LED street light

LED street light

LED street light beam pattern

An LED street light (also called LED road lighting) is an integrated LED (Light Emitting Diode) light fixture that is used as street lighting. Because they are more energy efficient than other technologies used for street lighting, LED street lights can save on the cost of keeping streets well lit during the night.

Overview

An LED street light is an integrated light that uses LEDs as its light source. These are considered integrated lights because in most of the cases the luminaire and the fixture are not separate parts (except LEDGine based luminaires). New in manufacturing, the LED light cluster is sealed on a panel and then assembled to the LED panel with a heat sink to become an integrated lighting fixture.

Installations

LED street lights have been installed or announced for installation in several large cities as well as smaller cities throughout the world. Cities that have announced their intention to install LED street lights include:

• Boston
• Worcester

Cities that have installed at least some LED street lights include:

• Toronto
• Budapest
• New York City
• St. John's, Newfoundland and Labrador
• Halifax, Amherst, Annapolis Royal, Wolfville, Halifax International Airport, Truro, Antigonish, and many other smaller towns in Nova Scotia have installed fixtures manufactured and designed by a company in that province.

Energy efficiency

The life span of an LED as compared to other light sources

The primary appeal of LED street lighting is energy efficiency compared to incandescent bulbs of the same luminance. Research continues to improve the efficiency of newer models. One such advance can be found in a street light product created by Lighting Science Group. One model of LED street lights produced by this group is up to 60% more efficient than previous models, lasts for 12 years and allows for cost recovery through energy savings in only three years.

An LED street light based on a 901 milliwatt output LED can normally produce the same amount of (or higher) luminance as a traditional light, but requires only half of the power consumption.

Design and style

Different designs have been created that incorporate various types of LEDs into a light fixture. The trend in the world is to use high power 1 watt LEDs, but some companies use low power LEDs in their products, including several low power LEDs packed together to perform the same purpose as a single high power LED. The shape of the LED street light depends on several factors, including: LED configuration; the heat sink used with the LEDs; or, aesthetic design preference.

Heat sinks for LED street lights are similar in design to heat sinks used to cool other electronics such as computers. Heat sinks tend to have as many grooves as possible to facilitate the flow of hot air away from the LEDs. The area of heat exchange will directly effect the lifespan of the LED street light.

The lifespan of LED street lights is determined by its light output compared to its original design specification. Once its brightness decreases by 70%, an LED street light is considered to be at the end of its life.

Most LED street lights have a lens on the LED panel, that is designed to cast its light in a rectangular pattern, an advantage compared to traditional street lights, which typically have a reflector on the back side of a high-pressure sodium lamp. In this case much of the luminance of the light is lost and produces light pollution in the air and surrounding environment. Such street lights also can cause glare for drivers and pedestrians.

External links

Exact description of hundreds of LED Lightings