Sustainability: fast-growing, easily utilised marine algae
A potential solution to the global problems associated with growing agricultural crops for fuel (for example increased food costs, threats to conservation land and increasing freshwater demand) is to cultivate aquatic plants instead.
The oceans cover more than 70% of the world’s surface and their extensive coastal regions are more efficient for growing biomass than the land. The marine environment therefore offers the planet’s largest area for cultivating biomass and opportunities are already being realised in countries like China.
All plants use photosynthesis to convert sunlight energy into chemicals, particularly sugars, which are then converted within the plants into more complex organic molecules including lipids (oils).
Microalgae are one of the planet’s most promising sources of renewable biomass. They exist as unicells, colonies and long filaments, and can grow in a wide variety of conditions – from freshwater to extreme salinity. They are more efficient converters of solar energy than terrestrial plants and take carbon dioxide out of the atmosphere as they grow.
Macroalgae, or seaweeds, are also highly efficient at converting solar energy into biomass and their simple internal structure makes them a better material than land plants for complete biological degradation.