Light-emitting diodes (LEDs) are solid-state devices that convert electric energy directly into light of a single color. Because they employ “cold” light generation technology, in which most of the energy is delivered in the visible spectrum, LEDs don't waste energy in the form of non-light producing heat. In comparison, most of the energy in an incandescent lamp is in the infrared (or non-visible) portion of the spectrum. As a result, both fluorescent and HID lamps produce a great deal of heat. In addition to producing cold light, LEDs:
Can be powered from a portable battery pack or even a solar array.
Can be integrated into a control system.
Are small in size and resistant to vibration and shock.
Have a very fast “on-time” (60 nsec vs 10 msec for an incandescent lamp).
Have good color resolution and present low, or no, shock hazard.