Types of Lamp Technologies
|Types of lamp||Luminous Efficacy||Color Rendering properties||Lamp lifes in hrs||Remarks|
|High Pressure Mercury Vapor(MV)||35-36 Im/W||Fair||10000-15000||High energy use, poor lamp life|
|Metal Halide(MH)||70-130 Im/W||Excellent/W||8000-12000||High luminous efficacy, poor lamp life|
|High Pressure Sodium Vapor(HPSV)||50-150 Im/W||Fair||15000-24000||Energy-Efficient, Poor color rendering|
|Low Pressure Sodium Vapor(LPSV)||100-190 Im/W||Very Poor/W||18000-24000||Energy-Efficient, very poor color rendering|
|Low Pressure Mercury Fluorescent Tubular lamp(T12 & T8)||30-90 Im/W||Good||5000-10000||Poor lamp life, medium energy use, only available in low wattages|
|EE Fluorescent Tubular lamp(T5)||100-120 Im/W||Very Good/W||15000-20000||EE, long lamp life only available in low wattages|
|Light Emitting Diode(LED)||70-180 Im/W||Good||40000-90000||High energy savigs, low O & M, long life, no mercury, high capital cost and evolving technology|
What is LED Street Lighting?
While LED technology for street lighting is relatively new, the science behind it is actually well understood because LEDs themselves have been around for decades. Basically, an LED is just a light bulb without the filament and its color and illumination intensity are dictated by the movement of electrons in the semiconductor material. And because LEDs are based on solid state technology, they can more readily be controlled and programmed which makes them one of the most versatile and flexible light sources available today. The life span of an LED street light can exceed 50,000 hours, which is equivalent to almost six years of continuous operation which equates to 12 years of life when in operation 12 hours a day
LED lights contain no toxic materials and are 100% recyclable. Because of their long life, they can significantly reduce landfills and bulb disposal costs compared to conventional street lights.
|Type of Road||Road Characteristics||Average level of Illumination on Road Surface in LUX||Ratio of Minimum/Average Illumination||Type of Luminaire Preferred||Min:Max (%)||Mounting Height of Luminaires|
|A-1||Important traffic routes carrying fast traffic||30||0.4||Cut-off||33||9 to 10 meters|
|A-2||Main roads carrying mixed traffic like city main roads/streets, arterial roads, throughways||15||0.4||Cut-off||33||9 to 10 meters|
|B-1||Secondary roads with considerable traffic||8||0.3||Cut-off or Semi-Cut-off||20||7.5 to 9 meters|