Microalgal Biomass for Bioenergy Applications - Chapter 2: Microalgal based biofuels: Sources, benefits, and constraints

Elsevier, Microalgal Biomass for Bioenergy Applications, pages 23-40
Patrick Moriarty, Damon Honnery

Algae are not presently being used as a feedstock for commercial production of energy; any large-scale production lies in the future, possibly decades away. It follows that the prospects for algae-based fuels must be evaluated in the context of the future world energy situation. Future energy use faces at least two challenges. The first is ongoing climate change, which demands a strong and prompt response. The second is fossil fuel depletion should its use continue at current or higher annual levels. Microalgae-based fuels have the potential to address both challenges, but they must compete with other sources of non-carbon energy. Among the advantages of microalgae for fuel are its rapid growth and the fact that it does not need the vast land areas that conventional biomass production requires. Its disadvantages include its current high unit costs for fuel and its low energy return on energy invested. The future for this innovative fuel is hard to predict, depending on technical advances and cost reductions of it and competitor fuels. The decision to phase out internal combustion engine vehicles in a decade or two means that algae fuels will need to look at other markets.