Simply put: the reason that traditional lighting, such as incandescent bulbs, are significantly less efficient than LEDs is because of the heat energy they produce as a by-product. As a secondary factor, wasted energy places stress on a lighting unit, significantly reducing the lifespan of the unit.
Incandescent lights operate using a filament. Electric current is then passed through the filament, heating it until it’s so hot that it glows and gives off light. This process is extremely inefficient due to the amount of energy wasted on the generation of heat (around 90%), which goes completely un-utilised. Incandescent lights are also prone to burning out because of the stress the filament comes under, needing to be replaced regularly.
CFL (compact fluorescent lamp) uses a different system to incandescent. Electric current is passed through a bulb tube filled with mercury vapour and argon, generating ultraviolet light. The ultraviolet light reacts with a fluorescent coating on the inside of the tube, producing useful illumination. A CFL will last around ten times longer than a comparable incandescent and use around 75% less energy.
LED (light emitting diode) again functions entirely differently. When the LED is active, electrons recombine with electron holes (the opposite of an electron) and release photon energy, otherwise known as electroluminescence. Virtually no energy is wasted by generating light in this manner. LEDs offer around an 80% energy saving and can last twenty-five times longer than a comparable incandescent.
The direct saving in carbon emissions comes from the diode needing much less electricity to function. The indirect savingcomes into effect when the LED outlives it’s incandescent and fluorescent counterparts, resulting in a carbon saving in the manufacturing process, materials, transport and packaging that are involved in creating and delivering a replacement bulb.
In addition to high luminance street and interior lighting, low luminance LEDs, often referred to as lighting indicators, are also found in many types of vehicles, home appliances, remote controls, mobile phones, computers and millions more devices.