What are LEDs?

LED stands for light-emitting diode. LEDs are small light sources that become illuminated by the movement of electrons through a semiconductor material.

Low-Powered LEDs
LEDs used to draw
attention to something,
such as an exit sign,
a green power button
on a computer,
or a red blinking light
on a video camera.
High Power LEDs
LEDs used to illuminate an area.
ENERGY STAR qualified LED lighting
uses multiple illuminator LEDs inside
a fixture to produce white light.

How are LED lighting products different from other lighting, like fluorescent or incandescent?
LED lighting is more efficient, durable, versatile and longer lasting than incandescent and fluorescents lighting. LEDs emit light in a specific direction, whereas an incandescent or fluorescent bulb emits light — and heat — in all directions. LED lighting uses both light and energy more efficiently.

For example, an incandescent or compact fluorescent (CFL) bulb inside of a recessed can will waste about half of the light that it produces, while a recessed down light with LEDs only produces light where it’s needed — in the room below.

Incandescent bulbs create light by passing electricity through a metal filament until it becomes so hot that it glows. Incandescent bulbs release 90% of their energy as heat. In a CFL, an electric current is driven through a tube containing gases. This reaction produces ultraviolet light that gets transformed into visible light by the fluorescent coating (called phosphor) on the inside of the tube. A CFL releases about 80% of its energy as heat. LED lighting products use light emitting diodes to produce light very efficiently. The movement of electrons through a semiconductor material illuminates the tiny light sources we call LEDs. A small amount of heat is released backwards, into a heat sink, in a well-designed product; LEDs are basically cool to the touch.

Basic parts of LED lighting
LED lighting starts with a tiny chip (most commonly about one square millimeter) comprised of layers of semi-conducting material. LED packages may contain just one chip or multiple chips, mounted on heat-conducting material called a heat sink and usually enclosed in a lens. The resulting device, typically around 7 to 9 mm on a side, can be used separately or in arrays. LED devices are mounted on a circuit board, which can be programmed to include lighting controls such as dimming, light sensing and pre-set timing. The circuit board is mounted on another heat sink to manage the heat from all the LEDs in the array. The system is then encased in a lighting fixture, architectural structure, or even a “light bulb” package.

LED lighting is ultra-compact and dramatically more efficient than traditional incandescent bulbs – up to 85% more efficient – and over 10% more efficient than compact fluorescent bulbs (CFL’s).

Just imagine, you could install an LED bulb in your newborn’s room today, and probably not have to replace that bulb until your child is off to college. And, because LED bulbs are based on solid-state lighting technology that emits light from a chip, they produce minimal heat and there is no filament to burn out, as with incandescent bulbs. Nor do they contain mercury and other toxic material.