Wave/Tidal energy is something which has a huge amount of energy stored in it but its not been harnessed on a large scale till now. Now a company by the name Aquamarine Power has developed a power plant by the name Oyster. Its a pretty simple idea so to say but its very effective.
The device is a pretty simple hydraulic pump which is connected to a wide hinged flap.The hinged flap moves along with the waves in the sea, thus creating a movement in the hydraulic piston; this pumps the water through underground pipes to electric turbine where it is converted into useful electricity.The oyster is attached at the sea bed and pops 10mts above water.