Tidal Power: A Renewable Energy Option for Coastal Areas

Hydroelectric power relies on the gravity moving river water through a narrow channel in the damn to turn its turbines, but there is another way electricity could be produced by water making use of the tides of the world's ocean. Tidal Power plants work in a manner similar to other hydroelectric power generators, although the dam required is much larger. Ships are allowed access through the dams through the series of locks. The drawback of the dam or barrage scheme is that there are only a limited number of sites where such tidal power plants can be built. The Severn Estruary in Great Britain is one area where engineers are looking to build a barrage tidal power plant.

The Barrage system is not the only means by which tidal power plants can produce electricity. Another system that uses turbines that get turned by water in a manner similar to the turbines used by wind farms has fewer problems. The number of sites where such tidal power plants can be constructed is far greater.

Two forms of the potential tidal power turbines exists offshore turbines and swan turbines. Offshore turbines are driven into the seabed, but the twin turbines currently in use at the world's offshore tidal power turbine stations have generators that can be raised above the sea level to allow for maintenance and repairs as needed. The Swan turbines are designed in a manner that not much can go wrong with them when they are used to generate tidal power. Instead of being anchored into the seabed, they are built using gravity bases to leave them at the bottom of the floor and are connected directly to the generator. In both swan turbines and the offshore turbines, underwater wires connect the generators to the areas that need the electricity provided.

The major downside of tidal power is that it can only be used in areas where there are strong tides, or in the case of the swan power systems, where there is enough current to drive the blades continuously. Tidal power may not be ideal everywhere, but it can help countries reduce their carbon emissions in areas where such plants can be operated effectively. The chief advantage is that tidal power will continue to operate as long as the Earth experiences tides.

Sources:

http://home.clara.net/darvill/altenerg/tidal.htm

http://news.bbc.co.uk/2/hi/science/nature/7013068.stm

http://www.marineturbines.com/technical.htm