Globally, significant ocean current streams are largely concentrated on the eastern coasts of continents because of the earth’s rotation, and, especially in the more northerly and southerly latitudes, because of lunar gravitational pull.
In addition, there are locations where the topography creates significant flows, such as the Chacao Channel in southern Chile. It has been said that more water flows past Fort Lauderdale, Florida than is contained in all the rivers of the world combined. Unfortunately, most devices at present rely on massive bases to withstand the force of the current; this restricts the depths in which they can operate, since the swiftest currents are near the surface such as the Gulf Stream off the coast of Florida.
A major problem in trying to exploit these flows is transmitting the energy to market. For example, the southern end of Argentina and the east coast of Sakhalin Island, Russia, each have potentially productive ocean current energy generation sites, but lack nearby markets for electricity. By contrast, in South Africa, where the Agulhas Current is located, the local utility is seeking to develop the country’s extensive solar resources in the Kalahari Desert, far from its industry, which is located mostly on the water and therefore much nearer to the aforementioned current. Naturally, ocean current energy generation could be economically feasible in this case, because of the advantage it has in proximity to the consuming market. Other similar prime locations include Florida, Japan, Korea and China.