July 2010 – FAVOURITES: Lighting is far more complex than meets the eye. Greater efficiency might come with dangerous levels of mercury, or metals that need to be disposed of, reports Lynne Blundell.
Lighting is hot right now. Every week, it seems, there is a new claim about the energy efficiency of this product or that. And with lighting consuming 19 per cent of the world’s electricity generation and CO2 emissions from lighting equivalent to 70 per cent of global emissions from passenger vehicles, according to industry data, it’s hardly surprising. But just how real are all these claims and is there enough emphasis by Green Star and other ratings tools on sustainable practices in the manufacturing and disposal of lighting products?
It is certainly true that advances in lighting technology over the past decade have been enormous – incandescent bulbs, the main source of lighting since the beginning of the 20th century, are being phased out and replaced by alternatives such as compact fluorescent bulbs. Halogen downlights, all the rage in the 90s, are also being replaced with more efficient bulbs such as LEDs (light emitting diodes) and metal halides.
In commercial buildings linear fluorescent tubes have gone ahead in leaps and bounds, T8s being replaced by the more efficient T5s (although one Australian manufacturer is bucking this trend with development of a highly efficient version of the T8 – see our story on this). And LEDs are becoming increasingly sophisticated and are now widely used for feature lighting, on facades and in all sorts of outdoor applications.
But according to engineers and designers who spoke to The Fifth Estate, while exciting developments are happening, there are also a lot of exaggerated claims. And for every advance in energy efficiency there are other problems to deal with such as high embodied energy and recycling and disposal problems. It is an industry in transition.
Take compact fluorescents globes for example – they are much more efficient than the incandescent globe but they also contain mercury and disposal of this is a major safety and environmental issue. In Europe and the US regulation of the disposal and handling of electronic waste has been significantly tightened in the last few years but in Australia regulations are far from strict and vary from state to state, the onus often placed on local councils to provide solutions. Too often they end up in landfills.
Then there are LEDs, also very efficient, but the amount of heat they throw off requires a large metal heat sink on the back, making their cradle to grave footprint pretty large – and once again disposal is an issue.
According to Ibby Kanalas, senior electrical engineer associate with JHA Consulting Engineers, there really isn’t anything yet that matches the linear fluorescent tubes for general office lighting in terms of efficiency, light quality and payback period.
“Large scale LED solutions don’t stack up yet compared to fluorescent if you do a comparison on a cost benefit and payback period. You need to use a higher wattage per square metre of LEDs to achieve the same lighting levels as T5s and if you are going for Green Star points this can make a big difference,” says Kanalas.
With each LED light fitting costing a substantial amount, payback period is currently more than 20 years, which is just not viable for tenants who are on a three to five year lease.
There are six points available under Green Star and the specification for efficiency is 5 Watts per sq m or less. This is very easy to achieve with T5s but not LEDs, says Kanalas. And even when you take into account LEDs’ long lamp life they don’t measure up on a cost benefit basis.
“T5s have a lamp life of around 20,000 hours while LEDs are guaranteed for 50,000 hours so they have two and a half times more life. But the fitting costs four to five times as much. LEDs also generate a lot of heat so if this isn’t taken away effectively it will reduce the lamp life. Some manufacturers are guaranteeing five years just to sell them which is a good commercial approach,” says Kanalas.
But it is the disposal and manufacturing processes of both lighting technologies that Kanalas would like to see under the spotlight. With fluorescents the main issue is mercury, while with LEDs it the large amount of metal needed to draw away the heat. Unlike other building products there are no stipulations regarding manufacturing processes for lighting under Green Star assessment.
“Lighting needs to be looked at in a more holistic way. LEDs, for example have changed a lot in the last two to three years – the light output has gone from 10 lumens per watt to 40 lumens per watt and it is going to go higher. But the heat also increases as it gets brighter and so the metal heat sink gets larger as well. Is this really green? All the energy saved in the higher efficiency is taken up in the manufacturing process and disposal,” says Kanalas.
Energy efficiency is not the only issue
Rebecca Patterson, electrical engineer and Associate with Umow Lai, agrees that efficiency is only one of the issues to consider when choosing lighting. Another significant one is quality of light – it is not particularly useful being energy efficient, she says, if the space ends up looking like a bat cave.
The trick, says Patterson, is to get the best “bang for your buck” from lights while still achieving effective and attractive lighting. Often a combination is needed – T5s for general lighting, LEDs for feature panels and halogen desk lamps for individual control. Umow Lai used minimal overhead lighting with individual halogen desk lamps in Grocon’s Pixel building to give individual control and reduce over-lit spaces. The days of throwing in hundreds of halogen downlights are certainly gone but Patterson would not like to see regulation go so far that lighting becomes grim.
Each technology has its drawbacks – T5s, while the most effective overall lights for offices, throw light downwards so tend to make the ceiling and walls grey. And LEDs, while good at colour are not so effective at achieving white light and are very directional and somewhat cold, says Patterson.
“In Europe there is more of a trend to getting more light on the walls and ceilings rather than just using lights like T5s to throw light downwards. Sometimes there are no general lights in office spaces but just individual lighting on desks. I think we’ll be heading more down that path here, towards basic lighting and away from overlit spaces, particularly in the premium buildings.”
Other features increasingly used in commercial buildings include lighting controls such as motion sensors to activate lights when people are in the building and daylight harvesting where lights adjust to the amount of sunlight coming in to a building.
Government should provide recycling facilities
And with the increasing use of fluorescent lighting Patterson expects to see more pressure on government to provide recycling facilities for old fittings.
“The cheapest ones still have quite a lot of mercury in them. As they are made more efficient there is less mercury but I expect people are going to start making more of a fuss about recycling and putting pressure for less mercury to be used.”
Steensen Varming’s lighting engineer Mirjam Roos says lighting controls are sometimes overlooked in energy saving strategies. She would like to see a focus shift from light sources to a more holistic approach that also addresses how these sources are controlled.
“Quite simply, the best way to save the energy is to switch the lights off when not needed,” says Roos.
“For example, in a large government development we are working on in Brisbane, nearly all lighting within the project, from general lighting down to individual workstation task lighting, is operated via motion sensors or timers that turn lighting off when not needed.”
And while saving energy is important, the impact of lighting on peoples’ comfort and wellbeing needs to be considered. There is no reason why lighting cannot be both aesthetic and energy efficient, says Roos, citing Steenson Varming’s lighting design for the Sydney Opera House box office and concourse, which uses half the energy of the previous lighting, The company also did the lighting design for the National Portrait Gallery in Canberra, using a system of high colour rendering linear fluorescent lamps in the galleries.
“It is the first major gallery in Australia to use a linear fluorescent system for display lighting,” says Roos. “The wallwashers create even display lighting, enhance the geometry of the space and contribute to the outstanding energy performance of the building.”
Data released from the International Association of Museum Facility) position the Gallery well ahead of other Australian facilities with its annual electricity consumption half of the mean average of all sites.
“Even if there are other, sometimes greater contributors to energy consumption, lighting is a more visible element of building services and therefore many times the primary target when it comes to energy strategies. This happens sometimes at the expense of reduction in the quality of visual environment, which is not always beneficial for the occupants’ wellbeing.”
Take the recent “phase out of incandescent bulbs” for instance, says Roos. When the lamps were phased out there was no direct replacement available with the same quality of light and there still isn’t.
“Yes, these lamps have less light output for unit power, however replacement options such as the compact fluorescent lamps have other issues such as mercury content, high embedded energy going into manufacturing process, compatibility with existing light fittings and disposal,” she says.
LEDs will dominate
On the other hand, LED technology is evolving fast but there is still a big lack of knowledge in the market when it comes to assessing LED products. Price is also an issue.
“Looking at the pace of the development in LED technology and the funds invested in LED product development, I believe in a few years this technology will dominate the lighting market, and will open the doors for new, exciting opportunities in lighting design.”
If prices of LEDs come down by as much as some in the industry are predicting (70 per cent by 2015) there is no doubt LEDs will have much higher market penetration in the near future. According to a report by climate change consultants, Carbonetrix, if prices do come down by that amount and energy use can be then halved by using LED tubes while providing similar illumination, the payback period will be around three years for a typical office, or lower once maintenance costs savings from longer lamp life are considered.
One recently patented Australian LED product is promising big energy savings, reducing power consumption by 68 per cent when installed in the Gosford City Council’s car park, where it replaced the fluorescent lighting.
The product’s manufacturer, enLighten, began taking its product to the market in November 2009 after almost two years of research, several patent applications and one patent granted and certified. Since then the company has conducted several trials in a mixture of office and car park environments. Both Gosford City Council and Willoughby Council have replaced fluorescent tubes with the LED product.
Organic glow – More choices for energy-saving lighting
22 September – From The Economist – WITH many countries phasing out the use of traditional incandescent light bulbs to save energy, the lighting business has taken on a new dimension and is now offering a broader range of products than the one perfected in 1879 by Thomas Edison. There are compact fluorescent lights (CFLs), light-emitting diodes (LEDs) and some firms are developing quantum dots, which are lights made from tiny crystals of semiconducting material. Now another new source of lighting, organic light-emitting diodes (OLEDs), is starting to take the spotlight.
Philips, which is based in the Netherlands, has produced a strip of lighting made from OLEDs that can be powered directly from a mains electricity supply. That may not seem to be a brilliant invention, but in the lighting business it is a breakthrough. Although still at the laboratory stage, it will eventually mean that bulky power electronics and transformers will no longer have to be used with OLED lights, which brings down costs, simplifies design and allows them to be fitted into more products. In recent years the emergence of mains-powered CFLs and LEDs has started to turn them into direct plug-in replacements for incandescent bulbs. OLEDs, however, will fulfil a different role.
Compared to an incandescent bulb, which might cost only about 50 cents and burn for 1,000 hours, CFLs cost around $3—although they use up to 75% less power and last much longer. LED lights cost a lot more, but they are even more efficient. Osram, which is part of Germany’s Siemens, recently launched the Parathom Classic, a LED lamp shaped like conventional 60 Watt light bulb. It uses 90% less power than an old-type bulb and has an average life of 25,000 hours. It has gone on sale in Europe for around €50 ($64).
The quality of light from these new bulbs is different. Some people prefer the warmer glow of an incandescent bulb to the light produced by CFLs. Nor do they like the time it takes for these bulbs to reach their maximum illumination. Unlike an incandescent bulb, which uses electricity to heat up a wire filament sitting in a low pressure inert gas encased in glass, a CFL uses electricity to excite mercury vapour, which produces an ultraviolet light that causes a phosphor coating on the inside of the bulb to glow. Disposing of the mercury once these bulbs wear out causes some environmental concern.