
Bengaluru-based startup Sea6 Energy, which has raised more than $22 million so far, aims to produce enough biomass to substitute for India’s entire oil imports, according to its co-founder.
If the ocean farming startup can grow enough seaweed around India’s coastline to make the required biomass, it can achieve the goal and rid the country of its significant dependence on crude oil imports.
India’s Exclusive Economic Zone (EEZ) – an area beyond and adjacent to its territorial waters – spans 3.2 million square kilometres (sq km). With a 7,500-km coastline, India has exclusive control over the resources of its EEZ, whose limit is 200 nautical miles from the baseline.
“Our calculations indicate that to farm enough seaweed and grow enough biomass, which can be converted into biofuel to satisfy all of India’s needs, we need only a tiny fraction of the EEZ, about 120,000 sq km. It’s entirely feasible, but we need to develop policies as a country for that,” Shrikumar Suryanarayan, co-founder and chairman of Sea6 Energy, which recently raised $18.5 million in its Series B funding round from
BASF Venture Capital and Netherlands-based aquaculture fund Aqua-Spark.
Ocean farming, a way of trapping most of the Sun’s energy that falls on oceans, can help generate large amounts of biomass to make biofuel sustainably without taking out the biomass used for food and feed purposes.
“Today, we can make biofuels from biomass but if made at a very large scale, it will impact the food chain. It’s a unique solution but also a long haul,” Suryanarayan told.
Though there are companies trying to grow seaweed in the temperate regions, Sea6 Energy is the only vertically integrated player thinking of an end-to-end solution, he said.
Large oil companies such as ExxonMobil, Shell, Chevron, and
Reliance has tried growing microalgae – which are not the same as seaweed and grown on land – that require sizable investments.
“They’re not very scalable. So, everybody burnt their fingers on that. This is a very different technology,” he said, adding that its technology works in the open seas as well as deep oceans.
Until now, there was no technological solution to carry out farming in the open oceans. The technology to grow tropical seaweeds throughout the year had been restricted to shallow and calm waters near the coast and was a labor-intensive process.
“We have figured out ways to grow seaweed in the open ocean so that depth and sea area is no longer a constraint. We have also automated the whole process. We have invented the equivalent of sea tractors which make large-scale farming on the sea possible,” he said.
Seaweeds have a short growth cycle of six weeks, so they can be planted every day and harvested after six weeks.
India imports 215 million tonnes of crude oil a year and the amount of biomass needed to produce all this oil from biomass is over a billion tonnes. For producing one kilogram of crude oil, four to five kilograms of biomass are required.
To put this figure in perspective, the entire agricultural output of India is less than a billion tonnes.
So, not only is there not enough biomass to substitute for crude oil imports, but even if one were to start diverting significant fractions of it, there would not be enough food to feed the people of the country.
“This has held up the scalability of biofuel, but if we can carry out farming on the sea, then we are sidestepping this limitation,” he said. “Then land can be used to grow food for our burgeoning population and the sea area can be used to grow plants that can be converted into biofuel.”
The idea was conceived in 2010 but it took about a decade by the time the technology was developed, and patents were filed. Sea6 Energy is looking at another six years before it can completely develop the required technology.
The technical feasibility of converting seaweed to biofuel has been demonstrated and has been scientifically published by IIT-Madras.
However, only when the seaweed is grown at a large scale does its price come down enough for biofuel rates to be profitable.
“One needs to build small farms before building large ones. Though the price of seaweed is high, the company has come up with other products that can be made with it to de-risk the entire process,” Suryanarayan explained.

Sea6 Energy has developed a novel extract from seaweed that can be used for agriculture and is exporting it all over the world. “This is increasing crop yield by 30%. This extract basically improves fertilizer use efficiency,” he said.
The company can sell this product and make money and it also helps pay for research and development costs of improving farm technology constantly and scale up farms.
As the price of seaweed keeps dropping, it can open up newer markets.
The company is expecting a reduction in seaweed prices to a point where biodegradable plastic produced from seaweed becomes a reality by 2025. “We should be within sight of biofuels by 2028,” Suryanarayan said.
Some countries are ahead of others.
Indonesia has a good variety of seaweed and has a history of seaweed cultivation. It is a more aqua culture-invested country, so the government has already drafted policies to lease out the sea for shrimp farming or oyster farming or offshore fish culture.
“In India, we are still developing such policies,” he said.
The company does all its ocean farming off the coast of Tamil Nadu all the way from Kanyakumari in the south to beyond Rameswaram. It works with fishermen, gives them the know-how and then buys back the seaweed.
Sea6 Energy is currently based at the Centre for Cellular and Molecular Platforms (C-Camp), the Bengaluru-based biotech incubator built by the Department of Biotechnology (DBT).
C-Camp chief executive Taslimarif Saiyed told ET the obstacle to Sea6 Energy’s vision is economic viability.
“Scalability is a problem because to beat petroleum production one needs to produce thousands of gallons of biofuel… Hopefully, more companies will come forward to develop affordable technologies to develop algae biomass into biofuel. The technology that can convert algae to biofuel has to be able to do it at a lower cost compared to the price of petroleum,” Saiyed said.
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