The U.S. Department of Energy announced grants for The University of Southern Mississippi (USM) totaling $1 million to be used for researching the use of seaweed to produce energy.

DOE’s Advanced Research Projects Agency-Energy (ARPA-E) approved $500,000 for research on an adjustable-depth seaweed growth system called AdjustaDepth and an additional $500,000 to develop a seaweed ranching paddock.

“We are excited to be a part of this effort to develop novel energy solutions utilizing ocean-based technologies in the Gulf of Mexico,” said Dr. Gordon Cannon, USM vice president for research. “The project dovetails nicely with the inauguration of USM’s Ocean Engineering degree program, and the projects as a whole certainly fit well in the wheelhouse of our School of Ocean Science & Engineering.”

ARPA-E awarded the grants through the Macroalgae Research Inspiring Novel Energy Resources (MARINER) program, which explores ways to harness marine biomass for fuel and other uses. ARPA-E awarded USM grants for “Design & Experimental Deployment of Integrated Cultivation & Harvesting Systems.”

USM’s AdjustaDepth team will develop a novel and robust seaweed growth system capable of precise depth positioning for maximizing productivity and avoidance of surface hazards such as weather or marine traffic. The system is anticipated to be suitable for diverse “attached-growth” seaweeds and will be scalable across tropical and temperate climate regions.

“From Alaska to the Gulf Coast, the U.S. has offshore resources capable of producing enough seaweed to handle as much as 10% of our demand for transportation fuel,” ARPA-E acting director Eric Rohlfing said. “By focusing on the technological challenges to growing and harvesting macroalgae efficiently and cost-effectively, MARINER project teams are building the tools we need to fully put this resource to work, contributing to our energy future.”

The primary features of AdjustaDepth are that it works in any climate or location with native seaweed, maintains precise depth control between the optimal growing depth and storm avoidance depth, utilizes underwater glider operation and provides an easy transition from manual to fully automated operation and harvesting, USM said. The structure’s minute-to-minute optimizing depth for maximum light intensity and minimum wave impact makes the entire system much less expensive than structures that remain on or near the surface during storms.

Dr. Reg Blaylock, assistant director for Thad Cochran Marine Aquaculture Research Center, is the principal investigator for SeaweedPaddock, a floating, semi-autonomous, renewably powered, moveable enclosure for ranching seaweed. The team includes research scientists and engineers from Ocean Foresters, the University of New Hampshire, Liquid Robotics, Texas A&M University and numerous other researchers and advisers.

The SeaweedPaddock will encircle an area of ocean containing free-floating Sargassum mats with a floating SeaFence and use remotely operated tugs called Wavegliders to manage the enclosure and move it to avoid ships and storms or find areas with high nutrient levels. The system is designed to operate over the course of a year without returning to shore and can potentially produce more than 100,000 tons of seaweed.

“This ARPA-E project offers a unique opportunity to work with a great team of research scientists and engineers to advance aquaculture, aid biofuel production, create consumable products and provide innovative systems designs,” said Dr. Kelly Lucas, director of the Thad Cochran Marine Aquaculture Research Center at USM. “We are happy to be selected to continue developing the AdjustaDepth design and work with other selected teams to advance macroalgae production in the U.S.”