State of the art in tidal current energy extracting technologies

The potential of electric power generation from tidal currents is enormous. Tidal currents are being recognized as a resource to be exploited for the sustainable generation of electrical power. The high ocean water density leads to that tidal current turbine blades size are much smaller than wind turbine blades for the same power level. Additionally, tidal source is highly predictable for long time. Those characteristics make tidal current extremely promising and advantageous for power generation when compared to other renewable energy resources. The technology used for harnessing tidal current energy mainly based on the relevant work which has been carried out on ships propellers, wind turbines and on hydro turbines. This paper reports tidal power fundamental concepts and two currently used source modeling methods. The most promising tidal turbine projects worldwide are classified depending on the structure of turbine and some brief notes are given. Furthermore, it will also discuss the possible generator choices and system topologies.