Power derived from forces produced by ocean waves. Waves are caused by the wind blowing over the surface of the ocean. In many parts of the world, the wind blows with enough consistency and force to provide continuous waves. Wave power devices can extract energy from the surface motion of these waves as well as from pressure fluctuations below their surface. Wave energy technology is still undergoing further development, but estimates see potential world-wide electricity contribution to reach between 10 to 15 percent of yearly demand. Wave energy could play a major part in efforts to combat climate change, displacing 1 – 2 billion tons of carbon emissions per year from conventional fossil fuel sources.