Wave Energy Resource
Wave particles move more or less in an orbit but in open water usually not in a regular way as many wave patters interact with each other. If energy is extracted from only the up and down movement, the need arises to develop mechanisms that make a WEC resonate with the waves. When energy is harnessed from all directions, a device can move along the orbital wave path. In larger waves, it simply makes larger circles, always following the present wave, high or low, short or long, steep or shallow. Advantages of such a system would include: power generation from heave (vertical), surge (horizontal) and sway (lateral) motions, no acceleration and deceleration losses and no energy loss from making the device resonate with the waves.
Wave Particles
In the North Sea most wave energy is usually found till 4 or 5 meter under the surface. In oceans, where waves are longer, considerable energy can still be found at 10-12 m.
Wave Density
Wave energy is proportional to the square of the wave height; double wave height = 4x more energy. In our part of the North Sea, the usual wave height for which a device gets designed would lie around 3-4m in area's where the mean yearly wave energy density would lie between 10 and 20 kW/m wave front. In oceans that could be up to 7m wave heights and 60-70 kW/m wave front.
Wave energy is generally considered to be the most concentrated and least variable form of renewable energy. It is the high power density of wave energy that suggests it has the capacity to become the lowest cost renewable energy source. The World Energy Council has estimated that approximately 2 terawatts (2 million megawatts), about double current world electricity production, could be produced from the ocean waves.
– Center for Wave Energy