8 Key Pros and Cons of Tidal Energy

8 Key Pros and Cons of Tidal Energy

by / Comments Off / 80 View / Jan 5, 2015

Renewable energy is the path forward. The sooner we switch to renewable energy sources, the better it is for the world and for us. Everyone knows that finite resources like fossil fuels or coal would dry up, sooner than later. Yet, the world has not progressed enough to develop renewable energy on a war footing. There are some hindrances in harnessing the power of sun, wind, water or tidal energy, but the process has to be sped up if the world’s energy requirements are to be met in the near future.

Tidal energy is one of the best renewable energy sources. Wind power is unpredictable, solar power takes a lot of space to be harnessed in great quantum and conventional hydropower projects have their own set of challenges. While every renewable energy source should be explored, tidal energy should be among the priorities. An estimated 700 TWh of power can be generated in a year by harnessing tidal energy.

Harnessing tidal energy involves tapping the natural low and high tides. The tides are caused due to the varying gravitational fields of the moon and the sun along with the rotation of earth around its axis. Tapping the energy generated by tides can certainly meet our energy needs, in a desirable way. However, there are some challenges or disadvantages of tidal energy that have to be looked into as well. Here are some tidal energy pros and cons that need to be highlighted.


1. The biggest advantage of tidal energy is that it is renewable. The sun, moon and earth are going to be around and the gravitational fields will be at play. Consequently, we would have high tides and low tides. There wouldn’t be a time, in the foreseeable or unforeseeable future, when we won’t have tides.

2. Tidal energy is environment friendly. One of the biggest advantages of most renewable energy sources is that they are all green or eco friendly. One doesn’t have to worry about mining or excavations, carbon emissions or biohazards. Tidal energy can be generated without contributing to carbon emissions, particulate matter and toxic gases in the environment. From another perspective, tidal energy would actually make the world a better place. The availability of tidal energy will reduce our dependence on coal and fossil fuels which will in turn reduce the carbon footprint and global warming could be tackled in a much more efficient and effective manner.

3. Tidal energy would be bankable. Tides are extremely predictable. For many centuries, we have predicted tides with absolute accuracy. The precise times can be predicted because tides seldom show any changes in their occurrence, frequency or intensity. Tides tend to follow a cycle and we know that cycle too well. Wind power is less dependable because of the unpredictability of wind itself. Such a problem doesn’t persist with tidal energy.

4. In comparison with wind power, tidal energy is much more powerful. Water is a thousand times denser than air. Harnessing wind power will require strong winds. Harnessing tidal energy does not require very high speeds. Low speeds or gentle tides can also be harnessed.

5. Tidal energy is cost effective as the plants have a long lifespan. The investments can be safely recuperated and there can be handsome returns thereon. As an example, there is a tidal barrage power plant at La Rance which has been operating since 1966 and it is fully operational today, functioning at optimum capacity and generating a lot of electricity.


1. One of the most concerning disadvantages or concerns is the environmental impact of harnessing tidal energy. Tidal energy is green and eco friendly and it doesn’t cause any immediate harm to the environment in ways that concern us now. But we don’t know for certain what kind of impact it would have on the environment at large. Harnessing the power of the tides is manipulating the tides, seas and oceans in a sense and that will have some impact on the environment. We still don’t know the kind of impact that it can have and not knowing is certainly a huge shortcoming in any form of development. It is believed that tidal barrages would have a similar impact as hydroelectric dams and one certainly doesn’t want such adverse consequences.

2. Tidal energy can be harnessed only if the barrages are closer to land or at the shores. This is challenging as developed coastlines are densely populated and having large scale operations close to cities or towns is undesirable.

3. Tidal energy is expensive to generate. Presently, the costs of setting up barrages or even the technology to harness the power of tides is very high. Experts claim that tidal energy would only become commercially viable circa 2020 when better technology and large scale projects would be developed. Right now, the investment is huge and the returns may not be feasible.