LED streetlights combine enormous savings potential with superior lighting performance relative to incumbent technologies. LEDs are particularly suited for street lighting applications (particularly “cobra-head” lights) and offer many benefits, including:
Reduced energy costs: LEDs are able to achieve equivalent or improved light output while consuming 50% to 70% less power compared to their HID counterparts. Many utilities, including PG&E, offer special tariffs for LED streetlights based on rated wattages, which are typically much lower than HPS streetlights. These avoided energy cost savings help to offset the higher initial cost of LEDs.
Lowered Maintenance Costs: LED light sources last longer, requiring fewer trips up the pole to replace burnt-out lamps. As a solid-state lighting technology, LEDs are more resistant to vibration and impact when compared to HID light sources.
Several LED streetlight products listed by the DesignLights™ Consortiumclaim useful operating hours of over 50,000 hours, far greater than HPS lamp lifetimes (generally 20,000 hours or less). One of the most attractive features of LED luminaires is the promise of lower maintenance costs compared to traditional HID fixtures.
Improved lighting quality: LEDs provide greater options on color and generally provide whiter light with better color rendering. Properly designed, the fixtures can significantly improve acuity.
In addition, whereas HID light sources typically create “hot spots” with more light than needed immediately beneath the fixture and “cold spots” surrounding the hot spot, LEDs can provide a more uniform light distribution that further improves visibility.
Reduced light trespass: Unlike conventional incumbent technologies, LEDs are inherently directional light sources, meaning that they can place the light where it is most needed and reduce light going in unwanted directions (such as into residences through windows).
Enhanced controllability: Unlike standard HID light sources, LEDs allow for instant on/off and light level adjustment, making them more suited for use with advanced lighting control systems. These systems can generate additional energy savings by dynamically adjusting light levels based on real-time lighting needs.
For example, in the event of emergency controllable lighting could prove useful to first responders who may need to increase (or even decrease) lighting.
Reduced emissions: Reduced energy consumption delivers significant reductions in greenhouse gas emissions, supporting efforts to combat climate change. Upgrading 200,000 streetlights in the San Francisco Bay Area would result in 100,000 metric tons of avoided CO2 emissions over five years – the equivalent of taking nearly 10,000 cars off the road.
(Potential) reduction in crime: When comparing the rate of nighttime crime (7:00 p.m. to 7:00 a.m.) before and after installing new LED streetlights, Los Angeles found that crime (such as burglary, theft and vandalism) rates dropped by 10% between 2009 to 2011. Many factors can affect crime rates, but officials in Los Angeles believe the improved light quality was an important factor in the reduced crime rate, deterring criminals who take advantage of poor color rendering and “cold spots” produced by incumbent technology.