Metal halide

: Metal Halides in Bourke St Mall, on the Melbourne Sustainable Public Lighting field trip at the ICLEI Oceania ACCELERATING NOW! Conference May 2007

Metal halide lamps have better performance than mercury vapour lamps, excellent colour rendition and efficiently convert energy to light.

Metal halide lamps operate most reliably with an electronic ballast, which delivers a constant voltage to the lamp regardless of whether the supply is over or under voltage. An iron core ballast, on the other hand, may amplify voltage increases/drops. Osram, an Australian supplier of ballasts, claims that the use of an electronic ballast will extend the life of a 9000 hour metal halide lamp to 14,000 hours.

One electronic ballast currently on the market is the Active Reactor. Using Active Reactors in combination with metal halide lamps reduces the energy consumed by a standard metal halide fitting by about 17.5% over its lifetime. Although Active Reactor units are currently quite expensive, using Active Reactors will reduce lamp changeover costs, as they extend the lamp life of a standard metal halide by about a third.

When metal halide lamps first appeared on the market, they were susceptible to failure and needed sensitive handling. Their high cost and short life span meant that they were not economically viable for most public lighting applications, though they were still sometimes installed in high prestige areas to enhance the night time appearance of the area.

More recently these issues have been either resolved or improved and metal halides are now the most commonly used lighting for sports and floodlighting applications. Metal halides can be used to provide a similar performance to high pressure sodium, albeit with a reduced lamp life and a blue, white colour instead of the yellow of the sodiums. As a result many Councils now use Metal Halide lighting for premier sites in shopping strips and around civic buildings. Sodiums are currently used more widely in major road lighting mainly due to their long lamp life.

Since metal halide is a fairly new technology, it is likely that it will continue to improve in reliability, life and performance. Its emerging compatibility with high pressure sodium gear is a positive development that will enhance its application as the economies of its use improve.

Snapshot of metal halide technology

: Click to enlarge

Trials and demonstration projects

Note: the 2004–05 Victorian trials and demonstration projects mentioned below were undertaken as part of the 2004 Sustainable Public Lighting Initiative funded by the former Sustainable Energy Authority Victoria (SEAV).

City of Adelaide, South Australia, 2007
The City of Adelaide is currently converting all of its streetlighting to metal halide because of its energy efficiency and community safety benefits.

Town of Mosman Park, City of Subiaco and City of Swan in conjunction with WALGA, Government of Western Australia and Sage Consulting Engineers, Western Australia, 2004–06
This project involved the monitoring of new street lighting installations in Midvale, Mosman Park and Subiaco, beginning in 2005. Three lamp technologies were tested in the trial: fluorescent, metal halide and high pressure sodium.

For more information, see the Sustainable Energy Development Office's article or view the final report, Improved Streetlighting Study for Greenhouse and Safety Benefits - Institutional and Technical Review. This trial was also used as a case study by the Australian Greenhouse Office (AGO).

EnergyAustralia, Marrickville Council and the Street Lighting Improvement Program, New South Wales, 2005
Seventeen luminaires on Enmore Road Newtown containing 250W mercury vapour lamps were replaced in February 2005 with 250W metal halide retrofit lamps. To February 2006, no identified failures or other technical issues had been reported and EnergyAustralia crews did not report any difficulties with the installation. For more information about this trial, please see the case study available from the AGO.

City of Port Phillip, Victoria, 2004–05
The City of Port Phillip developed and implemented an energy efficient street lighting design which combined 25 metal halide lamps with the use of electronic ballast technology or/and sensory systems that detect lamp failure along Acland Street between Fitzroy and Carlisle Streets.

This demonstration project, in a highly visible and visited location, was designed to help determine future sustainable street lighting strategies for other municipalities. The City of Port Phillip monitored and documented the OMR costs of the lamps during the project. View Map

City of Melbourne, Victoria, 2004–05
The Sandridge Bridge trial involved the installation of 40 catenary lights (20 watt metal halide) and 25 T5 flourescents (28 watt). Sandridge Bridge was selected as the location for this trial after heritage issues prevented it from going ahead at its original location in the Fitzroy gardens. View Map

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. View Map

Melton Shire and Stockford Development, Victoria, 2004–05
The Parks of Bellevue Hill in Hillside is a 351 lot residential subdivision. 14 metal halide induction lamps (55 watt) were installed as a demonstration project. View Map

Salisbury City Council, South Australia
Salisbury City Council is conducting a 2.5 year trial involving four energy efficient streetlights: 32W compact fluorescent, 35W metal halide, 70 metal halide and 70 watt high pressure sodium. Council will monitor and compare their running costs, efficiency, light output and residents’ satisfaction. The lights will analysed for their ability to replace existing 80W Mercury Vapour lights, or even the 50W high pressure sodiums (which are becoming a less attractive option because of colour and spacing issues).

So far (13 May 2008) no readings have been taken yet, but there has been one resident comments about the CFLs. This trial follows an earlier trial by Council in 2002 that tested the 50 watt high pressure sodium. The cost of the trial has been minimised for council as the company supplying the technologies is also conducting its own research into the lights. For more information, contact Salisbury City Council Traffic Engineering Officer, Ken Potter, on (08) 8406 8281.

Suppliers

OSRAM supplies electronic ballasts for metal halide lamps.

Philips

Most lamp suppliers can supply Metal Halide

The Sustainable Public Lighting website was created by ICLEI Oceania. Funding for this website was provided by the Australian Greenhouse Office (AGO) in the Department of Environment and Water Resources. The site is based on Sustainability Victoria's Energy Toolbox website.