The massive oceanic surface currents that exist on Earth today are one of many unused reservoirs of energy that we could tap into. Their total output of energy has been estimated at approximately 280-trillion watt – hours. Ocean surface currents are considered an indirect form of solar energy because of their link to surface heating processes as well as the winds.

Scientists have developed a device that can harness energy from slow-moving rivers and ocean currents, which have the ability to power the entire planet. All that is required for the technology to work is a simple water way or sea bed. The technology can generate electricity in water flowing at a rate of less than one knot. The device is made up of cylinders that are positioned horizontal to the water flow. The cylinders create vorticies as the water flows past, which allow the cylinders to be pushed and pulled up and down. The energy this action creates can be converted to electricity. Cylinders arranged over a cubic metre of the sea or river bed in a flow of three knots can produce 51 watts. This is more efficient than similar-sized turbines or wave generators and the amount of power produced can increase extensively if the flow is faster or if more cylinders are added.

f we could harness 0.1 per cent of the energy in the ocean, we could support the energy needs of 15 billion people. In the English Channel, for example, there is a very strong current, so you produce a lot of power” – Michael Bernitsas, Professor of Naval Architecture at the University of Michigan

The system is called a vortex induced vibrations for aquatic clean energy (VIVACE). It is modeled after the way fish swim through water, how they glide between the vorticies created by the bodies of other fish swimming ahead of them, they ride each others wake.

http://www.collective-evolution.com/2013/01/11/vortex-induced-vibrations-ocean-currents-could-power-the-entire-planet/