A word of caution with any biofuel production as an alternative to fossil fuel or electricity. The cost (and energy use, which is widely referred to as 'parasitic energy') of construction and maintenance (e.g. CO2 injection, cleaning and sterilisation of bioreactors, algal culture maintenance and inoculation etc.) of photobioreactors (PBRs), filtration or isolation of algae, drying, lipid extraction and process have to be estimated carefully to ensure sustainability.
PBRs can also be used to produce high value algae (cosmetic or health beneficial that can produce beta-carotene or astaxanthin) which may be more sustainable than biofuel production under the current low global fossil fuel market.