The growth of LED lighting and its technology in recent times has been exponential, and although research and development is expected to plateau in a few years’ time, we are currently experiencing the LED boom period.
LED – before today
One of the key milestones in LED’s evolution was the invention of a high brightness GaN LED by Shuji Nakamura, whilst working for the Japanese LED giant, Nichia, in 1993. The brilliant blue light produced by the GaN LED could be converted to white light with a yellow phosphor coating—a discovery that allowed white LEDs to go into production soon after.
When white LEDs first became available their typical luminous efficiency was a modest 5 lm/W (lumens per watt), which even compares unfavourably with the usual 10-20 lm/W of an incandescent lamp. However, we’ve come a long way since the advent of white LED. According to American LED manufacturers, Cree, 2009 marked the beginning of the LED revolution. Back then a warm white LED lamp had a typical efficacy of 27-54 lm/W (stats collated by the by U.S. Department of Energy). By 2012 this had risen to 70-100 lm/W, which is more or less where we are now.
The achievements of lighting R&D labs in the past few years have provided a glimpse into what might be possible in the not-so-distant future. In early 2010, Cree broke the 200 lm/W LED efficiency barrier with a 208 lm/W measurement under lab conditions (in layman’s terms this is raw LED chip performance before it is wrapped up in LED lamps, and fittings). In 2011 Cree were at it again with a new 231 lm/W record, whilst competitors Osram claimed an impressive 142 lm/W lab record for a warm white light source (efficiency normally being greater in cool white LED light sources). The company that essentially started it all, Nichia, have also been making ground-breaking research and development progress in improving LED output and efficiency.
Other challenges in LED development have been in areas such as reduced production costs, more stringent quality control and better colour accuracy. Two or three years back Havells-Sylvania conducted a survey that found 85% of consumers to be unhappy with the quality of LED lights, which was something of a shock to the lighting industry. For all its sins, incandescent light has an inherently high quality light output, so that’s an area where LED R&D is strongly concentrated. In early 2013 Cree introduced a range of LED downlights that combined an impressive 90 lm/W efficacy with a high CRI (Colour Rendering Index) in excess of 90.
The fruits of many years’ hard work are beginning to ripen …
LED light bulbs
The inherent properties of LED make it well suited to many applications and various types of lamp:
A retro-fitting GU10 mains powered reflector bulb is well served by LED technology, especially since CFL equivalents tend to be too large for existing fittings and notoriously do not provide instant light unlike LED. Of course there are the usual benefits over a halogen equivalent, including a lifespan up to 25 times longer, minimal heat output, and a massive energy-saving advantage. The directional nature of LED makes it a natural choice for a spotlight too, whereas an incandescent source relies heavily on the classic reflector design for a concentrated beam of light. Lyco recommends the Sylvania 5.5W LED GU10 Spotlight as a worthy replacement for a 50W halogen equivalent!
A GLS (General Lighting Service) bulb was traditionally an incandescent lamp used commonly for domestic or industrial purposes. The filament-burning variety of these bulbs has become scarce following the recent EU phase-out, so why not invest in an LED equivalent such as Philips Master LED 13W GLS Bulb? This high quality 75-watt equivalent lamp draws just 13 watts of power, boasts a 25,000 hour lifespan, and comes supplied with a reassuring 3-year guarantee. For a smaller outlay Lyco stocks a selection of non-dimmable Philips LED GLS Bulbs in a choice of wattages.
LED Outdoor Lighting
Nowhere is the potential of LED technology more clearly defined than outside, where its economical use of power allows for greener, safer lighting schemes. Three LED outdoor products are described here:
Part of the fantastic potential of external LED lighting is its coupling with solar panel technology to produce what essentially becomes free, naturally-powered lighting! Solar-powered LEDs can usually gather enough juice during any day, regardless of weather, to illuminate a property or space overnight. Installed batteries are recharged, and the light is subsequently triggered either by movement sensor or a photocell (light sensor). With this in mind, Lyco offer an exciting range of LED security lights, whilst our LED Solar Lights category offers you a broader choice of daylight-powered light fittings.
One thing that makes LED so versatile is its robust nature. Being a solid-state form of lighting there’s no delicate filament or abundance of easily shattered glass, which makes LED vibration and shock-proof. It’s therefore an ideal candidate as a walkover light for oft-trodden areas such as garden decking. Usually, as with the Larch LED Walkover Lights, these lights are low voltage and come in kits of three lights with transformer and cabling. You can invariably either add individual lights or subsequent kits.
LED Garden spotlights are great for highlighting features of your garden, whether it’s that carefully assembled rockery, a spectacular tree or shrub, or a water feature. They’re particularly effective in this role again because of the inherent directional nature of LED lighting, which in turn means very little output from an LED light is wasted. Cool-running and usually low voltage, these and other LED garden lighting solutions are often safer than equivalents. They are child, pet and lawnmower friendly, since they negate any chance of a harmful shock.
LED Indoor Lighting
Regardless of whether you’re an architect, specifier, designer, electrician or end-user, LED as an indoor lighting solution is the wisest future-proof choice! To help illustrate its dominance: Swedish home furnishing giants Ikea have pledged to sell only LED lighting products by the year 2016.
LED lamps and luminaires are also an asset when trying to meet UK energy-conservation targets in new domestic property builds. Whether you install retro-fitting LED lamps or dedicated LED fittings, they add to your energy-saving tally (DER – Dwelling Emissions Rate). A technology that enjoys massive support amongst the lighting designers of today, your creative palette will never be dry when you turn to LED!
Some great choices are available for indoor LED lighting:
In a working environment LED ceiling panels such as the Robus LED Ceiling Panel provide a vastly more efficient and attractive alternative to old-fashioned arrays of flickering fluorescent tube. High quality LED panels such as the Robus are designed to produce an attractive, diffused light with an even spread of illumination, and they’ll save you significant money in running costs and non-existent maintenance costs. These are ideal as easily installed, retro-fitting panel replacements in offices, hospitals, schools, or any other place where quality of light and low energy usage might be appreciated!
The possible uses for LED downlights are many. In a business environment they’re ideal for foyers and reception areas, corridors, washrooms, canteens, and small offices. They’re also great for home use in hallways, kitchens and bathrooms. One smart choice in LED downlights is the Dimmable Spotlight, which is fire-tested for 30, 60 and 90-minute ceilings, and boasts an IP65 rating that makes it suitable for installation in most areas of a bathroom. Switching to LED has saved many businesses literally thousands of pounds in their annual energy and maintenance costs, thanks to phenomenally long lifespans and around 80-85% extra energy-efficiency over incandescent solutions.
No technology is better suited to cabinet lighting than LED. Extremely compact designs are possible through the compact size of an LED, while its cool output makes LED ideal for interior cabinet and display lighting with less likelihood of burnt hands or heat-damaged exhibits! Under-cabinet lights are a perfect application for LED, too, with recessed or surface-mounted pucks being easily installed. One such possibility is the set of 3 LED downlights, available in white or chrome finish. Again, the directional nature of LED makes it perfect for this type of focused task-oriented application, with more wide-spreading beams being possible where necessary through diffusion.
A recent proprietary survey by McKinsey & Company—a global management and business adviser—predicted LED will be the most commercially viable ‘clean’ technology in the year 2020.
In the near future LED prices are expected to steadily drop because of new and less expensive manufacturing processes, whilst the real-world luminous efficiency we’ve discussed is expected to creep towards the 200 lm/W mark by 2014. Development is intensifying at a remarkable rate, in part because of commitments made by several Asian countries to meet LED percentage targets in the year 2015.
Top lighting designers and vendors are committing more and more to the technology that stands head and shoulders above all others as an eco-friendly and cost-effective lighting solution for now and the future. Exceeding the expectations even of Haitz’s law, LED has rapidly become incredibly efficient at an ever-dwindling cost. With a vast range of high quality and exciting products already on the market, few investments can be more worthy, or are more likely to give you a quick return, than LED.
Seeing stars –LED streetlights
If you live in an urban environment—and 90% of UK dwellers do—you’re permanently cut off from the night sky by what is known as light pollution. This concept would have been totally alien to our distant ancestors, who enjoyed a deeper, more profound connection with the universe. Indeed, you can easily get a sense of what you’re missing by travelling to certain rural areas of Britain, where the skies are still impressively dark—lit only by a clear night and thousands of multi-coloured stars.
The light pollution that has the greatest collective impact on our mood and sense of place is probably ‘sky glow’, which is the type of noise pollution that prevents us from seeing stars. Sky glow refers to the enshrouding glow visible above urban areas, caused by poorly directed or controlled artificial illumination. Installation of LED streetlamps directly addresses this problem, and at the risk of becoming repetitious it does so through its directional nature. In fact LED lighting is often a little too focused for its intended purpose, so LED streetlight design tends to include a modifying lens for greater coverage of pedestrian areas as well as the road.
Across the world cities are adopting LED lighting, sometimes powered by solar energy but always with numerous advantages over existing solutions:
- Lifespan – an LED streetlight will last around 3-5 times longer than a conventional high pressure sodium street lamp, drastically reducing maintenance costs.
- Energy saving – around 40-80% less electricity is used by LED than in a conventional street lamp.
- Colour accuracy – many street lamps produce a monochromatic light that makes it impossible to discern colour. Greater colour accuracy in LED allows increased safety and versatility in surrounding road markings, as well as being preferential for crime reduction purposes.
- Ambient temperature – LED lights are inherently resistant to extremes of cold.
- Environmentally friendly – lower CO² emissions, and no mercury or lead content.
- Controllability – instant-on light with no warm up time.
So much more than just a passing phase, LED lighting has the potential to deliver us in some small way from whence we came, and provide a better world for all.
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