Seaweed Biofuel: A rocky road

Biofuels  provide a  renewable, alternative source for energy. Made from organic matter or waste, they play a key role in reducing carbon dioxide emissions. In fact, biofuels are of great value in decarbonising industries, such as aviation, where electrification is not yet available. 

While crops or wood tend to be commonly associated with biofuels, there might be another promising source for the development of renewable energy: Seaweed. 

How so?

Among the many reasons that make seaweed such a potential source for biofuel, you’ll find the following: 

Availability: Unlike more conventional sources for biofuels, seaweed does not compete for land space. Forests do not need to be cleared up to cultivate it, because it grows in what we have the most: oceans. 

Scalability: Seaweed can grow straight, on circular ropes, horizontally or vertically underwater at 10m depth. Also, it can be grown in integrated solutions that bring together other sea production, like fish farming and offshore energy. 

Productivity: The carbohydrate content of seaweed, about 50% of dry mass, can be processed into biofuel for cars, trucks and airplanes. In fact, when compared to soybeans -another biofuel source-, seaweed can yield up to 30 times more energy per acre. 

Responsibility: It is space efficient, it does not require fresh water or additional fertilizers, and it captures CO2 from the environment as it grows. 

However, pushing seaweed into this sector comes with many challenges

Cascading use of biomass: This concept entails processing a natural resource into products that can be reused and recycled. It aims to employ the resource for higher value uses before utilizing it only for energy purposes. Burning it would result in the loss of useful raw material. On this note, besides biofuel, seaweed can be used for food, fertilizers, animal feed, medicine, plastics, cosmetics and textiles. Thus, value chains need to be carefully developed to safeguard and prioritize the many uses of seaweed. 

Business case: the current business case for seaweed biofuel is very weak. The biofuel output compared to the input costs do not make it a compelling case at all even though the planet could use an alternative to fossil fuels.   

But at the end of the day, the versatility and competency of seaweed is once again proven even though in the line of biofuels, the road seems to be rockier. At the moment.