Effects of Flashing Light-Emitting Diodes on Algal Biomass Productivity


To reduce power consumption and enhance algal biomass productivity in a thin flat-plate bioreactor (called a sliver tank bioreactor), flashing (pulsing) light was used. Biomass productivity and power consumption were monitored in controlled experiments using various photon flux levels, including a constant (non-flashing) flux of 75 µmol photons m-2 s-1 and three flashing experiments with photon fluxes of 375, 275, and 175 µmol photons m-2 s-1. Flashing experiments were performed at 10 kHz and a duty cycle of 20 %. A sliver tank bioreactor with a chamber width of 6.4 mm was used for its short optical path. Data from the experiments where light was flashed with a photon flux of 375 µmol photons m-2 s-1 indicated 9.6 % less power and 2.86 times the biomass productivity compared to the constant photon flux experiments. Similar results were obtained for the other flashing light regimes, which had lower biomass yields but also less input power per unit biomass produced, indicating that a large fraction of the continuously applied photons are shed or wasted, even at levels approximately 1/30th the intensity of full sun.


Mechanical and Aerospace Engineering

Keywords and Phrases

Flashing Light Effect; Input Power; Light-Emitting Diodes; Productivity; Scenedesmus Dimorphus; Turbidity

International Standard Serial Number (ISSN)

0921-8971; 1573-5176

Document Type

Article - Journal

Document Version


File Type





© 2013 Springer Science, All rights reserved.

Publication Date

22 May 2013