Algae biofuels – a potential lifeline?

Despite my seemingly pessimistic assessment on the scalability of existing biofuels, hope remains for the sector is not yet lost! Algae feedstocks may offer an avenue to circumvent the inherent downsides of terrestrial agriculture, with its projected yield per unit area exceeding that of edible oil crops. The video below focuses on biodiesel production from microalgae, but remains helpful as an overview.

Utilization as biofuels are only the tip of the iceberg where environmental benefits of microalgae are concerned. Other potential applications range from carbon fixation when cultivated near sources of CO2 emissions to bioremediation of municipal, agricultural, and industrial wastewaters, the latter of which also serves to reduce water and fertilizer inputs required for microalgae growth. Unfortunately, the poor commercial viability of microalgae presents a significant shortcoming. A study was conducted in 2014 to assess affordability of different biofuel feedstocks per gigajoule of energy output, which found that production costs for microalgae at US$13–8949/GJ significantly exceeded its second-generation lignocellulose counterpart at US$19–62/GJ.

Genetic engineering of algae into a fourth-generation biofuel into higher-yield varieties seems a logical means of improving its price-competitiveness, but brings potential risks of modifying ecosystems as invasive species if accidentally released into the wild. Although pilot testing thus far indicates that genetically engineered algae is outcompeted by native varieties outside controlled settings, scepticism is bound to remain. Nonetheless, the lack of better alternatives convinces me that making this leap of faith is a practical necessity.