Light emitting diode (LED) technologies have applications in traffic signalling, minor road streetlighting (still in development), major road streetlighting (still in development), solar lighting, and park and car park lighting. Eventually LEDs will be used for most lighting applications.
While LEDs have been used in traffic lighting for some time, their application to park, carpark and street lighting is a recent development. LED street lights are not yet commercially available in Australia but they are in the US - indeed, the city of Ann Arbor, Michigan has recently committed to converting all of its downtown street lights to LEDs. However, developments such as Australian Keith Higgins' invention of a highly energy efficient LED street light suggest that LED street lights will become one of the main technologies in Australia within 5-10 years.
Some of the benefits of LEDs include: - Energy saving potential: LEDs can reduce energy consumption by 50-90%. This is because they require low power to operate.
- Long lifetime: LEDs can last up to 100,000 hours, significantly reducing labour and maintenance costs.
- Colour rendering: LEDs for street lighting applications have been designed to achieve a warm, white light that ranges from 85-90% on the colour rendering index (CRI).
- Small size: this provides flexibility in terms of retrofitting and packaging options.
- Optical control: LEDs produce directional light, meaning that it can light only the areas that need to be lit, minimizing light trespass.
- Operating characteristics: amongst other things, LEDs turn on and off instantly, and are dimmable.
For more information on the technical aspects of LEDs, see the Technology Assessment of Light Emitting Diodes (LED) for Street and Parking Lot Lighting Applications, prepared for the San Diego Regional Energy Office.
Trial: City of Whitehorse, Victoria, 2004–05
The Brentford Square project, undertaken as part of the Sustainable Public Lighting Initiative, involved an upgrade of existing car park lighting, combining both retrofitting and the installation of new, more efficient light fittings. Electronic ballasts and electronic photoelectric cells were added to nine existing 150 watt metal halide lights and 12 existing 400 watt metal halide lamps were replaced with 18 T5 lamps (2 X 24 watt). In addition, 15 LED marker lights (1 watt) were installed in the carpark at the end of existing aisles. This project was undertaken as part of Sustainability Victoria's Sustainable Public Lighting Initiative.
Trial: City of Charles Sturt, South Australia, 2003
In April 2003, the City of Charles Sturt installed 17 energy efficient DIO (diode emitting) lights in place of 80 W Mercury Vapour lamps at Station Place, Hindmarsh. The DIO lights are low voltage – 18V compared to the 240 V used by conventional lights. The results of the pilot study are summarised below (2006 figures).
Budget Allocation | $16,000 (plus $4,000 grant from the Australian Greenhouse Office) | Energy savings | 86.3% power reduction per year | Greenhouse savings | 10 tonnes CO2e per year | Financial savings | $1,495 per year in energy costs
| Payback Period | 10.7 years
| Other environmental benefits | The DIO lights contain no mercury
| Other economic benefits | The lamps are expected to last between 100,000 hours and one million hours, which means they may not need to be changed for 20 years. Ongoing decreased operational electricity and maintenance costs |
For more information, see the City of Charles Sturt's website.
City of Port Phillip, Victoria, 2001
In 2001, the City of Port Phillip replaced 290 mercury vapour (70 watt) lamps with DIO lights along its foreshore walking and cycling paths. This was expected to reduce the area’s public lighting energy consumption by 80%, extend light life and reduce light pollution. However the light trial failed because of the low light level produced, and Council have since removed the lights. For more information, see the City of Port Phillip's case study.
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In street lighting applications, several LEDs chips are attached to a coated printed circuit board and encased in a protective covering to suit the external environment. The LED fixture doesn't require a ballast or capacitor; instead, it converts the supply voltage to low voltage direct current, using a small electronic power supply.
At the moment, there is no commercially available LED luminaire suitable for use in street lighting. Existing LED luminaires are not compliant with the P4 sub-category for Pedestrian Area Street Lighting in AS1158, nor to AS3771 for Road Lighting Luminaires with Integral Control Gear. To achieve the lighting levels required for street lighting the LED arrays would need to be increased. This would increase its energy consumption, which would in most circumstances be similar to an equivalent traditional lamp source (e.g. 50 watt high pressure sodium lamp).
* For an overview of the suitability of LEDs for street lighting in Australia and New Zealand read 'LED lighting – saint or sinner for Australian and New Zealand street lighting' by Ironbark Sustainability.
* For a comparison between LEDs and T5s see the Q&A Service.
Large scale LED installation- Department of Defence
The Garden Island base in Western Australia has installed the first 330 of around 2200 lights to replace the existing street lighting. The lights are being supplied by Perth company Lightsense and aim to conserve energy and time and costs associated with the maintenance requirements of the current lighting. The Department of Defense is one of the largest users of energy of any Australian Government Department and the Garden Island base is one of the biggest bases in Australia.
Los Angeles- LED replacement
The Californian city will replace 140,000 of its streetlight fixtures with LED units over the next five years with help from the Clinton Climate Initiative in one of the most extensive municipal lighting retrofits in the USA.
The city's Bureau of Street Lighting will work with the initiative's Outdoor Lighting Program on the lighting system, which is expected to save the city $48 million in energy and maintenance costs and cut carbon emissions by 197,000 tonnes over a seven-year period. The cost savings accrued during that time will pay for a loan that will fund the project.
Case Study: LED street lights, City of Ann Arbor, Michigan, US
The City of Ann Arbor began testing two LED street lighting technologies in March 2007. The first is an LED globe fixture, which uses 50% less energy, and the second is a cobrahead fixture, which uses up to 80% less energy. The City believes that full implementation of LED streetlights could reduce Ann Arbor's CO2 emissions by over 2,200 tonnes, equivalent to 4% of the City's total emissions from municipal operations. In addition, this is expected to provide financial savings of around $100 per year per fixture.
For more information, see the case study presented at the C40 Large Cities Climate Summit, New York City, May 2007. This provides an excellent overview of Ann Arbor's public lighting situation, why LED street lights are being investigated, the expected environmental and financial benefits and the technologies being tested. See also their November 2007 announcement to changover all their lighting. You may also wish to consult Ann Arbor's website or contact Mike Bergren, Assistant Field Operations Manager, City of Ann Arbor on +1-734-994-4918.
Pilot Project: LED Technologies for Main Road Applications, Canada
Welland, Ontario has become the first city in Canada and North America to install LED lights in a roadway (i.e. main road) application. Other LED street lighting applications currently being piloted in Torraca, Italy and Ann Arbor, Michigan, USA, are testing only pedestrian (minor road) applications.
As part of the Welland pilot project, 47 Relume LED luminaires have been installed along a 2km strip of Fitch Street, Welland. The Relume luminaires use 90 watts, a significant gain on the 175 watts used by the high-pressure sodium lamps they have replaced. For more information, see:
LED streetlighting: the Light at Night Falls Bright
Welland receives kudos for energy efficiency
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LEDs are suitable for traffic signals and exit signs and have become the standard replacement for all new traffic signal installations in Victoria and other states. For more information see LED Information Sheet [PDF document] Size: 112 KB, Year: 2000.
Traffic signals, feature lighting and Help Phone lighting, VicRoads, Victoria, 2008
All new traffic signals and variable message signs that VicRoads is installing have energy efficient light emitting diode (LED) technology. VicRoads also has an ongoing program for retrofitting older traffic signals with LED technology.
In addition, in June 2008 VicRoads replaced old neon feature lights on Ophir St Pedestrian Bridge on the Western Ring Road with LED lights. These have proven to be more effective, save money, and are easier to maintain (as they are accessible from the side of bridge through a round UV rated clear tube and don't require lane closures to maintain). VicRoads are investigating using LED technology in all future feature lighting, for example in Deer Park Bypass Project, which originally proposed to use Metal Halide lights.
Finally, between February 2008 and May 2008 VicRoads commenced trials of LED lights on old Help Phone sites on the Western Ring Road. These have replaced old solar powered 12v lights which didn’t function correctly. Problems included maintenance issues, batteries not charging and 11w fluorescent globes failing due to environmental conditions not factored into their design. For more information contact Andrew Vedder, Senior Surveillance Manager at Electrical Operations, Metro North Region on andrew.vedder@roads.vic.gov.au or Ph + 64 (0)412 558 626.
Hobart City Council, Tasmania, 2006-07
LED systems are now being installed in all new traffic lights in Tasmania and will progressively replace the conventional systems used in older lights as they come up for replacement. This follows a trial of LED traffic lights for a year at a busy intersection in Hobart's CBD as well as at a number of pedestrian crossings. For more information, see ABC Tasmania's article.
Adelaide City Council, South Australia, 2000
Since trialing an LED traffic signals retrofit in June 2000, Adelaide City Council has retrofitted approximately a third of its intersections. The initial trial revealed that the LED traffic signals reduced outage rates by 80%, increased safety and decreased maintenance rates. A cost-sharing arrangement with the Australian Greenhouse Office, under its Emissions Reductions Incentives Program, enabled many of the retrofits to proceed. For more information, contact Adelaide City Council on (07) 8203 7209.
Case Study: Completing LED Traffic Signal Upgrades on a Tight Budget, Westchester County Department of Public Works, United States.
In 1998, Westchester County began converting the incandescent lamps in its traffic signals to LEDs. Since then more than 30 intersections have been retrofitted with red and green LEDs and converted 12 yellow flashers to LEDs.
Westchester County expects that the 502 LED signals installed during 2000 will cut electricity consumption by almost 183,000 kWh each year. As the county’s average electricity cost is $0.13 per kWh, annual energy cost savings could total more than $23,700.
In addition, the county has retrofitted 14 pedestrian signals – accounting for half of the county’s pedestrian signals – with bi-modal LED man-hand signals. Reference
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Solux
Tasmanian based company which supplies LED traffic lights directly to traffic authorities. Company director Mike Austin can be contacted via email or mobile: 0406121985.
Traffic Technologies is a major supplier of LED traffic signals in Australia.
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