What is the luminous efficacy of high-mast lights?
The luminous efficacy of light sources used in high-mast lights varies significantly across different technological eras.
Traditional High-Pressure Sodium (HPS) lamps: Luminous efficacy is approximately 80–120 lm/W (initial), but color rendering is very poor (CRI ≈ 20).
Traditional Metal Halide (MH) lamps: Luminous efficacy is approximately 65–100 lm/W, with moderate color rendering (CRI ≈ 65–85).
Modern LED high-mast lights: The luminous efficacy of the complete fixture generally ranges from 120 to 180 lm/W, with high-quality products reaching over 200 lm/W (laboratory data). Efficacy depends on LED chip technology (e.g., flip-chip, COB packaging), driver efficiency, optical lens transmittance, and thermal management.
For example, by using Lumileds Luxeon or CREE XHP70 LED chips combined with a high-efficiency driver (efficiency >94%) and a PMMA lens (transmittance 92%), the complete fixture can easily achieve an efficacy of 150 lm/W.
When purchasing, it is important to distinguish between "LED chip efficacy" and "complete fixture efficacy." Some manufacturers may exaggerate by citing only the chip efficacy (e.g., 200 lm/W), while the actual fixture efficacy might be only 160 lm/W. You should request third-party integrating sphere test reports to verify the complete fixture's efficacy value. For high-mast lights—which operate for long periods daily—choosing high-efficacy products can significantly reduce energy consumption; although the initial cost is slightly higher, the long-term returns are substantial.
