From Ocean to Octane: How Seaweed is Powering a Greener Tomorrow
When you think of seaweed, your mind probably drifts to sushi rolls, tangled toes at the beach, or perhaps that mysterious green goo in your toothpaste. But beneath its slippery surface lies an untapped powerhouse—a marine marvel that could be the unlikely hero in our quest for sustainable energy.
Enter Sea6 Energy, a Bengaluru-based startup that’s rewriting the story of seaweed—taking it from sea to spark plug.
The Startup That Started at Sea (and IIT Madras)
Back in 2010, a group of visionary IIT Madras alumni—Nelson Vadassery, Shrikumar Suryanarayan, Sri Sailaja Nori, and Sowmya Balendiran—looked at seaweed and saw more than a salad garnish. They saw fuel. They saw fertiliser. They saw the future.
What started as a focus on microalgae soon evolved into a full-blown love affair with macroalgae—specifically, fast-growing red seaweeds. Why? Because they’re scalable, economically viable, and they grow faster than a college rumor—up to two feet a day!
Farming the Future: Cultivating the Blue-Green Gold
But this isn’t your average algae-in-a-jar setup. Sea6 Energy developed a mechanised ocean farming system, designed to cultivate seaweed at industrial scale. Think of it as vertical farming, but horizontal and underwater—a graceful dance of green ribbons swaying beneath the sea, quietly capturing carbon while they grow.
This isn’t just farming. It’s farming 2.0, and it’s renewable, reliable, and remarkably green.
Turning Seaweed into Biofuel: Nature’s Alchemy
So, how exactly does something slimy become something that fuels jets and heats homes?
Through a process called hydrothermal liquefaction (HTL). Sea6 Energy takes wet seaweed biomass and subjects it to high heat and pressure, simulating what the Earth naturally does over millions of years—but in mere hours. The result? Biocrude—a thick, energy-rich oil comparable to conventional crude.
And here’s the kicker: this process is carbon neutral. The CO₂ released when the fuel burns is offset by the CO₂ the seaweed absorbed while growing. It’s a neat loop of give-and-take—a rare win-win in a world of climate trade-offs.
Big Players, Big Moves
The startup’s trailblazing work has drawn global eyes and serious investment. In 2021, Sea6 Energy landed a $9 million funding round from Aqua-Spark, a Netherlands-based investment firm that clearly sees the tide turning in seaweed’s favor.
By December 2024, Sea6 had levelled up again, entering into a partnership with Hindustan Petroleum Corporation Ltd (HPCL). The mission? To co-develop seaweed-to-fuel technologies that could help meet India’s ambitious energy targets outlined in the National Biofuel Policy.
A Green Revolution That Grows Underwater
The potential impact is enormous. Seaweed doesn’t compete for arable land or freshwater, making it a hero in a world of strained resources. Large-scale cultivation boosts marine biodiversity and acts as a carbon sink, turning vast stretches of ocean into eco-allies.
And since it grows so rapidly, it doesn’t just sit there—it hustles. Seaweed is the startup founder of the ocean world: lean, green, and endlessly scaling.
The Bottom Line: Seaweed is More Than Salad
Sea6 Energy isn’t just innovating—they’re proving that sustainability can be scalable, and that the answers to our biggest problems might be swaying gently beneath the waves.
From ocean farms to filling stations, this humble marine plant could soon be fuelling your morning commute and cooling our planet all at once.
Who knew the future smelled faintly of saltwater and sushi?