Luminostat operation: A tool to maximize microalgae photosynthetic efficiency in photobioreactors during the daily light cycle?

► A vertical luminostat photobioreactor allows for efficient growth outdoors. ► A maximal biomass yield of 1.27 g of biomass per mol of photons supplied was found. ► A strict luminostat regime could not be maintained under varying light conditions. ► Luminostat operation under outdoor conditions has to be further modified.