OKINAWA, JAPAN — Japanese researchers have come with special technology that can not only capture energy from waves, but also help protect coastlines.

According to the Okinawa Institute of Science and Technology, a team led by Professor Tsumoru Shintake plans to set up energy-harvesting turbines near tetrapods, which are concrete structures placed along the shore to weaken the force of incoming waves and prevent erosion.

The turbine has five flexible blades modelled after dolphin fins. It's supported by a stem that's anchored to the sea floor with mooring cables, which, like the blades, is flexible and can bend under pressure.

Inside the turbine head is a magnet electric generator, which transforms wave energy into electricity. The electricity is sent back to the shore via cables, to feed into the grid.

Using turbines on just 1% of Japan's coastline can generate roughly 10 gigawatts of energy, equivalent to about 10 nuclear power plants.

Apart from tetrapods, the turbines can also harness electricity near coral reefs.

They're built to be safe for marine life, with blade speed carefully calibrated so that any animals caught in them can escape unharmed.

The team is currently preparing to install two half-scale model turbines that will power LEDs as part of a commercial demonstration.