Operation and Control of Renewable Energy Systems

Chapter 10Ocean Energy

10.1 Energy from Ocean

Oceans, covering over 70% of the Earth's surface, are the world's largest collector and retainer of the Sun's vast energy. This vast energy from the oceans is available in the form of tides, ocean thermal (due to temperature difference), ocean currents and waves [1–3]. Tidal energy is the oldest form of renewable energy, which was used in the water mills by the Romans when they occupied England. Tidal mills were also built in Spain, France, United Kingdom and China during medieval period, around AD 1100. However, it was not until the 20th century that it was investigated as a potential source of electricity. The first ever tidal power plant was opened in 1966 in La Rance, France. It has reliably generated power for more than 15 h/day and has delivered 500–600 GWh annually since 1967. However, this type of plant was not erected in other areas owing to the high cost of power plant components and difficulty in locating sites in which such power plants could be built. Now in order to find new renewable energy sources, there is renewed interest in these technologies. Significant growth has occurred in the number of devices developed for ocean energy conversion since 2003. Many countries are now involved in finding new technology and in research and development for application of ocean energy.

Tidal energy is clean renewable green energy and is non-polluting, reliable and predictable. In 1687, Sir Isaac Newton explained that ocean tides ...