Tidal Power

Tides represent a large and benign source of renewable energy which can be converted to electricity using well-proven technology. Further to this, the constant rise and fall of the tides mean they are also a predictable source of energy (Baker, 1999).

Tidal energy has been exploited since the 12th Century however developments in the field have evolved and conventional and new technology for generating energy can be used. Sine the construction of the La Rance tidal barrage in France in 1967, tidal energy has been increasingly exploited (O' Rouke et al., 2010).Typically a barrage with turbines, but sometimes a barrage on its own (that look similar to a wind turbine) is built across an estuary or a bay and as the tide ebbs and rises water can flow through the turbines and drive generators (Jacobson and Delucci, 2011).

One benefit of Tidal Power is that it is an extremely predictable energy source, depending only on the gravitational pull of the moon and the sun and the centrifugal forces created by the rotation of the earth–moon system (O' Rouke et al., 2010) and despite opposition from environmental groups the potential energy of the tide has proven to be successful (see graph below).

Major World Tidal Barrage Sites

In the UK tidal power is not used extensively. A key reason behind this is due to the inability of tidal power to be economically competitive with other traditional forms of energy. This disparity occurs as all the potential locations for tidal power in the UK have a mean tidal range of 5 metres which does not generate the energy desired (Baker, 1999). In addition to this, tidal power schemes run the risk of effected the environment due to the changes in salinity and salient regimes that they cause. Such changes could be hazardous as these components govern the primary conductivity of the water.

Current tidal current technology is currently not economically viable on a large scale as many technologies are in their early stages of development. Nevertheless, if developed these technologies offer a good way of generating renewable energy and if the environmental impacts were addressed then a positive path is paved for the future.