Although LED lighting has beenpart of our everyday life for decades now – mainly in the form of signallinglighting or in the displays of watches and calculators – they only recently became suitable for household use; that is replacing traditional or other energy-saving forms of lighting. LED lights are the best available solution for energy-saving lighting solutions from the points of view of the rate of saving energy, heat emission (LEDs are cool running), the lights’ lifespan and even health, since fluorescent lights’ flickering can cause migraine or epileptic attacks. Energysaving is one of the currently pressed issues both by green organizations andgovernments, trying to make people save both energy and money by regulations.
LED energy saving solutions might require more investment at the beginning but are definitely worth it, considering the many advantages. Another sign of the “bright” future of LED lighting is the amount of research lighting companies and governments areputting into the field. Philips, one of the major companies in lighting,switched most of his resources from research in other forms of lighting, andalso cooperates with CREE – a leading LED manufacturing company.
Although LED solutions arealready suitable for replacing most of our lights, there are still plenty ofareas where research is required. One is the price of LED production, whichneeds to be lowered in order to make the solution accessible for the masses. In household lighting obviously white coloured light bears significance. White light is the most complicated and most expensive to create with LED lights -unlike in the case of other lighting forms. Researchers are therefore lookingfor more intensive lights, cheaper production solutions and better designs.
As for light intensity, CREE recently announced that they achieved to get a single LED emitting 208 Lumens with 1W power consumption. Although this news is amazing, and the application of the solution could ideally start soon, design problems can occur with the application.
Other researchers looking for brighter solutions are the Universityof Glasgow team forinstance. LED is a form of solid state lighting (SSL), and one of the major problems deriving from this fact is the most of the photons get trapped within the case of the light. This research group is looking for cheaper ways of creating a large number of microscopic holes in the casing, so that the lights would become more intensive.
The University of Cambridge research group used a new combination of the matter, and cheaper ways of producing gallium-nitride semiconductor material. Another factor in creasing the intensity of the light was placing it on a silicone base. With these changes the group was able to create individual LED lights with a lifespan of 100 000hours, which are also dimmable. These LEDs are expected to be on the market around 2012 but new research groups are getting involved in LED research over the globe.
Increased light intensity of individual LEDs does not necessarily mean that they can be applied in household use immediately. Since LED lights need to be placed into the limited space of a regular light bulb a special design is required for their application. Although LEDs are generally considered cool running forms of lighting, they do emit some heat, even though it is only a fragment of what we are used to with conventional lights. However, LEDs are also very sensitive to heat, and are therefore any increase in heat can reduce their lifespan even radically. In the case of high power LEDs this is doubly true, since they emit more light and heat as well. The design of LED light bulbs or spotlights concentrate mainly on effective thermal management, so that LEDs – even if several are placed within a bulb, and therefore generate more light and heat – would not lose their brightness and lifespan.
Another field researched is trying to find solutions for dimming LED lights with existing dimming systems. The technology of dimming LED bulbs is already available, however LEDs are sensitive to uneven voltage often occurring with electronic dimmers, so most dimmable LED solutions only work with traditional TRIAC dimming technologies.
In the brighter future LEDs will be suitable for replacing all dimmable lighting solutions and traditional forms of lights as intensive as 100W. Considering the amount of efforts put into LED research, we will hopefully not wait too long for this.