One of the possible alternatives is to capitalise on the energy that can be captured through the flow of water, known as hydrokinetic energy. Unlike hydropower, which refers to the energy produced in hydroelectric dams, hydrokinetic power is created by harnessing energy from the natural velocity of water. Ocean surface currents are caused by wind energy that is transferred into the water. They are affected by the direction and speed of the wind, tides, the temperature and the salt concentration of the water, the rotation of the earth, gravity, and even the landscape of the bottom of the ocean. However, ocean currents follow relatively constant patterns. North of the equator, currents generally flow clockwise, while south of the equator, currents generally flow counter clockwise. Although its speed may vary, the Gulf Stream, located near the East Coast of the United States, travels at a velocity between 3 or 4 knots, which is approximately 4 miles per hour. This velocity is more than enough to power turbines similar to those used in a coal power plant and generate electricity by using a clean, renewable source of energy.
Generating power from ocean currents is a relatively new idea that is still at an early stage of development. Many different prototypes exist, but no commercial turbines are currently in operation. Harnessing ocean current energy does not pollute the water or the air, and turbines do not release any greenhouse gases into the atmosphere. One of the only dangers that exist is to the fish swimming close to the blades of the turbine, but engineering has provided solutions that render these generators completely harmless. In theory, hundreds of thousands of turbines could also cause the currents of the world to slow down, which would lead to dramatic changes in temperature. However, with careful planning, this can be avoided.

Different Ocean Current Turbine designs

The World's Major Ocean Surface Currents