LED Lighting Uses 70-90% Less Energy

LED, or light-emitting diode, is a highly efficient, solid-state lighting (SSL) technology in which nearly all the energy used produces light rather than waste heat.  In addition to being inherently more efficient than high pressure sodium (HPS) and other traditional light sources, LED technology has characteristics that enable higher wattage HPS fixtures to be replaced with lower wattage LED fixtures. For example:

          Optical Control: LED lighting provides uniform light distribution, while traditional light sources direct most of their light output to a small area directly under the fixture.

          Lumen Depreciation: LED lighting sustains light output for most of its long life, while the rapid depreciation of light output from traditional light sources necessitates the use of higher wattage fixtures to maintain minimum light levels over their useful life.

          Adaptability: LED lighting can be field adjusted for different applications, in contrast to HPS lighting which is offered only in fixed wattages, and LED lighting can be easily controlled (dimmed) to save additional energy.

Converting existing street and area lighting to LED reduces energy use by 70% or more, depending on the application, and additional savings can be achieved by dimming during times of day when traffic volume or other factors justify lower light levels. In parking garages LED lights can be combined with controls and motion sensors so that they dim automatically at times of day when activity is low, then instantly return to full illumination when activity is detected.

LED Lighting Reduces Maintenance Costs

In contrast to LED lighting, HPS and other traditional types of area lighting require ongoing maintenance to replace failed lamps and ballasts (HPS lamps last 4-5 years, ballasts 8-10 years).  The associated maintenance costs are substantial, with 20% or more of the lights in a traditional streetlight system requiring a visit from a bucket truck crew each year.  Most LED street lights carry a 10-year warranty and will need little or no maintenance for much longer.