LED lights can be more efficient, durable
Light–emitting diodes (LEDs) produce visible light very efficiently when an electrical current passes through semiconductor material inside them.
LED lighting differs from incandescent and compact fluorescent lighting (CFL) in several ways, and it can be more efficient, durable, versatile and longer lasting.
LEDs are directional light sources, which means they emit light in a specific direction, unlike incandescent and compact fluorescent bulbs, which emit light and heat in all directions. For this reason, LED lighting is able to use light and energy more efficiently in many applications. However, it also means that sophisticated engineering is needed to produce an LED light bulb that shines light all around like an incandescent A-shape bulb.
Incandescent bulbs produce light using electricity to heat a metal filament until it becomes white hot or is said to incandesce. As a result, incandescent bulbs release 90 percent of their energy as heat.
In a CFL, an electric current flows between electrodes at each end of a tube containing gases. This reaction produces ultraviolet (UV) light and heat. The UV light is transformed into visible light when it strikes a phosphor coating on the inside of the bulb.
Because LED lighting systems don’t radiate heat, the heat produced from the power going into the product must be drawn away from the LEDs. This is usually done with a heat sink – a passive device that absorbs heat and dissipates it into the surrounding environment.
Common LED colors include amber, red, green and blue. There is actually no such thing as a white LED. To get white light, color LEDs are mixed or covered with a phosphor material that converts the color of the light. Colored LEDs are widely used as signal lights and indicator lights, like the power button on a computer.
LEDs are also incorporated into bulbs and fixtures for general lighting applications. Because they are small, they provide unique design opportunities.