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How smart is your street light?


The speed of light: Vivid 2015 showed the pace of innovation in creative lighting. In the practical space, GE is accelerating the deployment of intelligent lighting systems that use existing infrastructure for the greater civic good.Image Source: Vivid Sydney

As Sydney’s 2015 Vivid festival of light, music and ideas is committed to terabytes of photo and video memory, a new dawn of illumination is peeking over the urban horizon. In 2011 Australia was lit by a motley assortment of some 2.3 million streetlights, and the annual cost of public lighting was estimated at $250 million-half of that was the electricity cost, the other half, maintenance. In recent years those costs have undoubtedly increased, and so has our perception of public lighting as an area ready to switch …

When governments look at lighting bills that typically consume 30% to 40% of their power expenditure, they see potential savings—economic and environmental. When GE looks at lighting it sees underused infrastructure and a future in sensor-enabled fixtures, wirelessly linking light poles to the industrial internet, to make populated areas more functional and safer. Artists and architects have a vision of lighting as a potential source of revelation, attraction, even theatre.

“The most basic purpose of night lighting is to provide a safe and secure environment for people to be able to find their way around and to minimise crime,” says Helen Lochhead, New South Wales Assistant Government Architect. “But then the overlay to that is to actually help people enjoy and have greater use of public spaces, and to attract people, to extend the nighttime economy.”

True hue: Sydney’s ANZAC Bridge viewed from Pyrmont, before and after the City of Sydney switched to GE LED lighting

The entertaining spectacle of Vivid probably blinded visitors to a recent vast improvement in ambient lighting of Sydney’s streets after dark. Since 2012, the City of Sydney council has been working to bring about a financial, environmental and visual transformation of the city’s public areas. It is nearing completion of a $7 million project to replace all its mixed-up municipal illumination with GE light-emitting-diode (LED) lights—the first Australian city to make such an all-pervasive leap into the future.

Says Henry Eng, President and CEO of GE Light, Asia, “We are in the end phase of lighting the entire City of Sydney and the expectation that the city had for LED transformation has far exceeded its energy-savings requirement.”

As part of their commitment to reduce greenhouse gases by 70% compared to 2006 levels by 2030, the city council governors were looking to achieve a 40% reduction in the energy council expended on lighting. The GE lights, a combination of the GE LED R250 for roads, GE Duna for parklands and GE LED Modular Area Lights for public areas such as Circular Quay and Darling Harbour, have already delivered a 47% decrease in energy used, which translates to roughly $370,000 annual savings on power bills and a reduction in carbon dioxide emissions of almost 3,000 tonnes a year. An equal or greater financial savings in maintenance costs is anticipated due to the three times longer lifespan of LEDs compared to other light sources, and the fact that they have now been standardised—so a maintenance crew knows what kind of light they’re changing before they head out.

Before the LED transformation, says Lochhead, “When I was working for the City, they had so many different kinds of lights, every time there was something new on the market you would try it out. So literally the maintenance people would have to go out to a light that wasn’t working, get up in a cherry picker, look at the light, go back to the depot, find the right replacement and go back again. They had hundreds and hundreds of different lights and fittings.”

Now imagine that the new, standardised, LED network might also be sensor enabled and networked to allow the gathering of all kinds of information—localised weather conditions, air quality in city or industrial centres, seismic activity in earthquake-prone cities, traffic density, emergency situations, available parking spaces—and that they could be programmed to warn, direct or help people accordingly.

GE’s LED lighting has the potential to be supplied or easily upgraded with a sensor pack that feeds data to GE’s cloud-based Predix software platform for analysis. The company is trialling such systems in the US cities of San Diego and Jacksonville, and inviting programmers to develop applications for data analysis and response that will change how people manage their lives.

“One of the things we’ve realised,” says Eng, for example, “is that a lot of traffic in the cities is just circling around looking for parking. So having something with a sensing capability to identify where the open parking spots are will alleviate the traffic caused by people looking for parking spots.” Parking availability might be communicated by app to your smartphone, or perhaps to your GPS, giving you notice of the parking spot nearest you on the outskirts of an entertainment zone, or the rockstar park outside your destination.

“It’s the whole idea of using lighting as two-way communication,” says Lochhead. “It could be any number of things. It could be noise levels, pollution, a whole bunch of environmental metrics. You could communicate back to the population with a health alert: ‘This precinct has two zillion particulates per square metre.’ One of the aspects of good governance is giving people choices to make their own decisions. You can still go out in awful conditions or take risks by choice, but if you don’t have the information, you don’t have that choice.”

Accidents or emergencies could also be assessed or reported by video sensors. Is that triple-0 call a real emergency? What’s the most open route for emergency vehicles to take to the scene? Let’s raise the light levels to help the emergency crew, or to better judge the rising flood levels…

In the past, you’d turn the light on and have to wait five to 10 minutes for it to come up to light, and when you turned it off, you had to wait another 20 minutes for it to cool down

The adjustability of intelligent street lighting is a factor that will further decrease future municipal lighting bills and carbon emissions. In Britain many councils are turning street lights off late at night, in efforts to contain their costs, but intelligent lighting would respond to ambient light conditions, preventing over illumination at dawn or dusk. It could also dim as the traffic flow trickles to a halt late at night and rise in advance of approaching vehicles or pedestrians to light them safely on their way before dimming again. The nett result is savings while maintaining a high level of safety and navigability of urban and regional environments.

Networking, combined with LED lighting that can quickly dim or intensify illumination makes this responsiveness possible, in a way that previous lighting technologies were incapable of. “In the past, you’d turn the light on and have to wait five to 10 minutes for it to come up to light, and when you turned it off, you had to wait another 20 minutes for it to cool down before restarting. So even if you had the controls, you couldn’t turn the lights on and off because it wasn’t technically feasible,” says Eng.

The response of Sydneysiders to their new LED lighting system has delighted the council. In surveys conducted after the lights were trialled in Kings Cross, Martin Place, Circular Quay and Alexandria Park, 90% of people said they found the new lighting appealing, and 75% said it actually improved visibility.

LED fixtures are made up of a series of points of light or diodes, which can be more effectively directed to areas a council wants to illuminate, and they emit brighter, whiter light that renders skin colour, and the colours of buildings and objects more accurately. This allows drivers to more easily recognise hazards on roads, for example. Directionality also results in less unwanted spill of lighting into, say, suburban homes and upwards into the night sky—better for sleeping, stellar for star gazing.

“LEDs are so superior in terms of brightness and colour,” says Lochhead. “People don’t look grey or green. We used to like sodium lighting, with its yellow light, for lighting sandstone buildings, but if you used it to light a tree, it went a browny-grey colour—parks looked terrible with that kind of lighting. Similarly mercury-vapour and metal-halide lighting, which were the next generation, they change colour as they deteriorate, so you might see a row of streetlights and they’re all different colours because the actual light bulbs are different ages. LED is much more stable and consistent.”

“At the beginning of my career,” she adds, “the cost of lighting and the amount of lighting you had to use to get effects with buildings and spaces was completely different. It’s game changing what you can do now with LED. And you can program lighting, so you can have it on more on particular occasions. Also, you don’t have to have the same solution for every location. It can be so much more nuanced.”

Recent theatrical applications of even the old forms of lighting included curating views of historical Sydney by highlighting, say, the historical buildings, staircases and sandstone work of The Rocks precinct, while more modern buildings remained less brightly lit. “It gave you this sort of edited view of the city,” says Lochhead. With programmed LED lighting, such selective, dramatic lighting of the city might be applied at will, at much lower cost than previously possible. “It could let you celebrate those architectural or artistic moments that take your breath away; make you go, ‘Oooh, I never saw that before.’”

Dollar savings, improved safety, advanced traffic control, informed choices and reduced CO2 emissions—networked LED lighting will enable councils to more responsibly manage their realms. But Vivid reminds us that lighting is also for pleasure and enhanced enjoyment of the night. A city that looks and feels inviting after dark extends an invitation to its citizens every time the sun goes down.

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