Most people think of seaweed as a tasty part of their spicy tuna roll or an unpleasant tangle at the beach, but in the future, seaweed may become a part of your daily commute.
The U.S. is striving to become a leading producer of seaweed for biofuel. The Department of Energy recently invested $22 million to begin developing the tools needed for large-scale seaweed production. The funds were distributed between 18 different projects grouped under the Macroalgae Research Inspiring Novel Energy Resources program, known as MARINER.
“With a growing population in the world and an increasing demand for food, we wanted to look for ways to minimize conflict between food and fuel,” MARINER director Marc von Keitz said. “And really, the only good large area to expand is into the ocean.”
Seaweed, or macroalgae as it is known to scientists, has several qualities that make it particularly suited to being used as a biofuel. Unlike traditional biofuel crops like soy or corn, seaweed does not take up land or water resources that could be used for growing food, and it doesn’t require added fertilizer—everything it needs is in the ocean. Under the right conditions, it also grows remarkably quickly, with some species growing up to two feet in a single day.
The projects funded by MARINER span all areas of production, from growth and harvesting to monitoring and even breeding better varieties of seaweed. They are trying to create innovative tools and technologies that would allow the U.S. to dramatically expand its ability to grow seaweed while also helping to minimize the costs.
“They’re starting to talk about economics of scale that hasn’t been seen before, with this grand goal of biofuel production. It’s only with that economy of scale that you begin to be able to have the price come down,” said Erin Fischell, a researcher at the Woods Hole Oceanographic Institute.
Today, most of the seaweed grown in the U.S. is used for food. Most production is done on small aqua-farms that are typically near the coast, where they can be protected from the rough conditions in the open ocean. “Historically these farms have been very manual labor intensive,” Fischell said. “People have had to drive out to them to check on them.”
Fischell and her group at the Woods Hole Oceanographic Institute received a portion of the MARINER funds to develop a system for monitoring seaweed farms in the open ocean using unmanned underwater vehicles (UUVs). The vehicles would be stationed at offshore farms long-term, monitoring the seaweed autonomously and relaying information back to shore.
The MARINER program is intended to jump-start the development process for large-scale seaweed farming, but private investors or other grants will need to take over once the three-year program ends. For people to consider investing private funds, seaweed-based biofuel has to be economically feasible. If it’s too expensive to produce, it won’t be able to compete with other fuels on the market.
MARINER’s cultivation and harvesting projects have a concrete financial goal to meet: a dry metric ton of seaweed should cost no more than $80 to produce. According to Michael Heussman, project leader for a group working out of the Marine Sciences Laboratory in Sequim, Washington, projects that cannot get their estimated costs to this level will not be funded after the first year.
“This is going to be tough,” Heussman said. “That’s why it has to be a simple system. You can’t have a complex system and meet this target.” His project received $500,000 for the first year to design a free-floating seaweed farm that would follow nutrient-rich currents in the open ocean.
The day when you’ll be pouring seaweed into your gas tank is still a long way off—if it arrives at all—but with the MARINER projects, researchers hope to make that future just a little more likely.
“I think it’s definitely doable, but it will not happen in the next five years,” von Keitz, said. “This is something that will probably take ten, 15, 20 years at least to get there.”