can deliver a number of other benefits that are new.
These include the ability to vary the light levels by dimming the light when there is little demand, such as in the middle of the night, but keep a safe level of lighting instead of switching off, thereby saving energy. It can also be reactive so it can bring on the lights to full power in case of an emergency or in town centres late at night when high levels of light are required when night clubs are closing their doors. It is also possible that these systems can detect when a lamp is about to fail and send an instruction to a contractor to replace the lamps, thereby ensuring no dark spots on the streets.
Thus the advent of using lower levels of white light, new Led technology and a control system is making the UK streets a better lit environment with less light pollution and saving tonnes of CO2.
The Institution of Lighting Professionals (ILP) is the UK and Ireland’s largest and most influential professional lighting association, dedicated solely to excellence in lighting. Founded in 1924 as the Association of Public Lighting Engineers, the ILP has evolved to include lighting designers, consultants and engineers amongst its 2,200 strong membership.
The key purpose of the ILP is to promote excellence in all forms of lighting. This includes interior, exterior, sports, road, flood, emergency, tunnel, security and festive lighting as well as design and consultancy services. The Institution is a registered charity, a limited company and a licensed body of the Engineering Council.
Regional meetings are held regularly around the two countries giving members a chance to see presentations on the latest issues in the lighting community. The ILP organises a wide range of conferences, seminars and courses. The ILP’s annual conference goes from strength to strength with delegates attending each year to discover more about how to continuously achieve excellence in lighting.
The ILP also arranges one-day Lighting Roadshows around the UK to promote its message.
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