A new type of turbine designed at Japan’s Okinawa Institute of Science and Technology (OIST) could generate electricity while simultaneously protecting coastlines from erosion.
(Credit: OIST)
The Wave Energy Converter (WEC) project involves using multiple turbines near the shoreline, which harvest the energy of crashing waves. Like the concrete tetrapods and wave breakers used on coasts around the world, the turbines would help dissipate the incoming power of the ocean, helping to limit erosion.
“Surprisingly, 30 per cent of the seashore in mainland Japan is covered with tetrapods and wave breakers,” said OIST’s Professor Tsumoru Shintake, who is leading the project.
“Using just 1 per cent of the seashore of mainland Japan can [generate] about 10 gigawatts [of energy], which is equivalent to 10 nuclear power plants. That’s huge.”
According to the researchers, the devices will be able to withstand the harsh wave conditions as well as extreme weather such as typhoons. Inspired by dolphin fins, the five blades on the 70cm diameter turbines are flexible, as is the supporting structure, which will allow the entire mechanism to “bend like a flower”. The flexible blades will also be calibrated to rotate at speeds that are not dangerous to marine life. Behind the blades, a permanent magnet electric generator is housed in a watertight ceramic casing, while energy is returned ashore via a cable in the anchoring structure.
(Credit: OIST)
The OIST team believes the turbines could operate in locations where tetrapods have already been placed, acting as a primary barrier and meeting the waves at their most powerful. Existing maintenance routes for the tetrapods could also be used for the turbines, which the team predicts should have a lifespan of around 10 years. The next phase of the research will see two half-scale WEC turbines installed on a stretch of coastline, powering LED lights, but Shintake hopes the system will one day widespread adoption.
“I’m imagining the planet two hundred years later,” he said. “I hope these [turbines] will be working hard quietly, and nicely, on each beach on which they have been installed.”
Perhaps prof Shintake can do better than king Canute (Cnut nowadays); who demonstrated that man cannot control the seas. Looks a nice little turbine tho’: but what a life it would have!
Nodding ducks use wave energy to generate power while reducing erosion by reducing wave action.
I live quite near Canute’s-ford (Knutsford to those of us who know Cheshire which is about as far from the sea as one can get!) and have often wondered what he, with his wish to hold back progress -and the tide of advance analogy, simile, metaphor?) was doing so far inland?
Joking apart: presumably to the designers of a 21 century projectile loom, the earliest ‘wooden shuttle’ looms would look like museum pieces! -yet they were the for-runner of all that has developed. I like the concept of a two-for-one solution.
Multiple small robust turbines like this could be used for remote village power supply in rocky rivers in developing countries e.g. Peru, Sarawak, where large hydrokinetic turbines are not practicable. But they must be low cost.