Thirty feet below the ocean’s surface, a revolution is underway. Ocean sensors—vital for measuring water conditions and tracking changes in the marine environment—are stuck in a high-cost, high-risk cycle of battery replacement. But what if these devices could power themselves using the ocean’s own resources?
That’s what Ruggero Rossi, assistant professor of environmental health and engineering, is working on: generating electricity from the seawater’s microscopic biomass by turning dissolved organic matter, plankton, and algae into energy that could power the sensors while reducing their cost and reliance on traditional energy sources.
“This is a complicated project. Nothing similar has been attempted before,” says Rossi, who previously scaled up a device to convert organic waste into electricity, but in accessible wastewater treatment plants, not under 30 feet of seawater.
The upgraded sensor design will consist of three parts: a filter, similar to fish gills, to collect biomass; a fermenter to break it down into organic acids; and a microbial fuel cell to transform those acids into electricity.
Rossi’s team is working on the fuel cell reactor, optimizing energy output. The goal is to generate 0.01 kW of energy—enough to charge a cell phone—while maintaining its current weight and size.
“If we can optimize this process, the possibilities are as vast as the ocean itself.” — Roggero Rossi
Precise placement is key for effective testing, Rossi says. Too deep, and the cell lacks oxygen; too shallow, and it lacks biomass. The first prototype will be deployed off the coast of Lewes, Delaware.
While the proposed cell design has no precedent in any project of this scale, Rossi is optimistic about the cell’s potential. “If we can optimize this process, the possibilities are as vast as the ocean itself,” he says. Researchers from James Madison University, Harvard, the University of Maryland, the University of Delaware, and private industry are partners in the two-year effort with support from the Defense Advanced Research Projects Agency.