By: Due Diligence Horticulture

March 28, 2025

Introduction

Light is both a critical driver of plant growth and a major contribution to operational costs in controlled environment  agriculture (CEA). High-efficiency LEDs have already transformed modern cultivation by reducing energy use and  improving light uniformity, but we are approaching an upper limit for improving fixture efficacy[1]. For this reason,  researchers and growers alike continue to seek novel lighting strategies for reducing energy use while maintaining  productivity. Pulsed LED lighting has emerged as a promising strategy for improving the economics and  sustainability of CEA. By delivering light in rapid on–off cycles, imperceptible to the human eye, pulsed lighting can significantly lower energy use while maintaining—or potentially improving—plant growth, photosynthetic  efficiency, and nutritional quality compared to continuous lighting. Below is a concise overview of recent findings on the impacts of pulsed LED lighting. 

Energy Use Efficiency

Pulsing reduces the time lights actively draw current, thus lowering overall electricity consumption. Reported  energy savings of 10–40% exist when frequency, duty cycle, and driver design are carefully aligned with crop  needs[2,3]. However, setup complexity and hardware costs must be weighed against potential efficiency gains.

Growth and Yield

Lettuce and other crops grown under pulsed LEDs can match or exceed the growth achieved under continuous lighting if the daily light integral (DLI) is maintained[2–4] (Figure 1). In some cases, pulsed treatments increased fresh and dry weight by up to 30% while preserving or improving crop quality[2,4].

graph showing that pulsed LED lighting can achieve the same DLI as continuous lighting

Photosynthetic Efficiency

High-frequency pulses can supply photons in short  bursts that photosynthetic reaction centers use  effectively. Some studies show similar or slightly improved net assimilation under pulsed conditions by adequately saturating the photosystems while avoiding photoinhibition[2,5].

Morphological Responses (Leaf Area)

Increased leaf expansion has been documented in lettuce under pulsed, multispectral LEDs4 (Figure 2). By  increasing leaf area, plants capture more photons, which can indirectly drive greater biomass accumulation even  if photosynthetic efficiency itself remains unchanged.

graphs showing that pulsed LED lighting can increase fresh and dry weight by increasing leaf area

 

Quality & Nutritional Factors

Improvements in chlorophyll content,  antioxidant levels, and phenolic compounds  have been observed in lettuce and other leafy  greens grown under pulsed LEDs[2,4] (Figure 3).  This suggests pulsing may offer value in  enhancing both marketable appearance and  health-promoting compounds.

graph showing that pulsed LED lighting can increase chlorophyll, carotenoids, and antioxidants

Practical Implications for Growers

  • Balancing Complexity and Cost:  Pulsed LED lighting often involves  specialized drivers and controls. While  potential energy savings are  promising, growers must analyze whether the savings justify the added hardware and system complexity.
  • Crop-Specific Optimization: Pulse frequencies and duty cycles that benefit lettuce, for example,  may not necessarily translate to tomatoes or cannabis. Each crop may require specific tuning, and  some may respond less favorably to pulsing. 
  • Minimizing Heat Load: Pulsed LED lighting can reduce heat load compared to continuous lighting,  reducing the need for HVAC/cooling infrastructure. However, this should be confirmed through direct  measurement, as this depends on both “on-phase” intensity and environmental conditions. 
  • Quality and Market Value: For crops sold fresh, like lettuce, improvements in leaf color, texture, or  nutrient content can add market value that justifies up-front investment.

Conclusion

Pulsed LED lighting holds promise for enhanced energy efficiency while maintaining productivity and product  quality in controlled-environment agriculture. As research continues to explore pulse frequencies, duty cycles, and  species-specific responses, the practical potential for pulsed lighting in CEA should become more clear. For now,  its most certain benefit lies in energy-use reduction, with encouraging but variable impacts on growth and quality.

 

References 

  1. Kusuma, P., Pattison, P. M. & Bugbee, B. From physics to fixtures to food: current and potential LED  efficacy. Horticulture Research 7, 1–9 (2020). 
  2. Carotti, L. et al. Pulsed LED Light: Exploring the Balance between Energy Use and Nutraceutical Properties  in Indoor-Grown Lettuce. Agronomy 11, 1106 (2021). 
  3. Olvera-Gonzalez, E. et al. Pulsed LED-Lighting as an Alternative Energy Savings Technique for Vertical  Farms and Plant Factories. Energies 14, 1603 (2021). 
  4. Miliauskienė, J., Karlicek, R. F. & Kolmos, E. Effect of Multispectral Pulsed Light-Emitting Diodes on the  Growth, Photosynthetic and Antioxidant Response of Baby Leaf Lettuce (Lactuca sativa L.). Plants 10, 762  (2021).
  5. Tennessen, D. J., Bula, R. J. & Sharkey, T. D. Efficiency of photosynthesis in continuous and pulsed light  emitting diode irradiation. Photosynth Res 44, 261–269 (1995).