These wind turbines uses waves to harvest energy and to protect the coastline from erosion. Star-shaped concrete structures called tetrapods are often used to protect coastlines from eroding away under the constant barrage of waves. Now a project from the Okinawa Institute of Science and Technology (OIST) has outlined plans for turbines that would sit alongside tetrapods, helping to not only dissipate wave energy, but harvest it. Turbines would be placed in the direct line of fire, such as in front of tetrapods or around natural structures like coral reefs, to take advantage of fast-moving jet flows of water created where waves break. These Wave Energy Converter (WEC) turbines would be anchored to the sea floor with mooring cables, and peek up just above sea level where the waves can wash over them. Each turbine would feature five blades with a diameter of 70 cm (27.6 in) attached to a permanent magnet electric generator encased in ceramic to keep the damaging seawater out. The electrical energy created would be channeled through a cable in the support stem and back to shore to feed into the grid. [Source]