High-Pressure Sodium (HPS) lights have remained a popular street lighting solution. Despite their widespread usage, however, HPS lamps display numerous deficiencies, particularly when compared with newer lighting technologies.
HPS visibility issues are compounded by its inherent color limitations. High-Pressure Sodium lamps generate narrow spectrum light, which appears to us as a dull yellow glow. Hampered by an extremely low Color Rendering Index, these lights simply cannot accurately reproduce colors.
LED lamps with a color temperature of 3.500-4.200 K generate significantly more natural white light than do yellow HPS lamps. The more natural ‘daylight’ spread far and wide by LEDs in turn creates greater visibility and safer conditions for both motorists and pedestrians.
While LEDs offer excellent visibility and color accuracy, they lose nothing when it comes to energy efficiency. In fact, they significantly outperform HPS lamps in this category. When comparing the two, energy-saving light bulbs consume 40-80% less electricity than do standard HPS lamps.
In terms of actual wattage, a 30W LED lamp approximates the light output of a 80W HPS. This feat of efficiency stems from the directionality of LEDs, which focus light downwards and spreads illumination evenly over a given area. As a result, one LED lamp requires significantly less wattage than does an HPS to illuminate the same area.