An innovative use of marine energies can economically produce fifteen per cent of electricity

After having outlined some interesting characteristics and opportunities of marine energies, the author analyses the peculiarities of tidal energy, presents the different components of tidal power stations: tanks or basins, plants (horizontal bulb-turbines, orthogonal turbines). Then, he focuses on an innovative solution: tidal gardens which can be created as closed basins along the coast comprising channels equipped with tidal turbines, and sea walls. Performance of such an installation is assessed. Issues of production gain by pumping, of connection to the grid and energy storage are addressed. The construction modality is described. Visual impacts, impact on the environment, direct and indirect social-economic impacts are discussed. The issue of ship navigation is also addressed. The example of the Somme Bay is presented and assessed in terms of production, of costs (turbines, channels, main sea wall), of impacts, and of possible additional wind turbines. Other potential and more or less important sites in France, in Great-Britain, in India, Bangladesh and Korea, in America (Canada, Argentina, Brazil) and notably in Australia are identified and briefly assessed