Until the last decade large-scale tidal range systems dominated the tidal power scene. Concerns over the health of shoreline and aquatic ecosystems mar this otherwise clean source of energy. Though tidal energy is carbon free, tidal range technologies have not proven to be environmentally benign.

Tidal energy is considered renewable because the tides move on a predictable, daily schedule, depending only on the orbits of the Earth, Moon, and Sun, and are essentially inexhaustible. Tidal stream turbines come in many shapes and sizes but the most common designs are basically underwater wind turbines. They harness fast-flowing currents to spin turbines. The second technology is newer and just beginning to be tested out on a commercial scale around the world, so-called tidal stream technologies. The first and best known are tidal range technologies which harness power through dam-like structures that trap rising waters on one side and then release it back to the other through turbines that spin to generate electricity. There are two main branches of technology that tap the tides for energy.

Tidal power exploits energy drawn from the movement of ocean tides to produce electricity.

Generating capacity of the proposed Severn tidal lagoons in the UK, costing $65 billionĬost of electricity from the first tidal stream farms, comparable to the cost of wind power in 1980Ĭountries currently investing in tidal power research Total potential capacity of the 27 best locations in the world for tidal stream farmsĬost of power generated by the La Rance in France tidal barrage, cheaper than most competitors Tidal range of Nova Scotia's Bay of Fundy, the largest in the world

Tidal turbine