WOODS HOLE, Mass. — Inside a laboratory at the Woods Hole Oceanographic Institution, thousands of glass vials hold sugar kelp gametophytes swirling under red light. The microscopic cells will grow into strains of fast‑growing seaweed that, through selective breeding, can produce up to three times the biomass of wild kelp. Their ultimate destination, scientists hope, is a biofuel refinery — not a salad plate.
“We need other sources of energy that are sustainable; we can’t just rely on petroleum,” said Scott Lindell, the marine scientist who runs the lab. “There’s hardly anything simpler, or anything that grows quite as fast and as sustainably, as seaweed.”
Kelp biofuel holds particular promise for ships and aircraft, which require liquid fuels dense enough to power long‑haul travel. Unlike electricity for cars, those sectors cannot easily plug into a battery grid. Through a pressurized, high‑heat process called hydrothermal liquefaction, kelp can be converted into a bio‑oil that burns with a lower greenhouse‑gas footprint than petroleum. Corn‑based ethanol already serves as a gasoline additive, but corn demands fresh water, agricultural land and pesticides. Kelp needs none of those — just ocean space and sunlight.
Yet the path to a commercial kelp‑to‑fuel industry is blocked by what researchers describe as a chicken‑and‑egg problem. Energy companies see no reason to build refineries for kelp oil until a steady, enormous supply exists. Farmers, in turn, will not scale up their operations without a guaranteed buyer. Oliver Dixon, a shellfish farmer in Point Judith, Rhode Island, supplements his oyster business by growing kelp each winter, harvesting about 10,000 pounds this month. Most of it goes to local restaurants and seafood markets. His 9‑acre farm is hundreds of times too small for biofuel production, and without a clear energy‑sector customer, he has no intention of expanding. “The buyers come in and out; it’s pretty discouraging,” Dixon said.
Government involvement has done little to break the cycle. In 2016 the Department of Energy launched the MARINER program — Macroalgae Research Inspiring Novel Energy Resources — which funded projects ranging from heat‑resistant kelp strains to whole‑genome studies. Lindell’s lab received six years of MARINER money to breed non‑reproductive kelp that would not interbreed with wild populations, making large‑scale farming safer. The funding ended in 2024 and has not been replaced. Federal research opportunities have become fewer and slower, Lindell said, even as the need for sustainable energy persists. “I don’t think things have changed incredibly since the first oil crisis,” he added, referring to a similar biofuels push launched in the 1970s that was abandoned when oil prices fell.
Even with dependable buyers, regulatory red tape would restrain expansion, according to Hauke Kite‑Powell, an engineer and economic analyst at Woods Hole. Most U.S. coastal waters are prioritized for recreation, fishing and conservation, making permits for large aquaculture projects hard to obtain. Dixon, for instance, cannot leave his farm infrastructure in the water year‑round; he must pull his lines and anchors each spring and reinstall them in the fall. Moving farms farther offshore could allow larger operations but would raise engineering costs and environmental questions — including the risk of entangling marine animals or depleting nutrients that wild species depend on. “We don’t yet have a full understanding of what all the ecological side effects of very large‑scale ocean farming might be,” Kite‑Powell said.
Some ocean‑farming advocates argue that fuel is the wrong goal for kelp in the first place. Bren Smith, co‑founder of the nonprofit GreenWave, contends that kelp’s immediate economic value — and its best chance to scale — lies in higher‑value products such as cosmetics, food and fertilizer, not in competing head‑to‑head with petroleum. “We’ve made this mistake before, right?” Smith said. “Competing with the most technically advanced, subsidized industry on the globe, the fossil fuel industry.”
Still, Lindell remains convinced that the arithmetic of finite oil will eventually tip the balance. His lab maintains more than 2,600 strains of sugar kelp collected across New England, a living library that he continues to breed and refine. “We’ll come to the realization that things have shifted in the marketplace,” he said, “and we can’t squeeze any more oil out of the earth in 30 years’ time.”