Tidal Power
There are basically two methodologies for creating tidal power: the use of tidal dams or ocean currents. Dams are based on using a barrage at a bay or estuary with a large tidal range. Power is generated primarily at ebb tides as the barrage creates a significant head of water, much like a hydroelectric dam. This technology is very well established at La Rance, France where a 240MW plant has operated since 1966. A 20MW facility has also been present in Annapolis, Nova Scotia since 1984. However, estuaries are amongst the world’s most productive and sensitive ecosystems, and the flooding by these barrages causes a great disruption to their natural processes. In the context of ocean energy, barrage based tidal power is not considered a truly sustainable resource.
The sources of Blue Energy’s tidal power production are fast flowing tidal currents. The gravitational pull of the moon causes water to flow in from the ocean twice a day on the flood tides, and outward during ebb tides. Additional monthly and annual lunar cycles vary the strength of these currents. Narrow and shallow constrictions produce the fastest and most powerful movements of current, whose energy can be harnessed using the Blue Energy Ocean Turbine. This energy source is independent of weather and climate change and follows the predictable relationship of the lunar orbit that is known many years in advance.
