Microalgae are a promising source of high-value products (i.e. carotenoids, ω-3 fatty acids), as well as feedstocks for food, bulk chemicals and biofuels. Industrial production is, however, still limited because the technology needs further development. One of the main bottlenecks is the low efficiency of sunlight usage -the main substrate for growth- achieved under outdoor conditions.
Locations with high irradiances, and moderate temperatures, along the year are considered optimal for microalgae production. However, an excess of sunlight can also be negative and the cells can be damaged. Under these conditions, the resulting photosynthetic efficiency is low, leading to a low biomass productivity. In this sense, maximization of photosynthetic efficiency in areas with much sunlight is required for commercial purposes. In this Thesis, the effects of simulated winter and summer sunlight conditions on the production of microalgae are evaluated. It is proven that photosynthetic efficiency can be highly improved via the light dilution effect. The injurious effects of excessive light are minimized and/or avoided since a lower amount of light is received per cell when photobioreactors are placed vertically. The production of microalgae in locations with much sunlight should be thus considered.