Hydrokinetic power electric generation

Hydrokinetic power is electricity derived by converting the kinetic energy of moving water into electricity. Hydrokinetic power uses the natural flows in ocean currents and tides or inland waterways to create electricity. It is different from hydropower in that hydropower requires the impoundment or diversion of water and hydrokinetic power does not.

Technologies used to generate hydrokinetic power are varied, with most in the research and development phase where many different options are being tested. Hydrokinetic technologies are classified as either wave energy converter (WEC) or current energy converter (CEC) devices depending on the type of water movement that is converted to electricity.

WECs use the motion of two or more devices relative to each other. One of these devices, called the displacer, is acted on by the waves. The second device, the reactor, moves in response to the displacer and drives a generator to create electricity. 

CECs, also called rotating devices, are spun by the kinetic energy of moving water as tidal streams, ocean currents, or river currents strike a rotor. The spinning rotor drives a generator to create electricity.

There are two principal types of CEC devices used for hydrokinetic power. These are axial flow turbines and cross flow turbines.

Hydrokinetic devices generate power at the device. The power is then transmitted via underwater cable to an onshore step-up transformer and then into the transmission grid. Since hydrokinetic power is usually located remotely from load centers, projects will be centralized and connected to the transmission grid.