Wave energy conversion

The world's oceans are home to many sources of renewable energy, virtually untapped today. These include :

• tidal energy, well known in France with the example of the Rance tidal power plant;

• current energy with tidal turbines;

• deep offshore wind energy, where innovative floating foundations need to be designed;

• Thermal energy from the seas, in tropical areas, where the difference in temperature between warm surface waters and the cold waters at great depths (1,000 to 2,000 m) is exploited;

• energy from salinity gradients, at river mouths where the difference in salinity between freshwater and seawater is exploited by osmotic pressure;

• and finally, wave energy, the waves that animate the surface of the oceans. It's the recovery of this last form of marine energy that is the subject of this article.

On a global scale, the technically exploitable potential of wave energy is estimated at around 30,000 TWh/year (1 TWh = 1 billion kWh). If we compare this figure with global energy consumption in 2008, which was in the region of 100,000 TWh, we realize that wave energy is not the only definitive solution to the energy crisis, but that it can make a significant contribution.