Relationship Between Energy Efficiency and Color Consistency in LED Lighting

This study presents the first comprehensive investigation establishing the relationship between color consistency and luminous efficacy of radiation (LER) in phosphor-converted light-emitting diodes (LEDs), introducing novel selection criteria for energy-efficient applications. A systematic analysis of LED sources with nominal correlated color temperature (CCT) values of 3000 K and 4000 K across color-rendering index (CRI Ra) thresholds (≥60 and ≥80) was conducted, evaluating spectral power distributions (SPD) and chromaticities relative to 3-step, 5-step color-consistency circles, and 7-step American National Standards Institute (ANSI) quadrangles. Novel findings reveal a previously uncharacterized strong positive correlation between color consistency and luminous efficacy across all analyzed LED sources. LEDs with chromaticities within 3-step color-consistency circles consistently demonstrated superior LER values compared to 5-step boundaries, while sources outside established circles showed significantly inferior energy performance despite meeting nominal CCT requirements. The research establishes that tighter color-consistency tolerances directly correlate with enhanced luminous efficacy, revealing an intrinsic relationship between color quality and energy performance. These breakthrough findings introduce a paradigm shift in LED selection methodology, providing lighting professionals with evidence-based criteria that simultaneously optimize color consistency and energy efficiency, enabling more sustainable lighting solutions through integrated quality–performance assessment.