By David MacCallum
In recent years, light-emitting diode (LED) technology has been embraced by the pool and spa industry. While LED technology used to be an expensive, specialized alternative, today’s pool and spa fixtures are brighter, more energy efficient and less expensive than their first-generation predecessors.
Designed to last longer and consume less energy than traditional alternatives, LED lighting options are becoming increasingly prevalent in pool, spa and water feature applications.
A brief history of LED
The technology has been around for almost 50 years; the first practical LED was developed at General Electric Company in 1962 and became commercially available in the late 1960s.
LED devices convert electronic energy directly into light, the brightness of which can then be controlled. The main component of an LED is a chip of semiconducting material modified to create what electrical engineers call a positive-negative (p-n) junction. Current flows from the positive side (anode) to the negative side (cathode), only in that direction. Electrons and holes, both of which carry a charge, flow into the junction from electrodes of varying voltages. When an electron meets a hole, it falls to a lower energy level and releases excess energy in the form of a photon. The wavelength—and, therefore, colour—of the light emitted when the electron meets the hole depends on the energy gap between the materials that form the p-n junction.
Early LEDs were red, first used as replacements for incandescent indicator lights in expensive laboratory equipment. As production costs decreased and they became more affordable, red LEDs began showing up in electronics such as remote controls, TVs, radios, telephones, calculators and watches, still serving as indicator lights (they were not yet bright enough to provide illumination). Later, other colours became widely available and were used in appliances and equipment.
Eventually, as the technology continued to improve, light output and brightness increased, opening the door to illumination applications. Today, LED technology is used for a wide range of purposes, including airplane navigation lights, traffic lights, children’s toys and automobile headlights and turn signals.
