Light-Emitting Diode (LED) Lighting
What are LEDs?
Light-emitting diodes (LEDs) are semiconductor devices that emit light when an electric current passes through them. Initially used to produce a red indicator light in such things as electronic devices, LEDs are now available in a wide range of colours and light intensities. They can be found in traffic lights, automotive brake lights and headlights, Christmas lights, flashlights and cellphone screens, to name a few. More importantly, they are increasingly being used for general, white lighting in homes and businesses.
What is the advantage of LEDs as a lighting source?
LEDs are highly efficient, which means they use very little electricity to produce light, and all that light is emitted in a specific direction. By comparison, standard incandescent light bulbs are only about 10 per cent efficient, with the remaining 90 per cent of their power use lost as heat. Even compact fluorescent lights (CFLs) waste much of their energy. As a result, LEDs use at least 75 per cent less energy than incandescent bulbs and about half that of CFLs. Considering that about 15 per cent of the typical home's electrical use is for lighting, switching to LEDs represents a big savings in that electrical use. With a lifespan of between 50,000 and 100,000 hours, LEDs also last some 50 times longer than incandescents and up to 10 times longer than CFLs. In other words, an LED in a typical house could last for decades before needing to be replaced.
Do LEDs have other advantages over other types of lighting?
Is the light they produce too directional for area lighting?
While some LEDs - such as small headlamps and decorative lights - produce small directional light, high-powered LEDs use multiple illuminators inside the fixture to produce area lighting similar to that of incandescent or CFL bulbs.
How much of this lighting do you need to replace an existing incandescent bulb?
Currently, a 60-watt incandescent bulb can be replaced with a similar-sized and shaped LED using as little as eight watts of power.
What lighting applications are LEDs typically designed for?
LEDs can be found in track lights, spotlights, shelf-mounted display and task lights, portable desk lamps, recessed down lamps, outdoor step and pathway lights, porch lights, and tape, or strip, lights.
Are LEDs widely available?
Not yet, but a growing number of stores and online retailers that sell lighting products are now offering them. Before you buy, ask the retailer if they have LED light displays, so you can check the quality and colour of the light.
Are LEDs expensive?
Compared with other types of lighting, yes. Area lighting bulbs can range from $50 to more than $100, though prices continue to drop as the technology and market improves, much as it did for CFLs over the past decade.
How much can I save on my electricity bill if I install one or more LEDs?
An eight-watt LED that's on eight hours a day, 365 days a year, costs about $2.35 a year to operate, at 10 cents per kilowatt hour. An equivalent incandescent bulb would cost about $17.50 a year and a CFL about $4.70. While it would take a number of years to pay off the upfront cost of LEDs, their 50,000-hour-plus lifespan makes the economic argument much more attractive.
Because these lights are so efficient, should I just leave them on for long periods of time?
No. Energy conservation is always the smartest thing to do: a light that's turned off uses no energy. So turn off LEDs that are not in active use.
Other than saving money on my long-term lighting bill, why should I consider installing LED lights?
Canada will phase out the sale of incandescent bulbs by 2012. Thereafter, you'll only be able to buy more efficient lights such as CFLs and LEDs. The federal government estimates the ban will reduce Canada's greenhouse gas emissions by more than six million tonnes a year. The U.S. Department of Energy estimates that rapid adoption of LED lighting over the next 20 years could deliver national savings of about $265 billion, avoid the construction of 40 new power plants and reduce lighting electricity demand by 33 per cent.
Where does it make the most sense to install LEDs?
They're best used where your lights are operating the most hours such as the kitchen, living room and other high-traffic areas. It also makes sense to install LEDs in areas that are hard to reach, because it's unlikely they'll have to be replaced for many years. Over the same time period (50,000-plus hours), you might have to replace an incandescent bulb more than 40 times.
Are all LEDs well designed?
Although the overall quality of LEDs has improved markedly in recent years, not all makes are well designed or built. ENERGY STAR has started to make a number of LED fixture types eligible for its certification program and is currently developing standards for LED bulbs designed to replace regular screw-base incandescent bulbs. In the meantime, it suggests buyers of LED replacement bulbs check for warranty information and save receipts in case of early failure or dissatisfaction with the light quality.
What are OLEDs?
Organic Light-Emitting Diodes are a new form of LEDs, in which a layer, or film, of organic material between two conductors is charged with an electric current to produce brilliant images in thin TV screens, computer monitors or portable screens for cell phones and the like. An emerging use of this OLED technology is to create energy-efficient, bright white light. Several companies are starting to manufacture these thin lighting panels, which can be flexible and even transparent.
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