The ocean's waves harbour tremendous amounts of raw energy and represent the single largest untapped source of renewable energy today. Converted into electricity, wave energy could potentially satisfy up to one tenth of current global power demands.
Waves are created when wind moves over the ocean surface. Even small ripples on the surface offer the wind a steep slope against which to push, causing the waves to grow and travel forward. In deep waters, waves can travel thousands of nautical miles until their energy dissipates on distant shores. Wave energy produced anywhere in an ocean basin ultimately arrives at its continental shelf margin virtually undiminished until it reaches the depths of about 200m. The interaction between the waves and the sea bottom gradually reduces the high levels of power in the waves. (For more see Near-shore vs. Off-shore wave energy resources).
The combination of the Earth's rotation and the westerly direction of prevailing winds means that high wave energy resource regions are typically located along the western coasts of the continents. This is especially true of locations where waves can travel without any obstacles for thousands of nautical miles.
Moreover ocean waves are consistent and sea states can be accurately predicted more than 48 hours in advance. Accurate wind forecasts, in contrast, are only available for 5-7 hours beforehand. Other factors that make wave energy especially attractive for electricity generation is its high power density compared to the power density of solar or wind energy.