 Marine energy, also known as "ocean energy" and "marine and hydrokinetic energy" (MHK) includes tidal and wave power and is a relatively new sector of renewable energy, with most projects still in the pilot phase, but the theoretical potential is equivalent to 4–18 Mtoe.MHK development in U.S. and international waters includes projects using devices such as, wave energy converters in open coastal areas with significant waves, tidal turbines placed in coastal and estuarine areas, in-stream turbines in fast-moving rivers, ocean current turbines in areas of strong marine currents, and ocean thermal energy converters in deep tropical waters.Wind power is growing at the rate of 17% annually, with a worldwide installed capacity of 432,883 megawatts (MW) at the end of 2015, and is widely used in Europe, Asia, and the United States.