The first tidal dam was constructed in 1960 in La Rance, France. Since that time only a hand full of tidal dams have been constructed throughout the world. Even with a rising demand for energy tidal power has not been able to find a suitable balance between the advantages and disadvantages of a project. Some of the disadvantages to tidal power are:
- Variations in tidal range cause the output to not uniformed throughout the day.
- Because of the variation of headwater throughout the day, the plants effectiveness is slightly compromised.
- Maintenance of machinery is difficult when preformed underwater or at sea.
- Construction of a solid tidal dam is difficult with tide changes.
- The corrosives nature of seawater is proven to corrode untreated modern machinery.
- Tidal fences in order to mitigate fish migration would be difficult to construct and maintain.
- Generation posts are usually far away from collection stations, leading to high cost of transmission lines.
- Tidal is a time-specific base load, meaning it cannot conform to peak demands.
All of these disadvantages lead to tidal power currently not proportionately cost effective to the amount of energy that is produced. However, with advantages such as no pollution produced, little cost for usable land, and completely independent of the cycle of rain, tidal power will continued to be researched for the future. Technological advancements in turbine technology may eventually see large amounts of power generated from the ocean and tidal currents using the tidal stream designs.
To view a simple demonstration of how tidal power works, click the link bellow.