Energy is required in almost all aspect of everyday life including agricultural, drinking water, lighting health care, telecommunication, and industrial activities. Use of fossil fuel also made a side effect. Their combustion product will make pollution, such as global warming, acid rain and so on. Conversion to clean and environment friendly energy sources such as solar energy would enable the world to improve the quality of life throughout the planet Earth, not only for humans, but also for its flora and fauna as well. Renewable energy sources, such as biomass, solar, ocean thermal, wind, currents, tides, waves, geothermal etc., are being considered as possible sources of energy to meet these challenges.
The ocean can produce two types of energy: thermal energy from the sun's heat, and mechanical energy from the tides and waves. Oceans cover more than 70% of Earth's surface, making them the world's largest solar collectors. The sun's heat warms the surface water a lot more than the deep ocean water, and this temperature difference creates thermal energy. Just a small portion of the heat trapped in the ocean could power the world. Ocean thermal energy is used for many applications, including electricity generation.
Ocean mechanical energy is quite different from ocean thermal energy. Even though the sun affects all ocean activity, tides are driven primarily by the gravitational pull of the moon, and waves are driven primarily by the winds. As a result, tides and waves are intermittent sources of energy, while ocean thermal energy is fairly constant. Also, unlike thermal energy, the electricity conversion of both tidal and wave energy usually involves mechanical devices.
