Waves have a lot of energy
Source: Marine and Hydrokinetic Technologies Program, U.S. Department of Energy, Energy Efficiency and Renewable Energy (public domain)
Source: Adapted from National Energy Education Development Project (NEED)
Source: Tuscanit, Wikimedia Commons author (GNU free documentation license) (public domain)
Waves form as wind blows over the surface of open water in oceans and lakes. Ocean waves contain tremendous energy. The theoretical annual energy potential of waves off the coasts of the United States is estimated to be as much as 2.64 trillion kilowatthours, or the equivalent of about 65% of U.S. electricity generation in 2015. The west coasts of the United States and Europe, and the coasts of Japan and New Zealand, have potential sites for harnessing wave energy.
Different ways to channel the power of waves
One way to harness wave energy is to bend or focus waves into a narrow channel to increase their size and power and to spin the turbines that generate electricity. Waves can also be channeled into a catch basin or reservoir where the water flows to a turbine at a lower elevation, similar to the way a hydropower dam operates.
Many other methods of capturing wave energy are under development. These methods include placing devices on or just below the surface of the water and anchoring devices to the ocean floor. The U.S. Department of Energy's Marine and Hydrokinetic Technology Database provides information on marine and hydrokinetic renewable energy, both in the U.S. and around the world.