Tidal Power

This page is set to redirect to http://energysourcefacts.org//. If it does not redirect, please click here





Tidal power is a form of hydro power utilizing the energy of tides for the generation of eco-friendly electricity. In spite of the fact that it is not yet widely used, tidal power definitely has potential for future electricity generation. Compared with solar power as well as wind energy, an advantage of tidal power can be seen in the circumstance that tides are more predictable than wind or the sun. Tides have their origin in the tidal forces generated by the moon and the sun on the one hand as much as the rotation of the earth on the other hand. For this reason tidal power which is classified as a renewable energy source, is practically inexhaustible. For the generation of electricity the strength of tides is of great importance. The stronger the tides, either in water level height or tidal current velocities, the greater the potential for tidal power generation which from the technical point of view is realized by the use of large underwater turbines. These are placed in areas with high tidal movements. The design of the underwater turbines allows to capture the kinetic motion of the ebbing and surging of ocean tides in order to generate electricity. By tradition, tidal power is also obtained by building semi-permeable barrages across estuaries with a high tidal range. Barrages allow tidal waters to fill estuaries via sluices as well as to empty through turbines. Since barrages can have a negative effect on animals and plants in estuaries, tidal fences more often are used instead. Apart from the fact that they have less impact on the environment than barrages, they are also cheaper to install. Compared with barrages and tidal fences, underwater turbines are a fairly new technology which can be located anywhere there is a strong tidal flow. Since water is about 800 times denser than air, underwater turbines need to be much sturdier than wind turbines. Therefore, they are also heavier and more expensive but able to capture more energy, too. Since 70 % of the earthÇs surface are covered with water, a great amount of power could be generated by placing turbines at locations with high tidal movements. Estimations assume that at least 30 % of the required energy world wide could be covered by tidal power.

Except for harnessing energy from the tides, there is another technology of generating power from the ocean. Energy can be generated by the means of wave power. One of the methods that allows to generate power from waves works like a swimming pool wave machine in reverse. At a wave power station the arriving waves cause the water in the chamber to rise and fall. This means that air is forced in as well as out of the hole in the top of the chamber. A turbine is placed in the hole which is turned by the air rushing in and out. An advantage of wave power is the fact that it is inexpensive as far as its operation and maintenance is concerned. Apart from that it can generate a great deal of energy. A disadvantage of wave power is the dependence on the strength of waves. Furthermore wave power stations must be able to withstand very rough weather conditions and some designs can also be very noisy.