What are LEDs?

LED stands for light emitting diode. It was first developed in 1962 which generates light through the movement of electrons through a semiconductor material. Even though LEDs have long been in use in the electronics industry as indicator lights, only in the last decade have they been utilized for general illumination purposes.

What is SSL?

LEDs are part of a family of lighting technologies called Solid-State lighting (SSL), and is most commonly seen in the form of Light Emitting Diodes (LEDs), when applied efficiently can revolutionize the efficiency, appearance, and quality of lighting as we know it.

The term "solid state" refers commonly to light emitted by solid-state electroluminescence, as opposed to incandescent bulbs (which use thermal radiation) or fluorescent tubes. Compared to incandescent lighting, SSL creates visible light with reduced heat generation or parasitic energy dissipation. Most common "white" LEDs convert blue light from a solid-state device to white light spectrum using photoluminescence, the same principle used in conventional fluorescent tubes.

The U.S. Department of Energy (DOE) estimates that the rapid adoption of LED lighting in the U.S. over the next 20 years can:

• Deliver savings of about $265 billion
• Avoid 40 new power plants
• Reduce lighting electricity demand by 33% in 2027

How does LED lighting differ to fluorescent or incandescent?

LED lighting is more efficient, durable, versatile and longer lasting than incandescent and fluorescents lighting. LEDs also 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 to create light. Incandescent bulbs therefore release 90% of their energy as heat.
• In a compact fluorescent lamp (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 on the inside of the tube. A CFL therefore 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 which means LEDs are cool to the touch.

What is "White Light"?

There are two primary ways of producing high intensity white-light using LEDs. One is to use individual LEDs that emit three primary colors (red, green, and blue) and then mix all the colors to form white light. The other is to use a phosphor material to convert monochromatic light from a blue or UV LED to broad-spectrum white light, much in the same way a fluorescent light bulb works.