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Potential environmental issues

Although the basic process of tidal power harvesting is the same for centuries, and the average efficiency of the mechanical tide energy conversion on electricity is not surpassing yet 50% signify- types of devices for the waves and currents harvesting from seas and oceans (fig.2), but the existing demonstrators didn’t reached yet either the energy efficiency or the economical efficiency threshold for large scale use.

Potential environmental issues

Although the basic process of tidal power harvesting is the same for centuries, and the average efficiency of the mechanical tide energy conversion on electricity is not surpassing yet 50% significant progress is expected from the computer aided design of the new turbines shape and geometry, new advancements in material science and proper distribution of the tide current turbine grids (fig.7 a, b, c, d). However, the system has some disadvantages as long as the turbine generation, nourished from the flow of the tidal stream, will likely generate a swirl of water downstream of the turbine. This horizontal vortex may cause erosion, if it touches the bottom (fig.8).Neither offshore bottom area, nor its ecosystem will be preserved entirely on a long term use of the tidal system –presently being obvious that sometimes fishes are fatally fascinated by the turbine vortexes. Dams and turbines separates estuary from the rest of the body of water and changes salinity of habitat. Researchers found that only after

10 years, species showed signs of adaptation to new conditions. Some types of turbine have sonar detectors; when dolphins come by they shut off.

Bibliography

Bahaj, A S and Myers, Fundamentals of marine current turbines, Renewable Energy 28, L E (2003)

Iconography

www.marineturbine.com

www.space.dtu.dk/English/Research/Scientific_data_and_models/Global_Ocean_Tide_Model.aspx

http://.interestingenergyfacts.blogspot.com/2008/03/ocean-energy-facts.html

http:\\hydrovolts.blogspot.com\2009_04_01_archive.html

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