Winner | Asian Digital Media Awards 2020

Liveable Cities Series: Illuminating the path to sustainable lighting

Come March this year, residents in Singapore will be treated to a dazzling display of lights that will brighten the Marina Bay waterfront and send a message that cities need better, more sustainable outdoor lighting.

This artistic display is part of Asia’s first and only sustainable light festival, iLight, whose architects are government agency, the Urban Redevelopment Authority, and SmartLight Singapore, a non-profit group that was set up in 2010 to raise awareness for improved outdoor lighting design and energy efficiency.

In its second year, iLight will feature 30 light art installations spread throughout the Marina Bay waterfront, which will be free for the public. The teams of artists that created the installations used locally sourced materials and energy efficient technology such as LED lights to produce interactive exhibits on ahuman scale.

One such installation, an exhibit called FLOW by Singaporean designer Olivia Lee, has LED panels powered by vertical axis wind turbines. Viewers are engaged to turn the turbines manually to produce light in periods of low wind, thus reinforcing the themes of interactivity and sustainability.

iLight curator and SmartLight founder Mary-Anne Kyriakou, who unveiled the first 10 artists chosen for the festival in December, told Eco-Businessin an interview that the festival would help raise awareness among the public and businesses of the need for sustainability in outdoor lighting.

Such lighting, in the form of street lights, traffic lights, external lights on buildings and outdoor advertising - typically used by cities and businesses to provide safety and shape the night-time landscape - is integral to every cityscape.

“At night, we are governed by vision; we are dependent on artificial light,” explainedMs Kyriakou.

Now with a growing global awareness of the need to reduce both energy consumption and carbon dioxide (CO2) emissions, municipal lighting – or lighting that falls under the management of local governments - is increasingly under scrutiny.

Using data from the United Nations, the United States-based non-profit Clinton Climate Initiative estimates that, globally, public lighting consumes 159 million megawatt hours (MWh) of electricity per year andemits nearly 81 million tonnes of CO2 emissions in the process.

But while the impact of outdoor lighting on a city’s CO2 emissions is significant, so are the opportunities for reducing them through large-scale retrofit projects and new technologies.

These readily-available opportunities have driven the Clinton Climate Initiative (CCI), launched in 2006 by former US President Bill Clinton, tofocus on outdoor lighting as one of its six programmes designed to most effectively help cities meet their CO2 emissions targets. It combines the efforts of government and businesses to seek out practical solutions to the climate issues surrounding cities, forests and clean energy.

CCI’s global network of city leaders, called C40 after the original 40 cities that signed up for the programme, work together to find fast, effective ways of reducing the world’s urban climate change impact.

CCI’s outdoor lighting programme director, Emma Berndt, noted in a recent statement that crunching the numbers for proposed outdoor lighting projects demonstrated a compelling case for action, and that mayors in the 15 cities involved in the programme were making the issue a priority.

“This is good news,” she said, adding that recent innovations in lighting technology have made it possible for cities to maintain or improve the performance of their street lighting systems, while significantly reducing energy and maintenance costs.

While up-front investment costs remain a challenge for cities, said Ms Berndt, street lights deserve renewed focus and attention as cities work to reduce greenhouse gas emissions and save energy and money.

In a white paper released in 2010, researchers at CCI claimed that the world could reduce electricity demand for public lighting by 80 million MWh and avoid the emission of over 40 million tonnes of CO2 annually by using existing energy efficient technology.

The potential for emissions reduction through more efficient street lighting is large. In Australia for instance, 37 per cent of Sydney’s municipal emissions are from street lighting and in Melbourne, the percentage is over 53, according to CCI research.

Economies of scale

The paper’s authors state that cities are in a good position to take advantage of the economies of scale of large retro-fit projects,which are far more economical than replacing streetlights a few at a time.

“Many cities own and operate their street lighting systems and therefore can act directly and swiftly to implement a retrofit program that reduces emissions and utility bills,” notes the report.

The city of Los Angeles is trying to do just that with a US$57 million project that involves replacing 140,000 of its 209,000 street lights with light-emitting diode (LED) fixtures. Working with CCI and the mayor’s office, the Bureau of Street Lighting expects to reduce its electricity consumption by over 50 per cent and to benefit from lower maintenance costs and better light quality as well. As of 2010, the project was by far the largest LED street lighting initiative in the world.

LED lighting has emerged as the dominant new technology for outdoor lighting. First developed by the US National Aeronautic and Space Agency (NASA) in 1962, the technology has only recently become practical and affordable for use as outdoor lighting.

Compared to high-pressure sodium (HPS) lighting, the technologymost widely used for today’s street lighting, LED uses half the energy, lasts longer and emits a broader light spectrum – resulting in a white light that is often described as more appealing and better for visibility than the pinkish orange light produced by HPS lamps.

Light from HPS lamps results from vapour given off when sodium is excited by electricity, while in an LED bulb the light results from passing electricity over a specialised electronics device.

Yet, while LED looks good on paper, experts warn that cities should do their homework before making the switch.

The industry faces a number of challenges, including inconsistent quality from different providers, rapid changes in the technology that make it difficult to plan for a long-term investment and existing street lighting standards that are inappropriate for the technology.

Another challenge is the high upfront cost, which can take from seven to 10 years for buyers to recoup.

Professor Mark Rea of the Lighting Research Centre in Troy, New York in the United States told Eco-Business that while the trend is definitely moving toward LED technology, inertia due to the massive scale of established lighting systemswill prevent a complete transformation for the foreseeable future.

HPS lamps, which are proven to be reliable and more energy efficient than their predecessors, are still a good source for the communities that have already invested in the infrastructure, he added.

LED fixtures are expected to last for more than 50,000 hours of operations, compared to 20,000 to 24,000 hours for HPS lamps. In theory, this translates to lower replacement costs and lower costs for maintenance and operation.

But, as Professor Rea notes, investment in LED street lighting can be risky for several reasons.

The lack of history and experience with the technology can make it difficult to predict how well LED street lights will work in different areas. LED lighting performs differently in hot and cold temperatures whereas the performance of sodium-based technologies does not vary with the climate.

Professor Rea found through his research on pilot projects in North America that cities tend to install LED fixtures on the same poles as the replaced fixtures – a move that often results in inappropriate spacing and heights for the LED lights.

In many cases, the demonstration projects violated municipal lighting standards for road safetyin terms of light output.He noted that these violations do not necessarily mean that the roads were unsafe, but rather that the standards were designed for a different type of light that does not have LED’s broader light spectrum.

To complicate matters further, not all providers produce the same quality fixtures, and instances of faulty or substandard equipment have caused potential customers to hesitate. The CCI paper on outdoor lighting noted that experts describe a wide range in lighting effectiveness from LED technology that reflected a lack of consistency in LED product quality across manufacturers.

The situation is hampered by insufficient warranties, added Professor Rea. Investors calculate the overall life-cycle costs for LED fixtures, which include the cost of energy consumption and maintenance, based on a life span of up to 20 years. Yet, the typical warranty is only two to five years.

LED ideal for green field cities in Asia

While these barriers may deter some communities from replacing existing lighting, they will be less of a factor for cities installing new systems – a situation more common in developing Asia than in North America – provided they do their research.

“If you are starting with a clean slate, rather than retrofitting an existing system, LED is a good source,” said Professor Rea.

For the moment, LED technology costs are higher over the course of their life cycle compared to other technologies in use. Within the next year or so, however, Professor Rea expects that to change.

Technological improvements combined with greater production volumes are contributing to a projected annual decline in prices of 5 to 15 per cent, according to CCI.

As the use of LED technology becomes more accepted for street lighting, more and more communities around the world are test-bedding the technologies and developing their own standards.

Last November,Taiwan’s government announced it would spend over US$23 million to replace 53,000 fluorescent street lamps with LED fixtures made by local manufacturers. To facilitate the project, as well as the growth of its domestic LED industry, the government’s Bureau of Standards, Metrology and Inspection is developing new standards for LED streetlights that will be ready next year.

Not to be left behind, some industry associations such as the Illuminating Engineering Society of North America (IESNA) and the International Commission on Illumination are also adapting their standards for the design of outdoor lighting systems.

Solar street lights sprout across Asia

Meanwhile, the energy efficiency of LED street lights continues to rise with new projects – some of them powered by renewable energy.

In July, the state of Haryana in India announced plans to install LED street lamps with solar photo-voltaic cells in the city of Gurgaon. After identifying local manufacturers for the project, Haryana officials plan to extend the project to 14 other districts.

At a recent high-profile UN event in Durban in December, a new Bill and Melinda Gates Foundation-backed initiative called ‘Momentum for Change’ featured an innovative solar LED street light project in Guiyang, located in the southwest China.

Attended by South African President Zuma, UN Secretary-General Ban Ki Moon, and UN climate chief Christiana Figueres, the event highlighted ten ‘Lighthouse’ projects that demonstrated how public-private partnerships could effectively promote the expansion of clean technology into developing countries.

One of those projects was the Guiyang LED street lighting project, which is part of the 1,000 Villages Programme, an undertaking launched in 2009 by non-profit organisation The Climate Group and the Jet Li-founded One Foundation Project to provide solar-powered LED street lighting to communities in developing countries with insufficient access to electrical grids.

The goal of the five-year 1,000 Villages Programme is to set up solar-powered LED lighting demonstrations in 400 villages in China within the first phase, after which the project will be expanded to a further 600 villages in China, India and Africa.

Programme leaders for the Guiyang project worked with 13 villages to provide training and technical assistance to local communities and to install an initial 100 solar-power LED lamps donated by Philips Lighting.

Using data collected and lessons learnt from this and other 1,000 Villages Programme demonstration projects, The Climate Group and its partners are developing policy recommendations and effective financial models to enable more widespread use of the technology in developing countries.

The Climate Group’s director for Greater China, Changhua Wu, told Eco-Business  that lighting projects such as these served multiple purposes. The initiative would spur green growth, save energy and combat climate change in poor rural areas, while improving the quality of life people in local communities, she added.

For communities with limited access to electricity, the addition of solar-powered streetlights can have a significant impact on the living habits.

“The solar lighting extends the day after sun set at affordable cost, increasing the level of safety on roads and streets and allowing for more economic and social activity after dusk,” said Ms Wu.

But the benefits are not limited to remote communities. Ms Wu also said that sun-rich cities around the equator, many of which are struggling to meet steep increases in energy demand, can use the technology to ease the strain on their electricity grids.

The Climate Group chief executive Mark Kenber noted in a statement after the UN event that “the massive upscale of smart technologies and clean energy can and must benefit all the citizens of the world, from rural communities in China to the inhabitants of every big metropolis.”

The power of technology

Apart from LED technology, some other types of lighting have emerged as alternatives, such as induction lighting, which has a 40 per cent energy savings over HPS lamps and an impressive theoretical lifespan of 100,000 hours.Some others, such as plasma lighting and new versions of metal halide lighting, have shown potential but have not yet matched LED lighting for commercial viability.

One of the most crucial technologies needed to improve the efficiency of outdoor lighting is not even lighting; but rather automated systems to manage lighting levels. Such systems allow cities to have lights on only when and where they are needed, and also indicate when maintenance is required.

As much as the lighting technology itself, the management and design of lighting according to the needs of cities will determine the sustainability of urban lighting.

According to CCI, many cities use excessive lighting for roads and sidewalks because they want to improve safety and visibility, but ongoing research into the effects of lighting on traffic accident rates show that not all light is created equal.

Researchers have known for some time that roadway lighting at intersections reduces traffic accidents - one University of Michigan Transportation Research Institute study found that good street lighting reduces pedestrian crashes by half – but only recently have experts determined that broad-spectrum lighting enhances night-time vision more than traditional street lights.

With the white light emitted by LED and other broad spectrum light sources, cities can use lower light levels to achieve the same visibility. By adjusting for this fact, cities can save energy and money.

While a number of communities have increased lighting in public areas to reduce crime, no conclusive research has proven this to be the case, notes LRC’s Professor Rea. However, one standard within the industry describes safe pedestrian zones as those in which the facial expressions and movements of passersby can be recognised from a distance.

By better understanding what kind and how much lighting makes urban areas safe and comfortable, cities avoid the excessive use of light that leads to wasted energy and light pollution.

Dark sky unfriendly

Light pollution is defined as light that spills over into areas where it is not wanted, light that creates an intrusive glare that negatively affects people and wildlife, or the accumulated light that casts a glow over a city and reduces the darkness of the sky.

An international “dark sky”movement began in the 1980s with astronomers who noticed that conditions for viewing stars were degrading due to light pollution. Since that time, a global campaign spanning over 70 countries has emerged to promote better management of lighting and reduce the light pollution that, these days, goes hand in hand with developed cities.

The movement has had some measure of success - many cities have passed legislation limiting the placement of outdoor, lit advertising. City agenciesare also selecting lighting fixtures with a feature known as full cut-off, meaning they produce a minimal amount of light pollution by only sending light in the desired direction. The industry describes this type of feature as ‘Dark Sky Friendly’.

Light pollution is a problem not only from an environmental standpoint, but also from an aesthetic point of view.

SmartLight Singapore’s Ms Kyriakou said cities that are overlit, such as Shanghai, Hong Kong and New York, are beginning to resemble each otherand lose their distinctiveness.

Singapore’s iLight Festival aims to show that quality over quantity is the key to unique cities with sustainable outdoor lighting. Image: SmartLight Singapore

Done well, outdoor lighting in public spaces and on buildings can create a distinctive identity for a city, but it is imperative to find the balance between revitalisation and too much light, she noted.

Underlit areas are dead spaces, and outdoor lighting can bring new spirit to a place. But too much lighting is uncomfortable for people, said Ms Kyriakou.

In her experience, lighting designers are moving away from the glaring lights shined on buildings and public spaces in favour of detailed lighting designs that encourage public enjoyment of the night-time landscape.

In the case of the iLight Festival site of Marina Bay, a newly developed park space frequented by tourists and professionals from nearby office towers, the lighting festival is expected to transform the area into a family-friendly night-time public destination.

“The festival draws people into a part of the city generally perceived of as unaffordable to enjoy the night-time built environment. It creates magic and wonder,” she said.

By encouraging the region’s lighting designers, who collectively submitted about 100 proposals to the upcoming festival, to focus on reducing their carbon footprint and creating dark sky friendly installations, the iLight festival is raising the bar for the region’s urban lighting projects.

Ms Kyriakou said it is her way of raising awareness of the need for quality over quantity in urban lighting, and of its effect on the urban lifestyle.

“Asia’s cities are quite vibrant.  You cannot change the (hectic pace of a city) with well-designed, sustainable lighting, but you can change the quality,” she said.

Thanks for reading to the end of this story!

We would be grateful if you would consider joining as a member of The EB Circle. This helps to keep our stories and resources free for all, and it also supports independent journalism dedicated to sustainable development. For a small donation of S$60 a year, your help would make such a big difference.

Find out more and join The EB Circle

blog comments powered by Disqus

Most popular

View all news

Industry Spotlight

View all

Feature Series

View all
Asia Pacific's Hub For Collaboration On Sustainable Development
An Eco-Business initiative
The SDG Co