An automated ‘sea combine’ for harvesting seaweed at scale

An Indian company is developing automated technology that makes growing seaweed at scale much less labour intensive

Spotted: There has been an explosion of interest in seaweed recently. And no wonder – it grows quickly, requires no additional resources, is very good at sequestering carbon and has a wide number of uses, from food to energy production. However, the process of seaweed farming can be fairly labour intensive. Now, Indian company Sea6 Energy has developed an easier way to farm seaweed, using an automated “sea combine”. 

The traditional method for growing seaweed is to attach pieces of seaweed to rope lines or nets by hand, wait for it to grow, and then manually harvest and “re-seed” the lines. Sea6 Energy uses a different approach. The start-up has established a series of floating seaweed farms off the coast of Bali, Indonesia. The seaweed is attached to rope lines, as in traditional farming, but the sea combine, which resembles a large catamaran without sails, travels back and forth through the lines, harvesting and replanting the seaweed automatically. 

Sea6’s technology is designed to allow seaweed farming to scale up – a necessary precursor to the wide-scale use of seaweed as a biofuel. Seaweed farming also avoids many of the sustainability issues involved in land-based agriculture—there is no need for irrigation or fertiliser, and the seaweed grows incredibly rapidly – as much as two feet a day. 

Sea6 founder Shrikumar Suryanarayan hopes that by using automation to scale up seaweed farming, he can reduce the cost of production to the point where the seaweed can be used as a biofuel. Biofuel has not been seen as a viable replacement for crude oil because of the massive amount of plant biomass required – which would disrupt the food supply. Suryanarayan points out that, “There was no feasible way to produce [biofuel] without disrupting the food supply. Seaweed, grown in the ocean, wouldn’t have the same problem. It just needed to be cheaper to produce.” 

Sea6 is not the only company working towards using seaweed in biofuels. Springwise recently covered a new method for growing kelp in the open ocean – since most seaweed only grows close to shore, this could be a real game-changer. Other seaweed-based innovations include a kelp-based hamburger and seaweed-based bio-packaging.