Scientists are looking to expand the options when it comes to clean energy. With wind and solar power sources already being developed, Japanese researchers are looking at another possibility: sea energy.
Dr. Tsumoru Shintake, a professor at the Okinawa Institute of Science and Technology’s Graduate University, began looking into new ways to harness the ocean’s power in 2012.
He and the university’s Quantum Wave Microscopy Unit anchored turbines to the ocean floor in the Kuroshio current, a north-flowing ocean current off the coast of Japan. The turbines were anchored with mooring cables that turned the current’s energy into electrical power.
The experiment, titled “Sea Horse,” was a success, and the team is now looking for industry sponsors who will help them move onto the next phase of the project.
“Particularly in Japan, if you go around the beach you’ll find many tetrapods,” Shintake said in a press release. “Surprisingly, 30 percent of the seashore in mainland Japan is covered with tetrapods and wave breakers.”
Tetrapods – concrete, pyramid-shaped structures that help soften the force of waves along the shore – and the beach walls dubbed wave breakers could be altered to serve a dual purpose, Shintake and his team said. “Intelligent” tetrapods and wavebreakers with nearby turbines could both protect Japan’s shoreline and turn sea energy into electricity for nearby communities.
“Using just 1 percent of the seashore of mainland Japan can [generate] about 10 gigawatts, which is equivalent to 10 nuclear power plants,” Shintake said. “That’s huge.”
To test the theory, the team has already placed some turbines near tetrapods and coral reefs, dubbed the Wave Energy Converter.
The turbines have been designed with Japan’s environment in mind. They’re built strong enough to withstand typhoons, and flexible so the currents and waves don’t destroy them, the scientists said. They’ve also been designed so that sea creatures can avoid their blades.
They plan to install half-scale models of the new turbines soon. If successful, the project could be copied in other places where strong ocean currents might provide clean sea energy.
Shintake and his team presented their project at the 3rd Asian Wave and Tidal Energy Conference.