Various forms of biomass, biofuel and biogas production are already in operation: wood waste, ethanol from sugar cane, primary wood (willow, poplar, pine), miscanthus, anaerobic digestion of organic waste, and so on.
Is it possible to carry out large-scale seaweed cultivation for biomass / biofuel production at sea, or are the technical / economic / regulatory barriers that make it much harder, relative to land-based biomass production?