Do you know how does tide can be used as energy sources? In this article, we are going to study tidal energy and all other aspect related to tidal energy.
What’s in it for me?
- Introduction to tide and their formation
- What is Tidal Energy?
- Tidal Energy Power Generation methods
- Advantages of Tidal Energy
- Disadvantages of Tidal Energy
- Uses of Tidal Energy
- Conclusion
- FAQs
Introduction to tide and their formation
The rise and the fall of sea level are called tide. This happens because of the gravitational pull effect of the moon and the sun acting on the earth.
There are so many factors are responsible for the formation of the tide, but the Sun, moon, and the earth plays the most important factor.
As you all know that the moon is revolving around the earth and the earth is revolving around the sun.
As the smaller bodies revolve around the larger bodies because the gravitational pull of the larger body is more and it exerted on the smaller bodies.
Formation of tide
So while the moon is revolving around the earth its gravitational pull effect tries to pull the water on the earth that creates the tied on the surface of the ocean.
At the same time there will be tide formation on the other side of the earth as centrifugal forcing tries to counterbalancing the gravity of the earth.
That means there are two high tide formations on the earth at the same time at opposite directions of the earth and two low tide formation on both sides of the earth perpendicular to the moon.
Now as the sun is the biggest among the whole solar system its own gravitational pull be larger than the moon and the earth.
The sun can do two things here one is that it can increase the gravitational pull effect of the moon when the earth, moon and sun come in the straight line.
And second is the sun can diminish the moons gravitational pull effect when the earth and the moon at a right angle to the sun.
So when the sun increases the gravitational effect of the moon bigger tide formation happens in the ocean. These bigger high tides are called Spring Tide.
Whereas when the sun diminishes the moon’s gravitational pull effect it creates low tides which we called neap tides.
As you know the basics of the formation of the tides now we will dive deeper into this topic.
What is Tidal Energy?
Tidal energy is the energy that uses the kinetic energy of the moving water in the water bodies and potential energy due to the height difference between high and low tide to generate power or to do work.
So now we will see how tidal power is generated using this tidal energy.
Tidal Energy Power Generation methods
To converting the tidal energy into tidal power there are four major types of power generation methods.
Classified into four different generating methods:
Tidal stream generator
In this process, the turbines are places in the tidal stream. The tidal stream is nothing but the fast-moving body of water created by the use of tides. The turbine rotates using kinetic energy from these streams to generate electricity.
Tidal energy is more powerful than wind energy because turbines are rotated by the water not the air. And we all know water is denser compared to the air, it creates more power.
Tides are more predictable compare to the wind hence the electricity which is produced by tidal energy is more stable and reliable compare to wind power. The efficiency of the tidal power is much better to compare to wind power.
To generate the same amount of power using the same turbine wind need 90mph speed whereas tide only needs 10mph speed.
Placement of the turbines in the tidal stream is a very complex procedure as they are large in size and can sometimes become obstacles for tides. These turbines can be horizontal, vertical, open, or ducted also.
The world’s first-ever tidal power station was built in 2007 at Strangford Lough in Northern Ireland.
Tidal barrage
It uses the potential energy of tide due to the height difference between high and low tide. Barrage generator uses a large structure similar to a dam called barrage.
To create a large tidal basin across the inlet of the ocean they make barrage.
Sluice gates are there to control the water level inside the basin and flow of the water flowing over the electric turbine system.
A two-way tidal power generation system can use both the tide that is coming in the basin and going out of the basin to generate electricity.
The disadvantage of the tidal barrage system is a possible negative effect on plants and animals in estuaries of the tidal basin.
The tidal power plant in the Rance River estuary in Brittany, France constructed in 1996 used barrage.
Tidal lagoon
Construction of tidal lagoon is necessary In this type of tidal power generation.
It works similarly to the tidal barrage. It collects a large volume of water behind a natural or manmade structure and then allowed to rotate turbines and generate electricity.
Unlike the barrage, the lagoon can be constructed along the natural coastline. as these lagoons are filling and emptying continues power can generate.
Lagoons are built using natural materials like rocks therefore they have very minimal impact on the environment.
This lagoon appears like a speed barker in the ocean at the time of low tide and at the time of high tide they submerge in the water.
This Lagoon generates low energy as compared to other types mentioned above.
There is no functional tidal lagoon yet in the world but an iconic Swansea Bay Tidal Lagoon in South West Wales will become the world’s first tidal lagoon power plant.
Dynamic tidal power
Dynamic tidal power also known as DTP, nobody every used it in practical.
But very promising technology for tidal power generation. This theoretical technology makes full use of both kinetic and potential energy of tidal energy.
In this system long dam type structure is constructed perpendicular to the coastal line running into the sea. With the cost parallel barrier at the end forming the ‘T’ section.
This ‘T’ section will obstruct coast parallel tidal waves will create a level difference on the other side of the barrier which will drive the bi-directional turbines installed in the dam.
This was Dutch coastal engineers Kees Hulsbergen and Rob Steijn’s idea. In 1997 the receive their patent.
Advantages of Tidal Energy
- It is a renewable energy resource.
- It is not expensive to operate and maintain compared to other renewable energies.
- Low visual impact as the majority part of the tidal turbines submerged in the water.
- Noise pollution is very less as noise generated by the turbines, transfer through the water.
- Unlike wind, we can mostly predict high and low tides in advance.
- It provides protection against flooding and prevents losses.
- It is free and clean.
- Much effective at even low speed also.
- it creates jobs.
Disadvantages of Tidal Energy
- Not a constant source of energy as it depends on the gravitational effects of the moon and the sun.
- We must require a proper site, where the tides and tidal currents are consistently strong.
- It required high capital for construction and maintenance costs.
- It requires long underwater cables to transfer power from the submerged turbines to the grid.
- generate power ten hours a day during the ebb and flow of the tides.
- It might cause damage to the estuary ecosystem and coastal erosion.
- The concern of damage sea-life is there as they get stuck in the barrage or pass through the tidal turbine blades.
Uses of Tidal Energy
- Mainly used to generate electricity.
- Used for 100 of years for crushing grains in gain mills.
- We can use it as a storage of energy.
- It acts as protection from high storms.
Conclusion
Tidal energy is a kind of renewable energy that has great potential, it has the main advantage over other renewable energies Solar energy or Wind energy is its predictability. Because the ocean’s tidal patterns are predictable.
We knew that tidal energy is a much-anticipated source of energy. And that makes it highly attractive for electrical grid management.
It has also high density compared to the wind and solar energy which gives the turbine great efficiency leads to more power generation still the development in tidal energy is very less compare to other types of renewable energies.
This is mainly because of the specific site requirements are necessary to produce tidal power.
India has a 7500 km of coastline with immense potential for tidal energy. India’s estimated power potential is at about 12,455 megawatts (MW).
In 2011 Indian government imagined a 50 MW tidal energy plant in Gujarat that shows India’s inclination towards tidal energy.
But in march 2020 renewable energy minister R K Singh said in a written reply in Parliament “The government has not planned to harness tidal power due to high capital cost ranging from Rs. 30 crore to Rs. 60 crore per megawatt (MW)”.
Source: Economic Times
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FAQs
The turbine and generators convert the kinetic energy of the moment of water (Tide) into electricity.
Firstly, in the 19th century the use of falling water and sniping turbine to generate electricity was introduce to the world, and finally in 1966 the world’s first-ever large scale tidal power plant become operational.
Tidal energy is normally produced in a commercial size power plant called tidal power plants.
My name is Vivek Rawool. I am extremely motivated to constantly develop my skills and grow professionally. I have completed my BE Mechanical Degree from Mumbai University and currently working with Paramount India as a Sales and Marketing Engineer. I also do Share market trading and investment.
