What is it?
Technically, it is called macroalgae (as opposed to the microalgae that grows in ponds). To the bioenergy field, it is aquatic biomass. More commonly it is known as seaweed. Red, green, and the fast-growing brown seaweed with its large, leaf-like fronds, are drawing attention.
Why is it of interest?
The resource potential of macroalgae as an energy feedstock is estimated to exceed that of all terrestrial biomass by about three-fold, according to a study cited in an
analysis by the Pacific Northwest National Laboratory for the Department of Energy.
Where does it grow?
In coastal waters around the world.
Why does it matter?
In addition to being highly productive, it does not require fresh water or land so it does not compete with food production.
Understanding how to harness seaweed will require research
and development into macroalgae cultivation at large scale, harvesting, transporting, and conversion to fuel. One challenge with seaweed is that it produces sugars, including alginate, that can be difficult for microbes to digest.
Who is working on it?
Bio Architecture Lab, a company based in California, is one leader in the field. In a paper published in Science this year, researchers there reported using an E. coli strain to break down the alginate in brown seaweed and then engineering the strain to convert the sugars directly into ethanol. A pilot plant to demonstrate the feasibility of the process is being built in Chile, said the company.