Luminous Efficacy
As the technology matures, high-power LED light sources are now capable of meeting the requirements for standard street lighting. While conventional high-pressure sodium lamps offer a luminous efficacy of 100 lm/W, standard high-power LEDs typically range from 50 to 60 lm/W (though figures up to 80 lm/W are achievable with imported chips). Higher luminous efficacy translates to better energy efficiency, making it a critical metric when selecting LED streetlights. However, as there are no explicit industry standards regarding this specific parameter, careful verification is essential during procurement.
Lumen Depreciation
To cut costs, some manufacturers utilize hundreds of low-power (0.5W) LEDs. These low-power LEDs suffer from severe lumen depreciation; their lifespan-defined as the time it takes for light output to drop to 80% of its initial level-is merely 1,000 hours. Consequently, such low-power LEDs are entirely unsuitable for streetlights, which require long-term durability. High-power LEDs (typically 30W or higher) offer significantly better performance regarding lumen depreciation.
Weight Considerations
Due to their sophisticated technology and complex composition, some high-power LED lamp heads are significantly heavier than conventional high-pressure sodium lamps, placing greater demands on the supporting structures. However, manufacturers have been actively reducing the weight of LED lamp heads; weights have dropped from approximately 30 kg per unit to just over 10 kg, with a continuing trend toward further reduction.
Heat Dissipation
As LEDs are semiconductor devices, their lifespan is effectively over when the chip's light output drops to 30% of its initial level due to thermal effects. While high-power LED streetlights theoretically offer a lifespan of 30,000 to 50,000 hours, this longevity relies heavily on effective heat dissipation. Notably, some domestic manufacturers have already adopted world-leading pin-fin heat dissipation technology.
