Harnessing the energy from these open-ocean currents requires the use of turbine-driven generators anchored in place in the current stream. Large turbine blades would be driven by the moving water, just as windmill blades are moved by the wind; these blades could be used to turn the generators and to harness the energy of the water flow.
Another proposal calls for a barge moored in the current stream with a large cable loop to which parachutes are fastened. The cable would be moved along by the current acting against the open parachutes. When the parachutes reached the end of the loop they would turn the corner and be dragged back against the current while closed. The continuous movement of the cable would be used to turn a generator to produce electricity.
Another exciting technology is the rim-driven turbine as exemplified by lorida Hydro Power and Light Company. The opportunities for further discovery and derived benefit from Newtonian and non-Newtonian process fluid mechanics, applied vortex hydrodynamics, and linear implosion technologies has just begun.