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Why wave energy? - Due to the high energy density

Ocean waves are created by wind blowing along at sea-level. Furthermore, the wind is created by the sun as its heating creates low and high atmospheric pressure. Only a portion of the solar energy is converted into wind energy, and of this only a portion is transformed into wave energy. But in both these energy transformations, there is an increase of the energy density. Just below the sea surface, the average energy density is many times higher than the density of wind energy. When the wind blows in the same direction over time, a dominant wave direction is created which coincides with the wind direction. The high energy density means that a properly designed wave energy converter, will have a beneficial relationship between the size of the structures and the energy produced. In this fact, there is a promise that wave energy will have competitive energy prices in the long term.

The No-conflicts resource

Floating wave energy is a low-conflicts resource. Wave energy converters wil be installed in large energy parks far out to sea beyond sight from the coast and conflicts to coastal landscape, and connected to the power-grid with a single floating- or underwater station and a single sub-sea power cable to shore. Furthermore, the system will not compete with fishing, marine life or traffic at sea since the floating systems give a wide choice of localizations, also with regard to water depth.

In this context, one should also look at the development of wave energy in relation to business development and jobs in the maritime sector. An industrialization of wave energy provide a more real and sustainable economic addition to this sector, than any other energy explorations.

Global Resource

The World Energy Council has conservatively estimated that the realistic electricity production from wave energy, could be in excess of 2,000TWh/year. Wave energy also has the benefit that it follows the seasons variation, in that there is more wave energy in winter when more energy is needed. The map under shoves the average global wave energy potential.

Wave Energy Levels in kW/m Crest Length

What happens in an ocean waves? Energy, not water or ocean, is transported along at sea-level. Water particles move only in small circles as the wave passes, as shown in the figure. In deep water, the particles move in circles (A), whereas in shallower water, the movement is more and more elliptical (B). particle movement also takes place under the water surface, but is quickly reduced as one goes deeper in the water.

For more reading about wave energy:

open wave energy project

Ocean Energy Systems Implementing Agreement (OES) by IEA

Professor Johannes Falnes' web pages with list of wave power books