6 - Other Possibilities of Marine Energy Conversion

Abstract

The differences in solar influx in various parts of the ocean induce water temperature and salinity changes that lead to the constitution of water bodies with different characteristics. Such dissimilarities associated or not with the other forces, which act on the oceanic masses, create marine currents. The expression marine currents covers a whole set of extremely complex water movements and exchanges between different oceanic regions. Marine currents can be permanent or seasonal, both in magnitude and direction, and are very difficult to observe and study because of their superimposition on the general oceanic circulation of many local transient phenomena. The energy in a marine current is utilized in the same manner as the wind energy. Although the medium for the utilization of marine currents is water, the turbines are more like wind turbines than water turbines. The reason for this is that no dams are built as for water turbines because no potential head is available and only a part of the kinetic energy in the current is extracted.