PRINCIPLES FOR EFFICIENT UTILIZATION OF LIGHT FOR MASS-PRODUCTION OF PHOTOAUTOTROPHIC MICROORGANISMS

Outdoor production of microalgae could be set on a sound industrial ba sis if solar energy were utilized at a much higher efficiency than pre sently obtained. Many types of photobioreactors have been developed in the past in an attempt to answer this challenge, but their photosynth etic efficiency has been rather similar to the basically inefficient o pen raceway commonly used today. Efficient utilization of the oversatu rating solar energy flux mandates that reactors should have a narrow l ightpath to facilitate ultra-high cell densities, be maximally exposed to sunshine, and have an efficient mixing system to create strong tur bulent streaming to affect dark-light cycles of the highest possible f requency.