Dòng đại dương đại diện cho một đáng kể, hiện nay chưa được khai thác, hồ chứa năng lượng. Tổng số năng lượng trên toàn thế giới trong dòng chảy đã được ước tính là khoảng GW, với mật độ điện lên đến 15 kW/m2. | Next generation green technologies 119 Ocean currents represent a significant currently untapped reservoir of energy. The total worldwide power in ocean currents has been estimated to be about 5 000 GW with power densities of up to 15 kW m2. In large areas with powerful currents it would be possible to install water turbines in groups or clusters to create a marine current facility. Turbine spacing would be determined based on wake interactions and maintenance needs. A 30 MW demonstration array of vertical turbines in a tidal fence is being investigated in the Philippines WEC 2001 . However a number of potential problems need to be addressed including avoidance of drag from cavitations air bubble formation that creates turbulence and decreases the efficiency of current-energy harvest prevention of marine growth build up corrosion control and overall system reliability. Because the logistics of maintenance are likely to be complex and the costs potentially high system reliability is of high importance. Ocean currents flow relatively steadily throughout the year and in some cases the flow is considerable. An example is the Straits of Florida where the Gulf Stream flows out of the Caribbean Sea and into the North Atlantic on its way to northern Europe. The speed of the current is around km h at the surface but it decreases with depth. There is a potential extractable power of 1 kW m2 near the surface. A 300 kW full-scale plant installed by Marine Current Turbines MCT has been operating at Lynmouth Devon UK since May 2003. MCT has also been planning deep sea marine current systems which could be constructed in large farms and thus use economies of scale both in construction and maintenance and in the infrastructure for bringing the electricity to shore. Another approach which has identified the potential of the Gulf Stream is the Gorlov helical turbine a vertical-axis turbine which is being currently prototyped in South Korea. No currently operating commercial .
