Relying solely on the orbits of the moon, Earth and Sun, tidal energy is reliable, inexhaustible and largely predictable. EU-funded researchers successfully developed a new type of tidal energy generator prototype that is significantly cheaper and more efficient, also replacing conventional magnetic materials.
Design of tidal energy generators is often adapted from those used for wind energy, but the needs of undersea generators are quite different. Tidal stream generators need to be able to remain efficient at low rotational speeds and cope with large and highly variable torque levels. All these can put generator gearboxes under significant strain and lead to poor reliability.
Further details: New materials to capture tidal energy