A new report by Bellona Foundation explores the potential and challenges of using seaweed biofuels in aviation. The report Opportunities and Risks of Seaweed Biofuels in Aviation provides comprehensive recommendations for researchers, public authorities and consumers. The report finds that that the use of seaweed biofuel can unlock great potentials, while addressing many of the challenges associated with conventional biofuels. Seaweed is a large, diverse group of aquatic plants. Compared with, for example soya, which is also used for the production of biofuels, growing seaweed is faster, more space-efficient and does not require the use of fresh water or the addition of fertilizer. Furthermore, seaweed does not compete for land area. On the contrary, seaweed can be grown in exactly the area we have the most of: the sea. The report acknowledges that biofuels are necessary to decarbonise parts of the economy, and that climate science shows that fighting climate change will necessarily involve bioenergy, though the sustainable scale remains one of climate science’s most unsure areas.
In combination with fish farming: When cultivation of seaweed is located in proximity to fish farms, seaweed can use the excess, otherwise wasted, nutrients and thereby ensure recycling and cleaning of the surrounding waters, which may otherwise suffer from over-supply of nutrients. It has been documented that kelp can remove between 30-100% of dissolved nitrogen produced by fish farming (Leonczek, 2013).
In combination with CCS: Seaweed biofuels in combination with carbon capture and storage (BECCS/Bio-CCS) holds the potential to deliver negative emissions, removing excess CO2from the atmosphere over time. Carbon capture can be done at a biorefining facility that makes biofuels from seaweed or at a facility that combusts the seaweed directly for heat and power.
There are challenges when it comes to preservation and storage methods, which have a large impact on which end-products will be available. However, the main challenges to a wide deployment of marine biofuels are not technical, but commercial and political. The goal must therefore be to implement incentives, reduce costs and to increase the profitability of seaweed production for energy purposes.