LEDs, or light-emitting diodes, are a form of solid-state lighting that is extremely efficient and long-lasting. While incandescent and fluorescent lights consist of filaments in glass bulbs or bulbs that contain gases, LEDs consist of small capsules or lenses in which tiny chips are placed on heat-conducting material.
Size and Efficiency
LEDs measure from 3 to 8 mm long and can be used singly or as part of an array. The small size and low profile of LEDs allow them to be used in spaces that are too small for other lightbulbs. In addition, because LEDs give off light in a specific direction, they are more efficient in application than incandescent and fluorescent bulbs, which waste energy by emitting light in all directions.
The life of a high-power white LED is projected to be from 35,000 to 50,000 hours, compared to 750 to 2,000 hours for an incandescent bulb, 8,000 to 10,000 hours for a compact fluorescent and 20,000 to 30,000 hours for a linear fluorescent bulb. LED lifetimes are rated differently than conventional lights, which go out when the filament breaks. Typical lifetime is defined as the average number of hours until light falls to 70 percent of initial brightness, in lumens. LEDs typically just fade gradually.
Conventional lightbulbs waste most of their energy as heat. For example, an incandescent bulb gives off 90 percent of its energy as heat, while a compact fluorescent bulb wastes 80 percent as heat. LEDs remain cool. In addition, since they contain no glass components, they are not vulnerable to vibration or breakage like conventional bulbs. LEDs are thus better suited for use in areas like sports facilities and high-crime locations.