Inspire : Public Works Nov Dec 2013
20 Public Works Professional November-December 2013 Driven by LEDS, this illumination revolution is already making its mark in forward- thinking early-adopter municipalities throughout the world. STREET LIGHTING Street and public domain lighting is poised for its biggest global transition since electric lighting replaced gas lamps in the 19th century. Driven by light-emitting diodes (LEDs), this illumination revolution is already making its mark in for ward-thinking early-adopter municipalities throughout the world, and LEDs are tipped to reach a global penetration of 64 per cent across new general lighting applications within seven years. Not only do LEDS offer energy savings of up to 70 per cent compared with conventional lamps, they also last 50,000 hours or more, which means they only need replacement about once every 12 years. Moreover, their lifespan can be extended for up to 100,000 hours when coupled with 'dimmable' (adaptive) smart controls. This is because the LED product's lifespan actually increases when the average current fowing through it is reduced. HOW THEY WORK The key to LEDs superiority is that they are illuminated solely by the movement of electrons in a semiconductor material. So, unlike incandescent bulbs, they don’t have a flament that will burn out, and don't get especially hot. Because of the way they produce light, LEDs offer many other benefts apart MAKING THE SWITCH Upgrading to LED lights can slash a council's electricity bill, as the City of Sydney has shown. As the cost of LEDs rapidly declines, the incentive to switch has grown nationwide. BY BRIAN MCCORMACK from their lifespan, energy saving potential and low maintenance. For instance, colour can be fnely controlled for architectural lighting, entertainment and other aesthetic applications by embedding elements in their semiconductors. In fact, the newer range of white LEDs is facilitating the illumination of public spaces with light that mimics daylight. In addition, LEDs offer high directionality, meaning they shine light only where it is needed. In the case of street lighting, this can prevent light from intr uding into residential windows or the night sky (see page 26). With lighting responsible for a ffth of global electricity use, and cities consuming 70 per cent of the world's energy supply, the potential savings from switching to more economical for ms of lighting are signifcant (about eight per cent of global demand). SYDNEY LIGHTS THE WAY In Australia, the City of Sydney is at the vanguard of the LED lighting revolution. In March 2012, it became the frst city in Australia to embark on a roll out of new energy effcient LED lights across its streets and parks. The lights are produced by GE and are being installed by UGL Limited. The $7 million, three-year project will see 6500 conventional lights (75 per cent of the city's lighting stock) replaced with LEDs. LEDs are well suited to artistic lighting, like these giant medallions above Llankelly Place in Sydney's Kings Cross. Originally installed in 2001, they were re- tted with LEDs earlier this year. When LEDs were trialled on Sydney's Martin Place, 90 per cent of survey respondents found them appealing and 75 per cent said they improved visibility.
Public Works Professional Sept - Oct 2013
Public Works Jan Feb 2014