New technology has pushed LEDs to the forefront of high power lighting. While some rely on outdated information to downplay the efficiency of LEDs, continued improvements in LED technology have made LEDs not only a viable option to replace traditional street lighting, but a no-brainer for saving energy without compromising on effective lighting.

Like a normal diode, the LED consists of a chip of semiconducting material impregnated, or doped, with impurities to create a p-n junction. As in other diodes, current flows easily from the p-side, or anode, to the n-side, or cathode, but not in the reverse direction. Charge-carriers—electrons and holes—flow into the junction from electrodes with different voltages. When an electron meets a hole, it falls into a lower energy level, and releases energy in the form of a photon.

The wavelength of the light emitted, and therefore its color, depends on the band gap energy of the materials forming the p-n junction. In silicon or germanium diodes, the electrons and holes recombine by a non-radiative transition which produces no optical emission, because these are indirect band gap materials. The materials used for the LED have a direct band gap with energies corresponding to near-infrared, visible or near-ultraviolet light. (Wikipedia).

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  Parts of an LED
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  The inner workings of an LED
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  Parts I-V diagram for a diode an LED will begin to emit light when the on-voltage is exceeded.

*12 hours a day, cable loss 6%, transformer loss 3%.

• Advantages of LED Lighting
  Extremely long life (50,000 hours)
  Highly Efficient and Energy Saving (60%-70%)
  Instant starting, no Cold-Start
  Bright, white light (CRI >= 80)
  Improved visibility and security
  
  Illumination of LED Street Lights
• Applications of LED Lighting
  Major Roadways
  Residential Streets
  Pedestrian Walkways
  Parking Lots
  Docks and Piers
  
  Illumination of High Pressure Sodium light