Ocean contains energy in the form of waves and tidal currents. Both can be used to produce electricity. Differential heating of the earth results in pressure variations in the atmosphere, which causes winds to be generated. Winds transfer some of their energy to the water when they pass over the surface of open bodies of water, resulting in the production of waves. The quantity of energy transferred and the magnitude of the ensuing wave are determined by the following factors: a) wind speed, b) wind speed over time, and c) wind distance. Wave energy conversion devices must generate a system of responding forces in which two or more bodies move relative to each other while at least one body interacts with the waves in order to extract this energy. A system like this can be designed to work with a variety of waves. Energy is extracted directly from surface waves or pressure variations below the surface via wave power devices. Generators store the energy taken from the waves. Offshore and onshore systems can both turn wave energy into electricity.