Opto-electronics is an exciting area and we predict, that in the near future, white LED lighting applications will be powerful and cheap enough to replace incandescent lighting for everyday use in our homes, in street lights, outdoor signs, and offices.
There is no comparison between the cost of LED lights vs. traditional incandescent options. With incandescent bulbs, the true cost of the bulb is the cost of replacement bulbs and the labor expense and time needed to replace them. These are significant factors, especially where there are a large number of installed bulbs. For office buildings and skyscrapers, maintenance costs to replace bulbs can be enormous. These issues can all be virtually eliminated with the LED option.
The key strength of LED lighting is reduced power consumption. When designed properly, an LED circuit will approach 80% efficiency, which means 80% of the electrical energy is converted to light energy. The remaining 20% is lost as heat energy.
Compare that with Incandescent bulbs which operate at about 20% efficiency (80% of the electrical energy is lost as heat). In real money terms, if a 100 Watt incandescent bulb is used for 1 year, with an electrical cost of 10 cents/kilowatt hour, R88 will be spent on electricity costs. Of the R88 expense, R70 will have been used to heat the room, not light the room. If an 80% efficient LED system had been used, the electricity cost would be R23 per year – there would be a cost savings of R65 on electricity during the year. Realistically the cost savings would be higher as most incandescent light bulbs blow out within a year and require replacements whereas LED light bulbs can be used easily for a decade without burning out.
The main limitation to the adoption of white LED lighting as a lighting standard is the current high cost of led bulbs. Although the cost keeps going down, LED light bulbs are still expensive.
;Although LED’s are expensive, the cost is recouped over time and in energy cost savings.
Factor in that it is significantly cheaper to maintain led lights, the best value comes from commercial use where maintenance and replacement costs are expensive. Traffic lights and outdoor signs, for example, are being switched over to LED’s in many cities. Smaller arrays, such as those in flashlights, headlamps and small task lights are great for specialty and outdoor use. LED based automotive headlights are current being used in high end luxury cars.
It will be interesting to see what developments are coming for more residential applications of LED lights. LED lighting technology has been researched and developed for the past two decades and we are beginning to see practical applications from this work. There is already wide spread use of LED traffic signs and LED headlights where a premium is placed on a reliable light source that is cheaper and less labor intensive to maintain. We in the industry are certain that tomorrows LED lights will last longer and consume even less power than todays energy efficient bulbs. LED lighting will be used to replace virtually every type of light, bulb, and lamp that is currently in use.