The worldwide potential for tidal power is estimated to be 700 TWh a year. Currently, tidal power is early in the development stages and not able to compete with fossil fuels. However, Focus on renewable energy sources and demand for clean energy contributes to a rapid development of methods to harness this energy source. What are the pros and cons of tidal energy and what can we expect in the future?     Advantages of Tidal Energy Renewable Tidal Energy is a renewable energy source. This energy source is a result of the gravitational fields from both the sun and the moon, combined with the earth’s rotation around its axis, resulting in high and low tides. It is this difference in potential energy that is the source of power generation from tidal energy, whether we are talking about stream generators, tidal barrages or more the more recent technology, dynamic tidal power (DTP). So, why is tidal energy renewable? Compared to fossil fuels or nuclear reserves, the gravitational fields from the sun and the moon, as well as the earth’s rotation around its axis won’t cease to exist any time soon. Green Tidal power is an environmentally friendly energy source. In addition to being a renewable energy, it does not emit any climate gases and does not take up a lot of space. However, there are currently very few examples from real tidal power plants and their effects on the enviroment. An important task is therefore to study and assess these things. Predictable Tidal currents are highly predictable. High and low tide develop with well-known cycles, making it easier to construct the system with right dimensions, since we already know what kind of powers the equipment will be exposed to. Because of this, even though the turbines that are being used (tidal stream generators that is) are very similar to wind turbines, both the physical size and the installed capacity has entirely other limitations. Effective at Low Speeds Water has 1000 times higher density than air, which makes it possible to generate electricity at low speeds. Calculations show that power can be generated even at 1m/s (equivalent to a little over 3ft/s). Long Lifespans We have no reason to believe that tidal power plants are not long lived. This ultimately reduces the cost these power plants can sell their electricity, making tidal energy more cost-competitive. The tidal barrage power plant La Rance was opened already in 1966 and still generates large amounts of electricity. Disadvantages of Tidal Energy Environmental Effects As previously mentioned, the effects tidal power plants have on the environment are not completely determined yet. We know that these power plants generate green electricity Tidal barrages relies on manipulation on ocean levels and therefore potentially have the environmental effects on the environment similar to those of hydroelectric dams. Technological solutions that will resolve some of these issues are currently being developed. Close to Land Tidal power plants needs to be constructed close to land. This is also an area where technological solutions are being worked on. Hopefully in a few years we can exploit weaker tidal currents, at locations further out in the sea. Expensive It is important to realize that the methods for generating electricity from tidal energy is a relatively are relatively new technologies. It is projected that tidal power will be commercially profitable within 2020 with better technology and larger scales. Other articles on tidal energy can be found in the Tidal category. You might also want to read Hydroelectric Energy pros and Cons.

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For centuries, mankind has exploited this massive energy source. In the recent years, we have learnt how to generate electricity from it. 450 TWh is the estimated yearly potential of electric power that can be produced from tidal energy. In addition to this comes a large and not yet estimated potential in river flows.       What is Tidal Energy? Tidal energy or tidal power can be defined as the energy that is the result of the moon and the sun’s gravitaional influence on the ocean. Height differences between high and low tides create tidal currents in coastal areas, and these currents can be strong enough to drive turbines.     Where is Tidal Energy Used? As tidal power generation is relatively new, there are not a lot of tidal energy companies out there developing investing in this technology yet. However, there are several tidal power plants in use and more is coming. Some of these are solely for research and experimental purposes, but the number of commercial tidal energy power plants is increasing. La Rance tidal power station was the first large large-scale tide energy project and was opened already in 1966. It lays in the water-rich river Rance in the north-western France. This is a tidal power plant with a total installed capacity of 240 MW capacity generated from 24 turbines. Annual production of electricity is about. 0.6 TWh (600 GWh), which means that the average effect of day throughout the year is 68 MW. La Rance is a form of what we call a tidal barrage power plant.   Tidal Barrage Energy A tidal barrage power plant consists of three main parts: The first being the barrage itself, holding the water back during high tide. The second part is the sluice gate that let water through the third part, the turbine and generator, resulting in electricity generation. The sluice gates are left open during high tide and closed during low tide to create a water level differential, creating a potential difference that powers the turbine when the water is released.   Tidal Stream Generator Tidal stream generators are very similar to wind turbines except their below the water surface instead of above or on land. The turbine and generator converts the movement of water coming from change in tide, the kinetic energy, into electricity. Water is 830 times denser than air and therefore can generate electricity at lower speeds than wind turbines.   Dynamic Tidal Power Dynamic tidal power is still in the development stage. The theory of this technology is that we can exploit tidal flows and their interaction between potential and kinetic energy.   Advantages of Tidal Energy There are several advantages with tidal power generation. The greatest benefit after the fact that tidal energy is both a renewable and a green energy source is the incredible potential it posses. The large density of water, almost 1 000 times greater than in air, results in very large amounts of energy to get out of the tidal currents even if the speed is low. Tidal currents are very predictable, and therefore very favorable with respect to the planning of production and maintenance. For a full overview over the advantages of tidal energy as well as the disadvantages go to Tidal Energy Pros and Cons. I hope you learned by reading this article how tidal energy works and realize what big potential these methods of harnessing energy really have. More tidal energy and tidal power facts can be located in the Tidal category.

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